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Students can Download Chapter 7 Alternating Current Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 7 Alternating Current

Plus Two Physics Alternating Current NCERT Text Book Questions and Answers

Question 1.
A 100Ω resistor is connected to a 220V, 50 Hz ac supply.

1. What is the rms value of current in the circuit?
2. What is the net power consumed over a full cycle?

Answer:
Given R = 100Ω, E_ν = 220V, ν = 50 Hz.
1. Since l_ν = \(\frac{E_{ν}}{12}\)
So l_ν = \(\frac{220}{100}\) = 2.2 A

2. P_aν = E_ν I_ν = 220 × 2.2
or P_aν = 484 W.

Question 2.

1. The peak voltage of an ac supply is 300V. What is the rms voltage?
2. The rms value of current in an ac circuit is 10A. What is the peak current?

Answer:
1. Given E₀ = 300 V, E_aν = ?
Since E_ν = \(\frac{E_{0}}{\sqrt{2}}\) = 0.707 × 300
or E_ν = 212.1V.

2. Given I_ν = 10A, I₀=?
Since l₀ = \(\sqrt{2}\) E_ν = 1.414 × 10
or I = 14.14 A.

Question 3.
A 44 mH inductor is connected to 220V, 50 Hz ac supply. Determine the rms value of the current in the circuit.
Answer:
Given L = 44 mH = 44 × 10^-3H
E_ν = 220V, ν = 50Hz, I_ν = ?
Since I_ν = \(\frac{E_{ν}}{x_{L}}=\frac{220}{\omega L}\)

or Iν = 15.9A.

Question 4.
A 60µF capacitor is connected to a 11OV, 60 Hz ac supply. Determine the rms value of the current in the circuit.
Answer:
Given C = 60µF = 60 × 10^-6F, E_ν = 110V, ν = 60 Hz.
Since I_ν = \(\frac{E_{ν}}{x_{c}}\)
∴ I_ν = ωCE_ν
= 2pνCE_ν = 2 × 3.142 × 60 × 60 × 10^-6 × 110
= 2.49A or
I_ν = 2.49V.

Question 5.
In Exercises 7.3 and 7.4, what is the net power absorbed by each circuit over a complete cycle. Explain your answer.
Answer:
In both the cases the net power consumed is zero because in both the cases.
Net power consumed P = E_ν l_νcosΦ
and Φ =90°
∴ P = 0 (in each case).

Question 6.
Obtain the resonant frequency of a series LCR circuit with L=2.0H, C=32µV and R = 10?. What is the Q-value of this circuit?
Answer:
Given L = 2.0H, C = 32µF = 32 × 10^-6F
R = 10Ω, Q = ?, ω₀ = ?
Resonant frequency

Question 7.
A charged 30µF capacitor is connected to a 27mH inductor. What is the angular frequency of free oscillations of the circuit?
Answer:
Given C = 30µF=30 × 10^-6F,L = 27mH = 27 × 10^-3H
ω₀ = ?

or ω₀ = 1.1 × 10^-3S^-1.

Plus Two Physics Alternating Current One Mark Questions and Answers

Question 1.
Which type of transformer you use to operate the coffee maker at 220 V?
Answer:
Step down transformer.

Question 2.
In an A C. circuit, I_rms and I_o are related as.

Answer:
(d) I_rms = \(\frac{I_{0}}{\sqrt{2}}\)

Question 3.
A capacitor of capacitance C has reactance X. If capacitance and frequency become double then reactance will be
(a)  4X
(b) X/2
(c) X/4
(d) 2X
Answer:
(c) Explanation

Question 4.
Fill in the blanks

• Impedance: admittance
• ……………..: conductance

Answer:
Resistance

Question 5.
Why it is better to use an inductor rather than a resistor to limit the current through the fluorescent lamp?
Answer:
No power is developed across the inductor as heat.

Question 6.
In an a.c circuit with phase voltage V and current I, the power dissipated is
(a) V.l
(b) Depends on phase angle between V and I
(c) \(\frac{1}{2}\) × V.I
(d) \(\frac{1}{\sqrt{2}}\)
Answer:
(b) Depends on phase angle between V and I

Plus Two Physics Alternating Current Two Mark Questions and Answers

Question 1.
Fill in the blanks.

Answer:
(i) Current lags by π/2
(ii) X_c = 1/cω
(iii) R
(iv) Phase difference is zero.

Question 2.
A.C. adaptor converts household ac into low voltage dc. A stepdown transformer is a essential part of ac adapter.

1. What is the use of step down transformer?
2. What is the principle of a transformer? Explain.

Answer:

1. To decrease voltage
2. It works on the principle of mutual induction.

Plus Two Physics Alternating Current Three Mark Questions and Answers

Question 1.
Match the following

Answer:

Question 2.

The following figure is a part of a radio circuit.

1. Identify the circuit.
2. What happens to this circuit if X_L = X_C
3. lf X_C > X_L draw the phaser diagram.

Answer:
1. LCR circuit.

2. When X_L = X_C, the impedance of circuit becomes minimum and the current corresponding to that frequency is maximum.

3.

Plus Two Physics Alternating Current Four Mark Questions and Answers

Question 1.
Figure below shows a bulb connected in an electrical circuit.

1. When the key is switched ON the bulb obtains maximum glow only after a shorter interval of time which property of the solenoid is responsible for the delay?

• Self-induction
• Mutual Induction
• Inductive reactance
• None of the above

2. If the flux linked with the solenoid changes from 0 to 1 weber in 2 sec. Find the induced emf in the solenoid.

3. If the 3v battery is replaced by an AC source with the key closed, what will be observation? Justify your answer.
Answer:
1. Self-induction.

2. \(\frac{d \phi}{d t}=\frac{1}{2}\) = 0.5V.

3. When AC is connected the brightness of bulb will be decreased. This is due to the back emf in the circuit.

Question 2.
A graph connecting the voltage generated by an a.c. source and time is shown.

1. What is the maximum voltage generated by the source?
2. Write the relation connecting voltage and time
3. This a.c. source, when connected to a resistor, produces 40J of heat per second. Find the equivalent d.c. voltage which will produce the same heat in this resistor.

Answer:

1. 200v.
2. V = V₀sin ωt
3. \(V_{\max }=\frac{V_{0}}{\sqrt{2}}=\frac{200}{\sqrt{2}}\) = 141.8v.

Question 3.
An inductor, capacitor, and resister are connected in series to an a.c. source V = V₀sin ωt.

1. Draw a circuit diagram of L.C.R. series circuit with applied a.c. voltage.
2. Find an expression for impedance of L.C.R. series circuit using phasor diagram.
3. What is impedance of L.C.R. series circuit at resonance?

Answer:
1.

2.

For impedance of LCR circuit.
From the right angled triangle OAE,
Final voltage, V = \(\sqrt{v_{n}^{2}+\left(v_{L}-v_{c}\right)^{2}}\)

Where Z is called impedance of LCR circuit

3. Impedance, Z=R.

Question 4.
A voltage source is connected to an electrical component X as shown in figure.

1. Identify the device X.
2. Which of the following equations can represent the current through the circuit?

• i = i_m sin(ωt + π/2)
• i = i_m sin(ωt – π/2)
• i = i_m sin ωt
• i = i_m sin(ωt + π/4)

3. Draw the phasor diagram for the circuit. (2)
Answer:
1. Resistor
2. i = i_m sin ωt
3.

Question 5.
A friend from abroad presents you a coffee maker when she visited you. Unfortunately, it was designed to operate at 110V line to obtain 960W power that it needs.

1. Which type of transformer you use to operate the coffee maker at 220V? (1)
2. Assuming the transformer you use as ideal, calculate the primary and secondary currents. (2)
3. What is the resistance of the coffee maker? (1)

Answer:
1. Step down transformer.

2. Since the transformer is ideal
V_pI_p = V_s I_s = 960W, V_p = 220v, V_s = 110v
V_pI_p =960

3.

Plus Two Physics Alternating Current Five Mark Questions and Answers

Question 1.
The voltage-current values obtained from a transformer constructed by a student is shown in the following table.

1. Identify the transformer as step up or step down.
2. How much power is wasted by the transformer?
3. What are the possible energy losses in a transformer?
4. If the input voltage is 48v and input current is 1 A, is it possible to light 240v, 100w bulb using the above transformer. Justify.

Answer:
1. Step down transformer.

2. Power loss = 200w -10w = 190w

3. The possible energy losses in a transformer:

• Eddy current loss
• Copper loss
• Hysteries loss
• Flux leakage

4. In this case input power = VI = 48 × 1 = 48W.
If transformer does not waste energy, input power =out put power.
Hence maximum output power 48W. But bulb requires 100w. Hence the bulb does not glow with this low input power.

Question 2.
The current through fluorescent lights are usually limited using an inductor.

1. Obtain the relation i = i_m sin(ωt – π/2)for an inductor across which an alternating emf v = v_m sin ωt is applied. (2)
2. Why it is better to use an inductor rather than a resistor to limit the current through the fluorescent lamp? (1)
3. When 100 V DC source is connected across a coil a current of 1 A flows through it. When 100V, 50 Hz AC source is applied across the same coil only 0.5 A flows. Calculate the resistance and inductance of the coil. (2)

Answer:
1. AC voltage applied to an Inductor

Consider a circuit containing an inductor of inductance ‘L’ connected to an alternating voltage. Let the applied voltage be
V = V₀ sinωt…………(1)
Due to the flow of alternating current through coil, an emf, \(\mathrm{L} \frac{\mathrm{d} \mathrm{I}}{\mathrm{dt}}\) is produced in the coil. This induced emf is equal and opposite to the applied emf (in the case of ideal inductor).

2. No power is developed across the inductor as heat.

3. Resistance of the coil R = \(\frac{v}{I}=\frac{100}{1}\) = 100Ω. Current through the coil when ac source is applied.

R² + X²_L = 200²
X²_L = 200² – 100²
X_L = 173.2Ω
L_ω = 173.2

Question 3.
An alternating voltage is connected to a box with some unknown circuital arrangement. The applied voltage and current through the circuit are measured as v = 80 sinωt volt and i = 1.6 sin(ωt + 45°) ampere.

1. Does the current lead or lag the voltage?
2. Is the circuit in the box largely capacitive or inductive?
3. Is the circuit in the box at resonance?
4. What is the average power delivered by the box?

Answer:
1. Leads.

2. Capacitive

3. No Hint: Current and voltage are not in the same phase.

4. P = V_rmsl_rmsCosΦ, V_m = 80v, i_m = 1.6A

p = 45.25W

Students can Download Chapter 5 Organising Questions and Answers, Plus Two Business Studies Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Business Studies Chapter Wise Questions and Answers Chapter 5 Organising

Plus Two Business Studies Organising One Mark Questions and Answers

Question 1.
Which level of managers are responsible for determining formal organisation?
Answer:
Top level management

Question 2.
Name the type of organisation which does not have any predetermined objectives.
Answer:
Informal organisation

Question 3.
In ABC Ltd. all the decisions are taken by top level management only. Which policy is followed by organisation?
Answer:
Centralisation.

Question 4.
‘It is an organisation which is consciously coordinated towards a common objective’. State the type of Organisation.
Answer:
Formal organisation.

Question 5.
An organisation officially created by the management is called
Answer:
Formal organisation.

Question 6.
Name the organisation which emerges due to authority-responsibility relationship.
Answer:
Formal organisation.

Question 7.
A network of social relationship that arises spontaneously due to interaction at work is called.
Answer:
Informal organization

Question 8.
The form of organisation known for giving rise to rumours is called
Answer:
Informal organisation

Question 9.
In an organisation, the network of small social groups based on friendship is called
Answer:
Informal organisation

Question 10.
This structure is followed by large scale service organisation whose activities are geographically spread. Identify the type of organisation structure
Answer:
Divisional organisation.

Question 11.
Which of the following is not an element of delegation?
(a) Accountability parole
(b) Authority
(c) Responsibility
(d) Informal organisation
Answer:
(d) Informal organisation

Question 12.
A company has its registered office in Delhi, manufacturing unit at Chennai and marketing and sales department at Bangalore. The company manufactures consumer products. Which type of organisational structure should it adopt to achieve its target?
Answer:
Divisional organisation.

Question 13.
Which organisational structure is suitable for a multiproduct manufacturing company?
Answer:
Divisional organisation

Question 14.
Which organisational structure is suitable for a uni-product manufacturing company?
Answer:
Functional organisation

Question 15.
In this structure, activities are grouped on the basis of function. Identify the organisation structure.
Answer:
Functional organisation

Question 16.
Grouping of activities on the basis of product lines is a part of
(a) Delegated organisation
(b) Divisional organisation
(c) Functional organisation
(d) Autonomous organisation
Answer:
(b) Divisional organisation

Question 17.
Participation of lower levels in management is
Answer:
Decentralisation

Question 18.
Suggest the most suitable terminology to describe “the systematic dispersal of authority to the lower levels”.
Answer:
Decentralisation.

Question 19.
‘It is the right to give orders and the power to exact obedience.’ This is called
Answer:
Authority.

Question 20.
Name the concept which reduces the workload of a manager.
Answer:
Delegation of Authority.

Question 21.
Anything that goes to increase the importance of subordinates is called
Answer:
Decentralisation.

Question 22.
The technical term4which denotes the number of subordinates that a superior can effectively supervise.
Answer:
Span of control.

Question 23.
The following are different steps involved in the process of Organising.
(i) Grouping of similar jobs.
(ii) Division of work.
(iii) Co-ordination of activities.
(iv) Creation of authority relationship
Which of the following sequence is correct?
(a) iv, iii, i, ii
(b) ii, i, iv, iii
(c) ii, i, iii, iv
(d) iv, i, ii, iii
Answer:
(b) ii, i, iv, iii

Question 24.
Match the following.

Answer:
(a) → ii)
(b) → iv)
(c) → i)
(d) → iii)

Question 25.
Span of management refers to
(a) Number of managers
(b) Length of term for which a manager is appointed
(c) Number of subordinates under a superior
(d) Number of members in top management.
Answer:
(c) Number of subordinates under a superior

Plus Two Business Studies Organising Two Mark Questions and Answers

Question 1.
What is meant by organising?
Answer:
Organising is one of the most important functions of management, which includes

1. Identifying and grouping the work to be performed.
2. Defining and delegating authority and responsibility.
3. And establishing relationships for the purpose of accomplishing objectives.

Question 2.
What do you mean by organisation as ‘process’?
Answer:
The process of organising involves division of work, grouping of jobs into departmentation, establishing authority relationships and co-ordination of activities. Therefore organising is treated as a process.

Question 3.
State the circumstances in which functional organisation is more suitable.
Answer:
It is most suitable when the size of the organisation is large and, has diversified activities and operations require a high degree of specialisation

Question 4.
Mr. Satheesh Babu, the General Manager of Venad automobiles decided to share some of his work with his newly appointed assistant manager Mr. Raju. This helped him to concentrate more on important tasks. Which management concept is referred here?
Answer:
Delegation of Authority:
Delegation means the granting of authority to subordinates to operate within the prescribed limits. It enables the manager to distribute his workload to others so that he can concentrate on important matters.

Question 5.
Suggest the most appropriate term used to describe the process of entrusting part of the work by the superior to his subordinates.
Answer:
Delegation of Authority:
Delegation means the granting of authority to subordinates to operate within the prescribed limits. It enables the manager to distribute his workload to others so that he can concentrate on important matters.

Plus Two Business Studies Organising Three Mark Questions and Answers

Question 1.
Why does informal organisation exist within the framework of formal organisation? Give any two reasons for the emergence of informal organization
Answer:

1. To fulfil the social needs of the members.
2. To make the communication easy.

Advantages

• There can be faster spread of communication.
• It helps to fulfil the social needs of the members and this enhances their job satisfaction.
• Top level managers can know the real feedback of employees on various policies and plans.

Question 2.
In a classroom discussion Saleem, a Plus Two Commerce student, argues that delegation and decentralisation are one and same.

1. Do you agree with his argument?
2. Give any two points to justify your answer.

Answer:

1. I am not agreeing with this statement
2. Difference between Delegation and Decentralisation

 

Delegation	Decentralisation
It is the entrustment of authority and responsibility from one individual to another.	It is a systematic delegation of authority from one level to another level.
Responsibility cannot be delegated.	Responsibility can be delegated.
Delegation is a compulsory act.	Decentralisation is an optional policy decision.
More control by superiors hence less freedom to take own decisions. it is individualistic.	Less control over executives hence greater freedom of action. It is totalistic.

Plus Two Business Studies Organising Four Mark Questions and Answers

Question 1.
‘It is an organisation which is consciously coordinated towards a common objective’.

1. What this organisation is called?
2. State any 3 important features of this organisation.

Answer:
1. This is a formal organisation.
2. The important features are:

• It is deliberately created by the top management to achieve the objectives.
• It is based on division of labour and specialisation.
• It is impersonal – Does not take into consideration emotional aspect of employees.
• It clearly defines the authority and responsibility of every individual.^
• The principle of scalar chain is followed informal organisation

Question 2.
The employees of Manik Ltd., a software company, have formed a Dramatic group for their recreation.

1. Name the type of organisation so formed.
2. State its three features.

Answer:
1. Informal organisation
2. features are:

• It originates from within the formal organisation as a result of personal interaction among employees.
• It has no written rules and procedures.
• It does not have fixed lines of communication.
• It is not deliberately created by the management.
• It has no definite structure.

Question 3.
Explain the differences between Formal Organisation and informal Organisation.
Answer:

Formal organisation	Informal organisation
1) It is deliberately created by top-level management.	1) It arises automatically as a result of social interaction among the employees.
2) It has a pre-determined purpose.	2) It has no pre­determined purpose.
3) It is highly rigid.	3) It is more flexible.
4) Communication is allowed through the scalar chain.	4) Communication is allowed through all channels networks.
5) Managers are leaders.	5) Leaders are chosen voluntarily by the members.
6) It is based on authority and responsibility.	6) There is no authority and responsibility relationship.

Question 4.
Delegation of authority is based on the elementary principle of division of work. Explain.
Answer:
In division of work, the work is divided into small tasks. Same way in the delegation, the manager divides some of his work and authority among his subordinates.

No manager can perform all the functions himself. To get the work done efficiently and in a specialized manner, the manager divides the work among his subordinates according to their qualification and capability.

Plus Two Business Studies Organising Five Mark Questions and Answers

Question 1.
“Formal organisation when blends with informal organisation result in organisational success.” Comment.
Answer:
Formal organisation refers to intentional structure of well-defined jobs informally organised enterprises. Such jobs are well defined in terms of authority, responsibility and accountability. It is based on division of labour and specialisation.

But informal organisation refers to relationship between individuals in the organisation based on interest, personal attitude, emotions, likes, dislikes etc.

The informal organisation is a part of the formal organisation; it cannot be separated. They are the two aspects of the same organisation and are linked to each other. Both are required for the success of an organisation.

Question 2.
“It is an organisation structure followed by large scale service organisations whose activities are geographically spread”.

1. Find out the organisation structure.
2. State its merits and demerits.

Answer:
1. It is divisional organisation.

2. merits and demerits are:
Divisional Structure:
Grouping of activities on the basis of different product manufactured are known as divisional structure of organisation. Each division has a divisional manager responsible for performance. Each division is multifunctional because within each division functions like production, marketing, finance etc. are performed together to achieve a common goal.

Advantages:

1. Each division functions as an autonomous unit which leads to faster decision making.
2. It helps in fixation of responsibility in cases of poor performance of the division
3. It helps to develop the skill of the divisional head.
4. It facilitates expansion and growth as new divisions can be added without interrupting the existing operations.

Disadvantages

1. Conflict may arise among different divisions with reference to allocation of funds.
2. It may lead to increase in costs since there may be a duplication of activities across products.
3. It is not suitable for small organisations.

Question 3.
Arunima Pvt. Ltd. is a new company for manufacturing soaps at Mysore. They decided to have four functional departments – viz, Production, Marketing Finance and Administration.

1. Recommend the most suitable organisation structure of the company.
2. Give the diagrammatic representation of this organisational structure.

Answer:
1. It is functional organisation

2. organisational structure are:
Divisional Structure:
Grouping of activities on the basis of different product manufactured are known as divisional structure of organisation. Each division has a divisional manager responsible for performance. Each division is multifunctional because within each division functions like production, marketing, finance etc. are performed together to achieve a common goal.

Advantages:

1. Each division functions as an autonomous unit which leads to faster decision making.
2. It helps in fixation of responsibility in cases of poor performance of the division
3. It helps to develop the skill of the divisional head.
4. It facilitates expansion and growth as new divisions can be added without interrupting the existing operations.

Disadvantages

1. Conflict may arise among different divisions with reference to allocation of funds.
2. It may lead to increase in costs since there may be a duplication of activities across products.
3. It is not suitable for small organisations.

Question 4.
Identify the organisation structure of a transport company having operations throughout India. Explain.
Answer:
It is divisional structure.
Types of Organisation Structures:
The organisational structure can be classified as undertwo categories.

1. Functional Organisation
2. Divisional Organisation

Question 5.
Distinguish between functional organisation and divisional organisation.
Answer:

Functional Structure	Divisional Structure
1. Formation is based on functions	1. Formation is based on product lines.
2. Functional specialisation	2. Product specialisation
3. Difficult to fix responsibility on a department	3. Easy to fix responsibility for performance
4. It is economical	4. It is costly.
5. Suitable for small organisation	5. Suitable for big organisation

Question 6.
“Delegation of authority leads to reduction in the workload of superiors.” In the light of this statement, comment briefly on the importance of delegation of authority.
Answer:
a. Delegation of Authority:
Delegation means the granting of authority to subordinates to operate within the prescribed limits. It enables the manager to distribute his workload to others so that he can concentrate on important matters.

b. Importance of Delegation of Authority:

1. Reduces the work load of managers:
The managers are able to function more efficiently as they get more time to concentrate on important matters.

2. Employee development:
Delegation empowers the employees by providing them the chance to use their skills,’gain experience and develop themselves for higher positions.

Plus Two Business Studies Organising Eight Mark Questions and Answers

Question 1.
“Organising is the backbone of management and it contributes to the success of an enterprise”. Point out your arguments in favour of this statement.
Answer:
a. Organising is one of the most important functions of management which includes:

1. Identifying and grouping the work to be performed.
2. Defining and delegating authority and responsibility.
3. And establising relationships for the purpose of accomplishing objectives

b. Importance of Organising
1. Specialisation:
Since the activities are divided into convenient jobs and are assigned to a particular employee, it leads to specialisation, more productivity and efficiency.

2. Clarity in working relationship:
It helps in creating well-defined jobs and also clarifying authority – responsibility relationship between the superior and subordinates.

3. Optimum utilisation of resources:
The proper assignment of jobs avoids overlapping of work and also makes possible the best use of resources.

4. Adaptation of change:
It allows a business enterprise to adapt itself according to changes in the business environment.

5. Effective administration:
Clarity in working relationships enables proper execution of work and brings effectiveness in administration.

6. Development of personnel:
Organising stimulates creativity amongst the managers and subordinates.

7. Expansion and growth:
Organising helps in the growth and diversification of an enterprise by adding more job positions, departments and product lines.

Question 2.
ABC Ltd is a newly registered company. As a commerce student, can you help the management by providing the various steps involved in the managerial organisation functions?
Answer:
Step in the Process of Organising
1. Division of Work:
The first step in the process of organising involves identifying and dividing the work that has to be done. Division of work leads to specialisation.

2. Departmentation:
The second step is to group similar or related jobs into larger units, called departments. The grouping of activities is known as departmentation.

3. Assignment of duties:
The next step is to allocate the work to various employees according to their ability and competencies.

4. Establishing authority – responsibility relationship:
The last step is creation of authority – responsibility relationship among the job positions. It helps in the smooth functioning of the organisation.

Question 3.
Mr. Hassan, the General Manager of Almonsa Ltd. has decided to give some responsibility and decision making authority to the different levels of management so that he will be relieved of all daily routine activities.

1. What is the concept referred to?
2. State the benefit derived through this process.
3. How does it differ from delegation of authority?

Answer:
1. Delegation of Authority:
Delegation means the granting of authority to subordinates to operate within the prescribed limits. It enables the manager to distribute his workload to others so that he can concentrate on important matters.

2. Importance of Delegation of Authority:

a. Reduces the workload of managers:
The managers are able to function more efficiently as they get more time to concentrate on important matters.

b. Employee development:
Delegation empowers the employees by providing them with the chance to use their skills, gain experience and develop themselves for higher positions.

c. Motivation of employees:
Responsibility for work builds the self-esteem of an employee and improves his confidence. He feels encouraged and tries to improvers performance.

d. Facilitation of growth:
Delegation helps in the expansion of an organisation by providing a ready workforce to take up leading positions in new ventures.

e. Superior-subordinate relations:
Delegation of authority establishes superior-subordinate relationships, which are the basis of hierarchy of management.

f. Better co-ordination:
The elements of delegation – authority, responsibility and accountability help to avoid overlapping of duties and duplication of effort

 

Students can Download Chapter 7 Ecosystem Questions and Answers, Plus Two Botany Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Botany Chapter Wise Questions and Answers Chapter 7 Ecosystem

Plus Two Botany Ecosystem One Mark Questions and Answers

Question 1.
The 10% law is associated with an important function of an ecosystem is
(a) Productivity
(b) Nutrient cycling
(c) Decreases the calorific value in successive trophic levels
(d) Increases the calorific value in successive trophic levels.
Answer:
(c) Decreases the calorific value in successive trophic levels

Question 2.
In the second step of trophic level, the energy storage is primarily associated with
(a) gross primary productivity
(b) net primary productivity
(c) secondary productivity
(d) none of the above
Answer:
(c) secondary productivity

Question 3.
If the energy storage at second trophic level is 4000 KJ what is the energy level of primary and secondary carnivore?
Answer:
In primary carnivore level the energy storage is 400 KJ while in second carnivore level it is 40 KJ.

Question 4.
Give an example for gaseous and sedimentary cycle
Answer:

• Gaseous cycle -Nitrogen cycle
• Sedimentary cycle – Phosphorus cycle

Question 5.
Which is the community next to lichen that occur in xerarch succession.
Answer:
Moss stage

Question 6.
In food chain transfer of energy takes place from one tropic level to the next is
(a) 5%
(b) 10%
(c) 15%
(d) 20%
Answer:
(b) 10%

Question 7.
The second trophic level in a lake is………….
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes
Answer:
(b) Zooplankton

Question 8.
Food chain in which microorganisms breakdown the food formed by primary producers
(a) Parasitic food chain
(b) Detritus food chain
(c) Consumerfoodcahin
(d) Predator food cahin
Answer:
(b) Detritus food chain

Question 9.
What is true of ecosystem?
(a) Primary consumers are least dependent upon producers
(b) Primary consumers out number producers
(c) Producers are more than primary consumers
(d) Secondary consumers are the largest and most powerfull
Answer:
(c) Producers are more than primary consumers

Question 10.
Which of these statements is correct?
(a) The base of the energy pyramid contains the largest trophic level.
(b) About 10% of energy available in food is actually incorporated into any trophic level.
(c) Humans are at the top of energy pyramids.
(d) All of these
Answer:
(d) All of these

Question 11.
The energy pyramid is always upright because the energy content
(a) decreases in successive trophic levels
(b) increases in successive trophic levels
(c) increases from the base to the top
(d) decreases from primary consumer to secondary consumer only
Answer:
(a) decreases in successive trophic levels

Question 12.
Which one of the following is not coming under decomposition
(a) catabolism
(b) anabolism
(c) mineralization
(d) the surface area of detritus increases
Answer:
(b) anabolism

Question 13.
Most useful step of decomposition for plants is
(a) mineralization
(b) catabolism
(c) humification
(d) fragmentation of detritus
Answer:
(a) mineralization

Question 14.
Food chains are not always linear, it is branched in some steps. Name the network of food chains.
Answer:
The network of the food chain is called food web.

Question 15.
The biotic community along with physical environment forms an interacting system called………..
Answer:
Ecosystem

Question 16.
If the energy storage at second trophic level is 4000 KJ what is the energy level of primary and secondary carnivore?
Answer:
In primary carnivore level the energy storage is 400 KJ while in second carnivore level it is 40 KJ.

Question 17.
Cite an example of an inverted ecological pyramid.
Answer:
Pyramid of number in tree ecosystem & pyramid of biomass in sea ecosystem is inverted.

Question 18.
Which among the following equation is related with net primary productivity?
(a) GPP + R = NPP
(b) NPP + GPP = R
(c) GPP – R = NPP
(d) R + R = GPP
Answer:
(c) GPP-R = NPP

Question 19.
Find out the stage given below which is not included in hydrarch succession.
(a) Forest
(b) Phytoplanktons
(c) Lichens
(d) Marsh-Meadow
Answer:
(c) Lichens

Question 20.
Which among the following decomposers.
(a) Autotrophs
(b) Saprotrophs
(c) Heterotrophs
(d) Herbivores
Answer:
(b) Saprotrophs

Question 21.
Which one of the following is a primary consumer in an aquatic ecosystem.
(a) Phytoplanktons
(b) Aquatic birds
(c) Zooplanktons
(d) Large Fishes
Answer:
(d) Zooplanktons

Plus Two Botany Ecosystem Two Mark Questions and Answers

Question 1.
GPP-R= NPP is an equation indicating productivity. Illustrate the terms denoted in the equation.
Answer:
GPP is the gross primary productivity which is the rate of production of organic matter during photosynthesis. R- is the respiration loses which is the amount of GPP utilized by plants in respiration. NPP is the available biomass for the consumption to hetrotrophs. (Herbivores and Decomposers).

Question 2.
Decomposition is the breakdown of complex organic matter into inorganic substances like C0₂, Water, etc.

1. Identify the gas which is most essential for decomposition.
2. Find out any two conditions which inhibit decomposition.

Answer:

1. Oxygen
2. Low temperature Anaerobiosis

Question 3.
Vast area of vegetation is destroyed mostly by fires and it results in clearing of lush vegetation. How long it takes to re-form climax community. Name the process is related in the above case.
Answer:
Time taken is about 50-100 years in case of a grassland and about 100-200 years for a forest. Secondary succession.

Question 4.
Healthy ecosystems are the base for a wide range of goods and services. Find out any four ecosystem services provided by a healthy forest ecosystem.
Answer:

1. Purify air and water
2. Mitigate drought and floods
3. Cycling of nutrients
4. Generate fertile soils

Question 5.
Differentiate between Standing state and Standing Crop.
Answer:
1. Standing crop
The amount of living material present in each trophic level.

2. Standing state
The amount of nutrients like carbon, nitrogen, phosphorus, calcium, etc present in the soil at a given time.

Question 6.
Distinguish between Grazing food chain and Detritus food chain.
Answer:
1. Grazing food chain
It starts with producers. In aquatic ecosystem major fraction of energy flow take place through GFCthan DFC.

2. Detritus food chain
It starts with detritus. In terrestrial ecosystem major fraction of energy flow take place through DFC than GFC.

Question 7.
Xerarch succession is mainly occurs in desert conditions

1. Name the pioneefspecies on a bare rock.
2. How do pioneer species help in establishing the next type of vegetation.

Answer:

1. Lichens
2. They secrete carbonic acid and dissolve rocks. This process forms soil to help growth of mosses.

Question 8.
Energy flow is always unidirectional, never return back. Do you agree. Give the justification of your answer.
Answer:
Yes. The flow of energy is based on thermodynamic laws.lt starts from producers and flows through successive trophiclevels, The efficiency of energy transfer from one trophic level to the next is 10%.

Question 9.
A Volcano erupted in Hawaii, and lava covered land that had been framed for centuries. Eventually, new lichens, and then plants, grew on the lava.

1. Is this an example of primary or secondary successions?
2. Give the reason also.

Answer:

1. This is an example of primary succession
2. Because it begins from a state of little or no life.

Question 10.
Decomposition is the process in which complex dead matters are broken down into simpler inorganic substances,

1. Name the step of decomposition in which biological activity not found?
2. Chemical composition of detritus influence decomposition why?

Answer:

1. Humification
2. If the detritus rich in Lignin and c.hitinthe rate of decomposition is very slow but it is rich in nitrogenous compounds and Sugars the rate of decomposition is very high.

Question 11.
Decaying Biomass is formed through the process of decomposition, from which different types of mineral ions are released based on the mineralisers act on it.

1. Name the microorganisms that helps to release phosphate and nitrate into the soil
2. Give an example for nutrient cycling that helps in the photosynthesis of land plants.

Answer:

1. Phosphate solubilizing bacteria and nitrifying bacteria
2. Carbon cycle

Question 12.
In Barren lands succession continuous and forms climax vegetation after many years

1. Name the Pioneer community formed.
2. Which is the community comes next to Pioneer community?

Answer:

1. lichen
2. bryophytes

Question 13.
Productivity is one of the key function of an ecosystem, it varies in different ecosystems.

1. Distinguish between primary productivity and secondary productivity.
2. Some Terrestrial ecosystem shows abundant and least productivity. Name it.

Answer:

1. The primary productivity is associated with producers while secondary productivity is associated with consumers.
2. Abundant productivity is found in tropical rainforest Least productivity is found in desert.

Question 14.
How can you differentiate primary productivity from secondary productivity?
Answer:

1. Primary productivity-productivity at producer level
2. Secondary productivity – productivity at consumer level

Question 15.
Mention the functions of ecosystem.
Answer:

• Productivity
• Decomposition
• Energy flow
• Nutrient cycling

Question 16.
Connect the terms in the column A with suitable definition given below and fill up column B.

(a) Rate of biomass production.
(b) Rate of storage of organic matter by producers in excess of their metabolic consumption.
(c) Rate of production of organic matter by plants during photosynthesis.
(d) Rate of formation of new organic matter by consumers.
Answer:

1. b
2. c
3. a
4. d

Question 17.
Measurement of biomass in terms of dry weight is more accurate than fresh weight. Why?
Answer:
Fresh Weight contains weight of water present inside the cells as cell sap. Where as dry weight is the actual weight of the materials making up the body of the organism.

Question 18.
Leaching, detritus, catabolism, humification, fragmentation, mineralization, detritivores, humus. Given above are the terms involved in the process of decomposition. Arrange them in correct sequence.
Answer:
Detritus ? detritivore ? fragmentation ? leaching ? catabolism ? humification ? humus ? Mineralization.

Question 19.
The given table shows the dry weight of different trophic levels of forest ecosystem.

Trophic level	Dry wt. (Kgm-2)
PP	809 kgm-2
PC	37 kgm-2
SC	11 kgm-2
TC	1.5 kgm-2

1. From the given data construct a pyramid of biomas.

2. if you select Lake ecosystem to construct pyramid of biomas, it contain producers (Phytoplanktons), Herbivores (Short lived fishes) and Carnivores (Long lived fishes) with dry weight 2mgm-3, 7mgm-3 and 9mgm-3 respectively. From the data construct a pyramid of biomas.
Answer:
1.

2.

Question 20.
Energy is an important key functional component of ecosystem and pyramid of energy is always upright.

1. Do you agree with this statement.
2. Give reason.

Answer:

1. Yes
2. Energy transfer in a pyramid follows the ll nd law of thermodynamics . It also obeys the 10 % law (only 10 % of energy is transferred to each tropic level from the lower tropic level).

Question 21.
In nature there is no independent food chain.

1. Do you agree with the statement? Justify?
2. Decomposers have important role in nutrient cycling. Substantiate.

Answer:
1. Yes. The members of one food chain depends the members of other food chains and forms interconnections.

2. Detritus or dead remains are broken down by detritivores catabolism results in breaking down of complex molecules by decomposers. This results in the formation of mineral nutrients into the soil, thereby recycling of nutrients are achieved.

Question 22.
While visiting a forest, Ranjan’s grandfather told that long back it was a pond.

1. Name the phenomenon takes place here.
2. Write down the different stages of that process.

Answer:

1. Hydrach
2. Phytoplankton stage – Submerged plant-stage – Submerged free floaloting plant stage – Reed swamp stage – Marsh meadow stage — Scrub stage – Forest stage.

Question 23.
Human activities have a significant role in carbon cycle.

1. Do you agree with the statement?
2. Mention the environmental hazard caused by excess release of CO₂?

Answer:
1. Yes.

2. Deforestation activities and massive burning of fossil fuels increase the amount of CO₂ in the atmosphere that causes reradiation of reflected solar radiations. This leads to heating of the troposphere called green house effect.

Question 24.
Ecological succession and species evolution would have been a parallel process. Justify.
Answer:
As succession gives to the replacement of one community by another and establishment of dominant species it can be considering as parallel steps to evolution.

Question 25.
Sedimentary cycle that occure in lithosphere

1. Give an example for sedimentary cycle.
2. Give a flow chart representing the above cycle.

Answer:
1. Phosphorous cycle.

2. The cycle consists of following steps.

Question 26.
The atmosphere contains only about 1% of total global carbon. But carbon cycle is an gaseous cycle since the reservoir is atmospheric CO₂. Justify.
Answer:
71% of carbon is found dissolved in oceans which regulates the amount of CO₂ in the atmosphere. Fossil fuels also represents a reservoir of carbon. Carbon cycle is considered as gaseous cycle since the cycling occurs through atmosphere, ocean and through living and dead organisms.

The CO₂ is released to the atmosphere by burning of fuels, processing of waste materials in land and ocean and hence it act as a reservoir of CO₂ in an ecosystem.

Question 27.
Why is the length of a food chain in an ecosystem generally limited to 3-4 trophic levels?
Answer:
Energy requirement for maintenance of body rises successively with higher level. As 90% energy is lost when it moves from one trophic level to the next, the residual energy decreases drastically within 2-3 trophic levels, as a result an ecosystem can support only limited number of trophic levels.

Question 28.
Name the type of food chain responsible for the flow of larger fraction of energy in aquatic and a terrestrial ecosystem respectively. Mention one difference between two food chains.
Answer:
In an aquatic ecosystem GFC is the major conduits for energy flow where as in terrestrial ecosystem a much larger fraction of energy flow through the detritus food chain than through the GFC. Detritus food chain may be connected with the grazing food chain at some levels.

Difference between two food chains:
Detritus food chain always start with dead organic matter where as GFC starts with plants.

Question 29.
A volcano erupted in Hawaii, and lava covered land that had been framed for centuries. Eventually new lichens and then plants grew on the lava.

1. Is this an example of primary or secondary successions ?
2. Give the reason.

Answer:

1. Yes
2. This is an example of primary succession because this begins from a state of little or no life.

Question 30.
Distinguish between grazing and detritus food chain. Name the type of food chain helps in the flow of major fraction of energy through aquatic ecosystem.
Answer:

• The food chain start with producers are called grazing food chain.
• It start with dead organic matters is called detritus food chain.
• In an aquatic ecosystem, majorfraction of energy flow occurs through GFC.

Question 31.
In lake ecosystem .biomass of trophic levels are different

1. Do you agree the pyramid of biomass is inverted.
2. Give reason.

Answer:

1. Yes
2. In lake ecosystem producers are phyto-planktons. The short lived and long lived fishes are arranged above the lelvel of producers.Here biomass is increased from base to the top of pyramid.

Question 32.
How much PAR is used by producers for gross primary productivity?
Answer:
Of the incident solar radiation less than 50 percent of it is photosynthetically active radiation(PAR. Plants capture only 2-10 per cent of the PAR for gross primary productivity.

Question 33.
Differentiate between a detrivore and a decomposer giving an example of each.
Answer:
Detrivores are the primary consumers of a detritus food chain which feed upon the detritus and include protozoan, bacteria, and fungi, while decompers form the last trophic level of both detritus and grazing food chains and break down complex organic compounds of dead plants and animals and include bacteria and fungi.

Question 34.
Why is the length of a food chain in an ecosystem generally limited to 3-4 trophic levels?
Answer:
Energy requirement for maintenance of body rises successively with higher level. As 90% energy is lost when it moves from one trophic level to the next, the residual energy decreases drastically within 2 – 3 trophic levels. As a result an ecosystem can support only a limited number of trophic levels.

Question 35.
Due to uncontrolled excessive hunting the population of tigers in a forest becomes zero. What are the long term effects of this situation on the population of deer in that forest.
Answer:
The reduction in predator population may result in the increase of prey population (deer), since they are not preyed upon. Increase in the number of deer will lead to overgrazing, hence, shortage of herbs and eventually reduction in the number of deer.

Question 36.
A Volcano erupted in Hawaii, and lava covered land that had been framed for centuries. Eventually, new lichens, and then plants, grew on the lava. Is this an example of primary or secondary successions? Give the reason also.
Answer:
This is an example of primary succession Because this begins from a .state of little or no life.

Question 37.
How can you differentiate primary productivity from secondary productivity?
Answer:

1. Primary productivity-productivity at producer level
2. Secondary productivity – productivity at consumer level

Question 38.
Observe the flow chart on functional components of ecosystem given below.

1. Identify the components given as A and B
2. What is stratification?

Answer:
1. components given as A and B:
A = Energy flow
B = Nutrient cycling

OR

A = Nutrient cycling
B = energy flow

2. Vertical distribution of different species occupying different levels.

Question 39.
Observe the food chain given below. Grass? Goat? Man

1. Identify the type of food chain,
2. How does it differ from detritus food chain?

Answer:

1. Grazing Food Chain
2. Grazing food chain starts with producers while detritus food chain starts with dead organic matter.

Question 40.
Given below is the flow chart of ecological succession occur in water bodies.

1. Identify the stages A, B, C, D, E and F
2. What is this succession called?

Answer:
1. The stages A, B, C, D, E, and F:

• A = Submerged plant stage
• B = Submerged free floating plant stage
• C = Reed-swamp stage
• D = Marsh-meadow stage
• E = Scrub stage
• F = Forest stage

2. Hydrarch succession

Question 41.
Given below is a simplified model of a nutrient cycling in a terrestrial ecosystem.

1. Identify the cycle?
2. How does it differ from a gaseous cycle?

Answer:

1. Phosphorus cycle
2. This cycle starts from earth’s crust(lithosphere) but gaseous cycle exists in atmosphere.

Question 42.
Decomposition of detritus is a complex process. Decomposition has various steps. Identify the steps given below and fill the blanks.

Answer:

1. Fragmentation
2. Leaching
3. Catabolism
4. Humification

Question 43.
Decomposition is the breakdown of complex organic matter into inorganic substances like CO₂, Water, etc.

1. Identify the gas which is most essential for decomposition.
2. Find out any two conditions which inhibit decomposition.

Answer:

1. Oxygen
2. Low temperature, Anaerobiosis.

Question 44.
In most ecosystems, all the pyramids of number, biomass, and energy are upright. Suggest on occasion each where the pyramid of number and pyramid of biomass are inverted.
Answer:
When a big tree is considered as an ecosystem- pyramid of number is inverted. Pyramid of biomass in sea is also inverted.

Question 45.
Ecological pyramids express the food or energy relationship between organisms, Write any three limitations of ecological pyramids.
Answer:

1. In some cases same species may belong to two or more trophic levels
2. It does not represent food web
3. Saprophytes are not given any place

Question 46.
Analyze the table given below and fill in the blanks suitably.

Answer:

1. Standing crop
2. The amount of nutrients presents in the soil or eosystem at any given time

Question 47.
Match the items of column A with column B
VAnswer:
(a) – (v)
(b) – (iii)
(c) – (ii)
(d) – (i)

Question 48.
Human activities have significantly influenced the carbon cycle by increasing the amount of C02- production. Justify this statement with minimum two points.
Answer:

1. It lead to rapid deforestation.
2. Massive burning of fossil fuel for energy and transport.

Question 49.
Given below is simplified mode of a biogeochemical cycle.
Fill up the blanks a), b), c) and d)

Answer:

1. Rock minerals
2. Producers
3. Consumers
4. Detritus

Question 50.
Construct a pyramid of biomass using the data given below.
PC 37Kgm^-2 TC 1.5Kgm^-2
PP 809Kgm^-2 SC 11Kgm^-2
Answer:

Question 51.
Carbon cycle and phosphorus cycle are two common biogeochemical cycles. Write any three differences between these two cylces.
Answer:

Carbon cycle	Phosphorous cycle
1. Gaseous cycle 2. Respiratory release into atmosphere 3. Atmospheric input through rainfall very high	a)  Sedimentary cycle b)  No respiratory release c)  Atmospheric input through rainfall is very low

Plus Two Botany Ecosystem Three Mark Questions and Answers

Question 1.
Primary succession is a long term process, while secondary succession is a short term process.

1. Do you agree?
2. Give reasons.
3. Name the pioneer species in hydrarch succession

Answer:
1. Yes.

2. In primary succession development of forest climax on a barren land may take about 1,000 years but in secondary succession it takes 50 – 100 years in case of a grassland and about 100 – 200 years for a forest.

3. Phtoplanktons.

Question 2.
Succession on different habitat are different in nature

1. Name the pioneer species on a bare rock.
2. How do they help in establishing the next type of vegetation?
3. Mention the type of climax community that will ultimately get established.

Answer:

1. Lichens are the pioneer species:
2. They absorb water due to their spongy structure and secrete carbonic acid which loosens rock particles and help in weathering of rocks and soil formation; thus, they pave way to some small plants like bryophytes.
3. The climax community will be a forest.

Question 3.
Most of the existing communities are evolved through a series of intermediate stage.

1. Name three plant communites that appear during ecological succession.
2. Elucidate the dynamic changes that happens in a water body.

Answer:
1. three plant communites that appear during ecological succession:

• Pioneer community
• Serai community (transitional community)
• Climax community

2. Phytoplankton stage? Submerged plant stage? Submerged free floating plant stage? Reed swamp stage? Marsh meadow stage? Scrub stage? Forest stage.

Question 4.
If decomposition not occur in nature huge amount of detritus of plants and animals may fill our ecosystems, it is seriously harm to living organisms of our environment

1. Define decomposition
2. Give the steps
3. Decomposers are known as scavengers of earth”. Justify.

Answer:
1. Breaking down of complex organic matter into simple inorganic substance like C02, H20 and Nutrients is called decomposition.

2. Decomposition steps are

• Fragmentation – It is the breaking down of detritus into smaller particle by the detrivores like earthworm.
• Leaching – Precipitation of water soluble or inorganic nutrient into soil horizon.
• Catabolism – It is the degradation of detritus into simple inorganic substances by the action of micro organism.
• Humification – It is the accumulation of dark coloured amorphous substance called humus. Humus serve as the reservoir of nutrients.
• Mineralization – The degradation of humus & release of nutrients from it by microbes is called mineralization.

3. Decomposers split the complex detritus into simple inorganic compounds while doing so they also bring about nutrient cycling. The degradation of detritus into simple organic substances by micro organism involves catabolic process. Without micro organism the earth would have been filled with dead organisms.

Question 5.
In an ecosystem there is unidirectional flow of energy and cyclic flow of matter.

1. Do you agree with the statement.
2. Give reason?
3. Mention the significance of standing crop and standing state in this contest.

Answer:
1. Yes.

2. Energy in an ecosystem flows unidirectionally from producers to different consumers through different tropic level. The constant supply of matter (nutrients like C, N„, P, Ca, etc.) are never lost from the ecosystem. Their constant supply is maintained by nutrient cycling.

3. The mass of living material in a tropic level at a particular time is a standing crop. The amount of nutrients present in a soil at a given time is called standing state.

Question 6.
Robert Constanza and his colleagues put price tags on nature’s life-support services. Price tag of US $ 33 trillion a year

1. What is meant by, ecosystem services? Give example.
2. Which is the most price lagged ecosystem service in nature?

Answer:
1. The product ecosystem process

• Generate fertile soil
• Pollinate crops

2. Soil creation is the most prize tagged ecosystem service.

Question 7.
Decomposition is largely an oxygen requiring process. Rate of decomposition depend upon many factors.

1. What are the factors influence the rate of decomposition
2. Explain it.

Answer:
1. The factors influencing the rate of decomposition are:

• Chemical nature of detritus
• Climatic condition (temperature and soil moistures)

2. Detritus which is rich in N₂ and water soluble substances like sugar decompose quickly than detritus containing lignin and chitin.

Warm and moist environment favour decomposition whereas low temperature and anaerobic condition inhibit decomposition.

Question 8.
The number of individuals in grass land ecosystem is given below.
Grass – 5842,000
Grasshopper – 7,08,000
Frogs – 3,54,000
Snakes – 3

1. Draw a pyramid representing the relationship of the given organisms in terms of number.
2. Give justification for the shape of pyramid.

Answer:
1.

2. The pyramid is an upright one the largest number being producers (grasses) forms the base of the pyramid. The Herbivores or primary consumer at the next level (grass hopper) are second to producers in number.

The third layer is occupied by secondary consumers (Frogs) which are smaller in number compared to the primary consumer. The tertiary consumer (snakes) are the least in number and occupies the top most level. Thus an upright pyramid is obtained.

Question 9.
Food chain ensures unidirectional flow of energy from producerto different levels of consumers. Construct a food chain? Is the flow of energy obey the law of thermodynamics?
Answer:

Yes, the first law of thermodynamics states that energy can neither be created nor destroyed; it can be converted from one form to another. In an ecosystem the plants capture 2-10% of PAR (Photosynthetically active radiation) from the sun.

The solar energy captured by plants flows through different organisms of an ecosystem in the form of food energy. This unidirectional flow of solar energy in accordance with 10% law.

Question 10.
Most of the existing communities are evolved through a series of intermediate stage.

1. Substantiate the above statement with the process involved in the above phenomenon.
2. Elucidate the dynamic changes that happens in a water body.

Answer:
1. Plant succession:
The gradual & predictable change in species composition or communities of a given area is called ecological successions. It occurs due to the change of communities in response to environmental changes. Important features of ecological successions are

• Invasion of a bare area by pioneer community
• sequence of communities that successfully change or modify the particular area called seres
• change in the diversity of species and organism in the successive serai communities
• formation of climax community.

2. Phytoplankton stage → Submerged plant stage → Submerged free floating plant stage → Reed swamp stage → Marsh meadow stage → Scrub stage → Forest stage.

Question 11.
In an ecosystem flow of energy through successive trophic levels decreases, this is very common in aquatic and terrestrial habitat.

1. Write down the first and second thermodynamic laws supports energy flow
2. What do you meant by 10% law

Answer:
1. In first law of thermodynamics energy can be transferred from one state to other while in second law of thermodynamics energy losses in the form of heat.

Question 12.
The average price tag of US is 22 trillion US dollars a year.

1. What does this data indicate?
2. How is it related to GNP?'(Gross National Production)
3. Which is the most price lagged ecosystem service in nature?

Answer:
1. Ecosystem are the base of wide range of economic, environmental and aesthetic goods and services. The products of ecosystem process are named as ecosystem services.

These services are usually taken for granted because they are free. Researches have tried to put prize tags on nature’s life support services in order to understand the values of services provided by nature.

2. Gross national production is the value of human resources and services of a particular country. It is only half the value of ecosystem services.

3. Soil creation is the most prize tagged ecosystem service.

Question 13.
Primary productivity varies in different types of ecosystems.

1. What is meant by primary productivity.
2. Give reason with suitable examples.

Answer:
1. Primary productivity is the amount of biomass or organic matter produced during photosynthesis. The gross primary productivity is the rate of production of organic matter during photosynthesis.

A considerable amount of GPP is utilized by plant in respiration. The gross primary productivity – Respiration losses is the net primary productivity.

2. In some ecosystems producers number and nutrient content are not stable.

Question 14.
In most ecosystems, all the pyramids are upright. But there are exceptions to this generalisation.

1. Give any of the cases where pyramid of number and biomass becomes inverted.
2. What is detritus food chain?

Answer:
1. The pyramid of number in a tree ecosystem is inverted. The primary producer tree is a single unit. The consumers like insects, small birds & large birds are the primary consumers secondary consumers &territory consumers respectively.

Thus the no. of consumer in tree ecosystem is more than that of the producer. The pyramid of biomass in sea is inverted because the biomass of fishes (Consumers) exceeds that of phytoplankton (producer).

2. Food chain starts with detritus called as detritus food chain.

Plus Two Botany Ecosystem NCERT Questions and Answers

Question 1.

1. Plants are called as_____because they fix carbon dioxide.
2. In an ecosystem dominated by trees, the pyramid (of numbers) is_____type.
3. In aquatic eco systems, the limiting factor for the productivity is_______
4. Common ditritivores in our eco system are______
5. The major reservoir of carbon on earth is______

Answer:

1. Producers
2. Upright
3. Availability of sunlight.
4. Earthworm
5. Ocean

Question 2.
Which one of the following has the largest population in a food chain______
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers
Answer:
The decomposers can have the maximum population but they are excluded from food chain, hence the correct answer is – (a) Producers

Question 3.
The second trophic level in a lake is______
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes
Answer:
(b) Zooplankton

Question 4.
What is the percentage of photosyntheticaliy active radiation (PAR) , if incident solar radiation is considered 100%?
(a) 100%
(b) 50%
(c) 1-5%
(d) 2-10%
Answer:
(b) 50%

Question 5.
Give an account for flow of energy in an ecosystem.
Answer:
1. Flow of energy in an ecosystem is unidirectional from producers to consumers.

2. The flow of energy obeys the laws of the thermodynamics 2-10% of radiant energy (50% of which reaches the earth) is photosyntheticaliy active radiation. It travels through different tropic levels from producers in the form of food energy.

The producers convert radiant energy into chemical energy which is stored as biomass. When energy flows from one tropic level to another only 10% of the total energy is transferred, as certain amount of energy is utilized by the organism belonging to a particulartropic level.

Plus Two Botany Ecosystem Multiple Choice Questions and Answers

Question 1.
Which one of the following is not used for construction of ecological pyramids?
(a) Dry weight
(b) Number of individuals
(c) Rate of energy flow
(d) Fresh weight
Answer:
(d) Fresh weight

Question 2.
Which of the following is expected to have the highest value (gm/m2/yr) in a Grassland ecosystem?
(a) Secondary production
(b) Tertiary production
(c) Gross production
(d) Net production
Answer:
(c) Gross production

Question 3.
Which of the following ecosystem types has the highest annual net primary Productivity?
(a) Tropical rain forest
(b) Tropical deciduous forest
(c) Temperate evergreen forest
(d) Temperate deciduous forest
Answer:
(a) Tropical rain forest

Question 4.
An ecosystem, which can be easily damaged but can recover after some time if damaging effect stops, will be having
(a) low stability and high resilience
(b) high stability and low resilience
(c) low stability and low resilience
(d) high stability and high resilience
Answer:
(a) low stability and high resilience

Question 5.
The minimum number of components required for an ecosystem to survive
(a) Producer and primary consumer
(b) Producer and decomposer
(c) primary Consumer and decomposer
(d) primary and secondary Consumer
Answer:
(b) Producer and decomposer

Question 6.
In plant succession, when climax is reached, the net productivity
(a) continues to increase
(b) becomes halved
(c) becomes stable
(d) becomes zero
Answer:
(c) becomes stable

Question 7.
Detrivores are
(a) detritus eating vertebrates
(b) detritus eating fungus
(c) detritus decomposing bacteria
(d) detritus eating invertebrates
Answer:
(d) detritus eating invertebrates

Question 8.
How fig tree is benefited to its pollinator wasp?
(a) Pollens are edible
(b) Wasp lays eggs in fig fruits
(c) Floral petal resembles female to pseudo coupulate
(d) All of these
Answer:
(b) Wasp lays eggs in fig fruits

Question 9.
Which of the following contribute to the carbon cycle?
(a) Photosynthesis
(b) Respiration
(c) Fossil fuel combustion
(d) All of these
Answer:
(d) All of these

Question 10.
Weathering of rocks makes phosphorous available to
(a) Decomposers
(b) Consumers
(c) Producers
(d) All of the above
Answer:
(c) Producers

Question 11.
The 10% law associated with an important function of an ecosystem is
(a) productivity
(b) nutrient cycling
(c) decreases the calorific value in successive trophic levels
(d) increases the calorific value in successive trophic levels.
Answer:
(c) decreases the calorific value in successive trophic levels

Question 12.
In the reductive process, the conversion of nitrogen into ammonia occurs by
(a) nitrosomonas
(b) rhizobium
(c) nitrococcus
(d) pseudomonas
Answer:
(b) rhizobium

Question 13.
The primary productivity is least in
(a) coral reef
(b) grassland
(c) coniferous forest
(d) desert
Answer:
(d) desert

Question 14.
Choose the correct arrangement of plant communities
(a) marsh meadow stage, free floating stage, scrub stage and forest stage
(b) free floating stage, marsh meadow stage, scrub stage and forest stage
(c) marsh meadow stage, free floating stage, scrub stage and forest stage
(d) marsh meadow stage, woodland stage, scrub stage and forest stage
Answer:
(b) free floating stage, marsh meadow stage, scrub stage and forest stage

Question 15.
In the second step of trophic level, the energy storage is primarily associated with
(a) gross primary productivity
(b) net primary productivity
(c) secondary productivity
(d) none of the above
Answer:
(c) secondary productivity

Question 16.
Detritus is the
(a) dead remains of plants only
(b) dead remains of plants and animals
(c) excretory products of animals
(d) both b and c
Answer:
(d) both b and c

Question 17.
The plants efficiency of N₂ absorption is promoted when the nitrogen source available in the form of
(a) NO^3-
(b) NO^2-
(c) NH⁴⁺
(d) none of the above
Answer:
(a) NO^3-

Question 18.
Which one of the following process is associated with oxidation
(a) ammonification
(b) nitrification
(c) denitrification
(d) none of the above
Answer:
(b) nitrification

Question 19.
PAR belongs to the wavelength of
(a) 300-400 A0
(b) 400-700A0
(c) 600-800A0
(d) 700-1000A0
Answer:
(b) 400-700A0

Students can Download Chapter 1 Overview of Computerised Accounting System Questions and Answers, Plus Two Accountancy Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 1 Overview of Computerised Accounting System

Plus Two Accountancy Overview of Computerised Accounting System One Mark Questions and Answers

Question 1.
Accounting Packages are developed on the basis of
(a) Accounting concepts
(b) Accounting conventions
(c) Both Accounting concepts and Conventions
(d) None of the above
Answer:
(c) Both Accounting concepts and Conventions

Question 2.
What type of Software is an Accounting Package?
(a) System Software
(b) Application Software
(c) Utility Software
(d) Basic
Answer:
(b) Application Software

Question 3.
The components of computerised accounting system are
(a) Data, Report, Ledger, software, Hardware
(b) Software, Hardware, People, Procedure, Data
(c) Data, Coding, Procedure, Objective, Output
(d) People, Procedure, Hard ware, software
Answer:
(b) Software, Hardware, People, Procedure, Data

Question 4.
Grouping of Accounts means the classification of data from:
(a) Assets, Capital, and Liabilities
(b) Assets, Capital, Liabilities, Revenues & Expenses
(c) Assets, Owners equity, Revenue & Expenses
(d) Capital, Liabilities, Revenues, & Expenses
Answer:
(b) Assets, Capital, Liabilities, Revenues & Expenses

Question 5.
Codification of Accounts required for the purpose of:
(a) Hierarchical relationship between groups and components
(b) Data processing faster and preparing of final accounts
(c) Keeping data and information secured
(d) None of the above
Answer:
(a) Hierarchical relationship between groups and components

Question 6.
Method of codification should be
(a) Such that it leads to grouping of accounts
(b) An identification mark
(c) Easy to understand and leads to grouping of accounts
(d) None of the above
Answer:
(c) Easy to understand and leads to grouping of accounts

Question 7.
Final account subsystem in Accounting Information System (AIS) deals with
(a) Preparation of budgets
(b) Preparation of Pay Roll
(c) Preparation of Final Accounts
(d) None of the above
Answer:
(c) Preparation of Final Accounts

Question 8.
Pick the odd one out
(a) Password security
(b) Data Audit
(c) Data Bank
(d) Data vault
Answer:
(c) Data Bank

Question 9.
Which among the following is an example of mnemonic codes.
(a) AS03, AS04, AS05
(b) 1925, 1926, 1927, 1928
(c) ACC, ECO, ENG, MAL
(d) 001-100, 101-200, 201-300, 301-400
Answer:
(c) ACC, ECO, ENG, MAL

Question 10.
Which among the following deals with generation of reports that are vital for management decision making?
(a) Costing sub system
(b) Pay Roll Accounting Sub system
(c) Budget Sub System
(d) Management Information System
Answer:
(d) Management Information System

Question 11.
The need of codification is
(a) Easy to process data
(b) Keeping proper records
(c) The generation of block codes
(d) The encryption of data
Answer:
(d) The encryption of data

Question 12.
Choose the correct pair
(a) Cash and Bank sub system – Deals with receipts and payments of cash
(b) Inventory subsystem – deals with recording of sales
(c) Payroll Accounting sub system – deals with the preparation of final accounts
(d) Accounts receivable sub system – deals with expenses.
Answer:
(a) Cash and Bank sub system – Deals with receipts and payments of cash

Plus Two Accountancy Overview of Computerised Accounting System Two Mark Questions and Answers

Question 1.
Name the Five pillers of computerised Accounting System.
Answer:
Procedure, Data, people, Hardware and software

Question 2.
What is computerised accounting?
Answer:
Computerised accounting is the process of recording business transactions and generating financial statements and reports with the help of computer.

Question 3.
List down any Five popular accounting softwares available in India.
Answer:
GNUKhata, Tally, Dac Easy, Tata Ex, Peach Tree

Question 4.
Define Data
Answer:
Data is raw, unorganised facts that need to be processed. Data can be something simple and useless until it is organised.
When data is processed, organised, structured or presented in a given context so as to make it useful, it is called information. A computer is an information processing machine. Computers process data to produce information

Question 5.
Write down any two features of computerised accounting system
Answer:
Features of computerised accounting system:
1. Simple and Integrated:
Computerised accounting system is designed to integrate all the business operations such as sales, finance, purchase, etc.

2. Accuracy and speed:
Computrised Accounting system provides data entry forms for fast and accurate data entry of the transactions.

3. Scalability:
The system can cope easily with the increase in the volume of business transactions. The software can be used for any size and type of the organisation.

Question 6.
What are the account groups of Trading Account under Computerised Accounting System?
Answer:

• Sales account
• Purchase account
• Direct Expenses Account
• Direct Incomes Account

Question 7.
Complete the Table
Name of Account –  Account group in financial Account
Sundry Debtors –  Balance sheet, Asset side

1. Indirect Income __________________________
2. Current Liabilities ________________________
3. Stock in hand ____________________________
4. Sales Account ___________________________

Answer:

1. Profit & Loss Account, Credit side
2. Balances Sheet, Liability side
3. Balance Sheet, Asset side
4. Trading Account, Credit side

Question 8.
What do you mean by sequential code? Give example.
Answer:
Sequential codes:
Here numbers or alphabets are assigned in consecutive order. These codes are applied primarily to source documents such as cheques, invoices, etc.
Example:

Question 9.
What are the basic accounting reports prepared by Computerised Accounting System?
Answer:

• Day Book/ Journals
• Ledges
• Trial balance
• Profit and Loss Account
• Balance Sheet

Plus Two Accountancy Overview of Computerised Accounting System Three Mark Questions and Answers

Question 1.
A computerised accounting software is developed for a company. In Ledger Group, Expenses are divided in to direct expenses and indirect expenses. All the possible expenses of the company are listed under these two sub headings. Appropriate identification numbers are assigned to each such items.

1. Identify the concepts referred to this context
2. Give explanations to each.

Answer:

1. Grouping of Accounts and codification of Accounts
2. Grouping of accounts means classifying the ledger accounts and organizing them under major heads of accounts
   The process of assigning codes to account groups and ledger groups is called codification of accounts.

Question 2.
What are the advantages of computerised Accounting System?
Answer:

• Financial reports can be prepared in time
• Alterations and additions in transactions are easy and gives the changed result in all books of accounts instantly
• It ensures effective control over the system
• Economy in the processing of accounting data
• Confidentiality of data is maintained
• The closing balance of one financial year is automatically carried forward to next financial year

Question 3.
Create an accounting hierarchy for the following ledger account:

• Cash-in-hand
• Provisions for Tax
• Land and Buildings
• Bank Account (Current)
• Trade Investments
• Investments in Govt. Securities
• Deposits with Bank
• Duties and Taxes
• Sundry Debtors

Answer:

• Fixed assets: Land & Building Investment in Govt. Securities
• Current assets: Cash in hand Trade Investments
• Bank: Bank a/c (Current), Deposits with bank
• Sundry debtors: Sundry debtors
• Loans & advances: Provision for Tax
• Duties and Taxes: Duties of Taxes

Question 4.
What are the different types of codes commonly used in CAS?
Answer:
Sequential codes:
Here numbers or alphabets are assigned in consecutive order. These codes are applied primarily to source documents such as cheques, invoices, etc.
Example:

2. Block Codes:
In Block codes, a range of numbers is alloted to a particular account group. Here, numbers within a range follow sequential coding scheme.
Room Numbering System of a Lodge

Code	Account group (group of Legers)
100 – 199	Rooms in First Floor
200 – 299	Rooms in Second Floor
300 – 399	Rooms in third Floor

Coding of Dresses

Code	Account group (group of Legers)
HS400 – HS 499	Half Sleeve Shirts
FS500 – FS 599	Full Sleeve Shirts
MI 600 – MI 699	Mens Inner Wares

3. Mnemonic codes:
A mnemonic code consists of alphabets or abbreviations as symbols to codify an account.
1.

Code	Name of Accounts
1) SLR	Salary Account
2) BOD	Bank Overdraft
3) INV	Inventory

2.

Code	Name of Places
1) TSR	Thrissur
2) TVM	Thiruvananthapuram
3) DLH	Delhi

Question 5.
Distinguish between Data Audit and Data Vault
Answer:
Security Features of Computerised Accounting Software
1. Data Audit:
It enables one to know as to who and what changes have been made in the original data there by helping and fixing the responsibility of the person who has manipulated the data and ensures data integrity.

2. Data Vault:
Software provides additional security through data encryption. Encryption means scrambling the data so as to make its interpretation impossible.

Question 6.
What is the activity sequence of computerised Accounting information processing model?
Answer:

• Collect data
• Organise data
• Communicate Accounting Information

Question 7.
Akhil, your class mate, argues that computerised Accounting System suffers some draw

1. Do you agree with this?
2. Give your justification

Answer:

1. I agree
2. Limitations of CAS.
   • Faster Obsolescence of technology necessitates frequently upgradation in accounting software.
   • Data may be lost or corrupted due to power interruption.
   • Un programmed reports can not be generated
   • Alterations in transactions are easy. This reduces the reliability of accounting work.
   • Work with CAS is expensive.

 

Question 8.
What are the different components of computerised Accounting System?
Answer:
Components of computerised Accounting System:

• Procedure: A logical sequence of actions to perform a task.
• Data: The raw fact for any business operation.
• People: Users of computerised accounting system
• Hardware: The physical components of a computer.
• Software: A set of programmes to do a work.

Plus Two Accountancy Overview of Computerised Accounting System Four Mark Questions and Answers

Question 1.
In the computerised accounting package used by a trading concern, the fixed assets and current assets are combined to form the assets group. The fixed assets are sub divided into tangible and intangible assets.
Show the hierarchy of this ledger group, assuming various assets items.
Answer:

Question 2.
Illustrate with example methodology to develop coding structure.
Answer:
Methodology to Develop Coding Structure:
Let us examine the 15 digit Goods and Services Tax Identification Number (GSTIN). GSTIN is a 15 digit unique code that is assigned to each taxpayer, which will be state-wise and PAN-based.

GSTIN Format or Structure (GSTIN):

From the above details, we can identify that GSTIN is a combination of state code, PAN, number of registration within the state, default digit and check code to detect errors.

Another Example:
Let us examine how to develop a coding structure for students in Thrissur district under DHSE. The first step is to develop a hierarchy of the school system and attributes

Thus we allocate 13 digit code to a student.

Question 3.
What do you mean by AIS? What are the different subsystems of AIS?
Answer:
Accounting Information System (AIS):
Accounting Information System (AIS) and its various subsystems may be implemented through the Computerised Accounting System (CAS). Such system of AIS are described below.

1. Cash and Bank subsystem:
Receipts and payments of cash

2. Sales and Accounts Receivable sub system:
Maintaining of sales and Receivables ledgers.

3. Inventory sub system:
Purchase and sale of goods, Specifying the price, quantity, and date.

4. Purchase and Accounts Payable Sub system:
Maintaining of purchase and payable leadgers.

5. Pav Roll Accounting sub System:
Payment of salaries and wages.

6. Fixed Assets Accounting Sub system:
Purcahses, additions, sale and usage of fixed assets.

7. Expense Accounting sub system:
Various types of expenses.

8. Tax Accounting Sub system:
Deals with GSTIN, Income Tax etc.

9. Final Accounts sub system:
Preparation of final accounts.

10. Costing sub system:
Ascertainment of cost of goods produced.

11. Budget sub system:
Preparation of budgets.

12. Management information sub system (MIS):
Preparation of reports that are vital for management decision making.

Question 4.
What is DATA Encryption? What are the security features of CAS?
Answer:
Security Features of Computerised Accounting Software:
Every accounting software ensures data security, safety, and confidentiality by providing the features like Password Security, Data Audit and Data Vault.

1. Password Security:
Password is the key to allow the access to the system. Computerised accounting system protects the unauthorised persons from accessing to the business data. Only authorised person, who is supplied with the password, can enter to the system.

2. Data Audit:
It enables one to know as to who and what changes have been made in the original data there by helping and fixing the responsibility of the person who has manipulated the data and ensures data integrity.

3. Data Vault:
Software provides additional security through data encryption. Encryption means scrambling the data so as to make its interpretation impossible.

Question 5.
Draw a chart showing different sub systems of Accounting information system.
Answer:
Accounting Information System (AIS):
Accounting Information System (AIS) and its various sub-systems may be implemented through Compterised Accounting System (CAS). Such system of AIS are described below.

1. Cash and Bank subsystem:
Receipts and payments of cash

2. Sales and Accounts Receivable sub system:
Maintaining of sales and Receivables ledgers.

3. Inventory sub system:
Purchase and sale of goods, Specifying the price, quantity, and date.

4. Purchase and Accounts Payable Sub system:
Maintaing of purchase and payable leadgers.

5. Pav Roll Accounting sub System:
Payment of salaries and wages.

6. Fixed Assets Accounting Sub system:
Purcahses, additions, sale and usage of fixed assets.

7. Expense Accounting sub system:
Various types of expenses.

8. Tax Accounting Sub system:
Deals with GSTIN, Income Tax, etc.

9. Final Accounts sub system:
Preparation of final accounts.

10. Costing sub system:
Ascertainment of cost of goods produced.

11. Budget sub system:
Preparation of budgets.

12. Management information sub system (MIS):
Preparation of reports that are vital for management decision making.

Question 6.
Differentiate between Data and Information.
Answer:

Data	Information
1. It is used as input	1. It is the output of processed data
2. Data is the raw material	2. Information is the product
3. It doesn’t carry a meaning	3. It must carry a logical meaning
4. It is an independent value	4. Information depends on data

Students can Download Chapter 9 Structured Query Language Questions and Answers, Plus Two Computer Science Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations

Kerala Plus Two Computer Science Chapter Wise Questions and Answers Chapter 9 Structured Query Language

Plus Two Computer Science Structured Query Language One Mark Questions and Answers

Question 1.
………………. form of SQL is designed for use within general purpose programming languages such as COBOL, C, etc.
Answer:
Embedded SQL.

Question 2.
What is TCL?
Answer:
Transaction Control Language- component of SQL includes commands for specifying transactions.

Question 3.
Data dictionary is a special file in DBMS. What is it used for?
Answer:
Table details are stored in this file.

Question 4.
What does the following statement mean?
Name VARCHAR(30)
Answer:
Field Name can store up to 30 characters. It is a column definition.

Question 5.
Is there any data type available in SQL to store your date of birth information?
Answer:
Yes. DATE data type

Question 6.
Pick the odd one out.
(DEC, NUMBER, INT, DATE)
Answer:
DATE.

Question 7.
How do you ensure that the field ‘name’ will have some value always?
Answer:
using the constraint NOT NULL.

Question 8.
How to set the default value of column District in a table to Thrissur?
Answer:
District VARCHAR(30) DEFAULT ‘Thrissur’

Question 9.
…………… symbol is used as substitution operator in SQL.
Answer:
&

Question 10.
Is there any method to find the strings starting with letter ‘a’ from a field in SQL?
Answer:
Use LIKE operator, LIKE ‘a%’

Question 11.
How to check whether a particular field contains null values or not?
Answer:
Use operator IS NULL

Question 12.
‘ORDER BY’ clause is used for …………
Answer:
Sorting the results of a query by ascending(Asc) or Descending (Desc)

Question 13.
The built-in functions in SQL that return just a single value for a group of rows in a table are called ………..
Answer:
Summary functions or aggregate functions

Question 14.
How to find the number of values in a column in the table?
Answer:
Using the function COUNT()

Question 15.
………………. is the clause in SQL used for categorization.
Answer:
GROUP BY

Question 16.
Thomas wants to remove a table that he were using. How could you help him doing this?
Answer:
Using DROP TABLE command.

Question 17.
Pick the odd one out.
(SELECT, UPDATE, DELETE, DROP TABLE)
Answer:
DROP TABLE

Question 18.
Name the aggregate function that can be used to find the total number of records.
Answer:
COUNT()

Question 19.
Which of the following is an essential clause used with SELECT command?
(GROUP BY, ORDER BY, WHERE, FROM)
Answer:
FROM

Question 20.
Which of the following is not a column constraint?
(CHECK, DISTINCT, UNIQUE, DEFAULT)
Answer:
DISTINCT

Question 21.
Which of the following is a DDL command?
(SELECT, UPDATE, CREATE TABLE, INSERT INTO)
Answer:
CREATE TABLE

Question 22.
What are the logical operators used in SQL?
Answer:
And, Or, Not.

Question 23.
The …………. operator pf SQL is used to match a pattern with the help of %. February 2009
(a) BETWEEN
(b) AND
(c) LIKE
(d) OR
Answer:
(c) LIKE

Question 24.
The structure of a table Book is given below.

BookNo	Integer
Title	Varchar (200)
Author	Varchar(100)
Price	Dec{5, 2)

Write SQL query to Insert an additional column Purchase date of date type to the Books table.
Answer:
Alter table Book add(PurchaseDate Date);

Question 25.
Suppose we want to include a column in a table in which serial numbers are to be stored automatically on adding new records. Which constraint is to be used for that column during table creation?
Answer:
The constraint Autojncrement is used.

Question 26.
Which of the following cannot be used to name a table in SQL? Give the reason.
Answer:
(a) Studnt50
(b) Table
(c) $Employee
(d) Stock_123
Answer:
(b) Table. This is a keyword hence it cannot be used.

Question 27.
Which of the following commands is used to view the structure of a table?
(a) SHOW TABLES
(b) DESC
(C) SELECT
(d) DISPLAY
Answer:
(b) DESC

Question 28.
The command to eliminate the table CUSTOMER from a database is:
(a) REMOVE TABLE CUSTOMER
(b) DROP TABLE CUSTOMER
(c) DELETE TABLE CUSTOMER
(d) UPDATE TABLE CUSTOMER
Answer:
(b) DROP TABLE CUSTOMER

Question 29.
Which SQL command is used to open a database?
(a) OPEN
(b) SHOW
(c) USE
(d) CREATE
Answer:
(c) USE

Question 30.
Which is the keyword used with SELECT command to avoid duplication of rows in the selection?
Answer:
DISTINCT

Question 31.
Pick odd one out and write reason:
(a) WHERE
(b) ORDER BY
(c) UPDATE
(d) GROUP BY
Answer:
UPDATE. It is a command and others are clauses.

Question 32.
Which of the following clause is not used with SELECT command in SQL?
(a) GROUP BY
(b) WHERE
(c) SET
(d) ORDER BY
Answer:
(c) SET. This clause is used with UPDATE.

Question 33.
……………… operator in SQL is used with wild card characters for selection of records.
(a) LIKE
(b) IN
(c) NOT IN
(d) IN and NOT IN
Answer:
(a) LIKE

Plus Two Computer Science Structured Query Language Two Mark Questions and Answers

Question 1.
How is SQL different from other computer high-level languages?
Answer:
SQL means Structured Query Language. It is a relational database language, not a programming language like other high-level languages. It provides facilities to create a table, insert data into a table, retrieve information from a table, modify data in the table, etc.

Question 2.
Distinguish the SQL keywords UNIQUE and DISTINCT.
Answer:
1. Unique – It ensures that no two rows have the same value in a column while storing data. It is used with create command.

2. Distinct – This keyword is used to avoid duplicate values in a column of a table while retrieving data. It is used with select command.

Question 3.
Identify errors in the following SQL statement and rewrite it correctly. Underline the corrections.
CREATE student TABLE (admno PRIMARY KEY, roll no INT, name CHAR);
Answer:
The correct SQL statement is as follows.
CREATE TABLE student( admno INT PRIMARY KEY, roll_no INT, name CHAR(3));

Question 4.
Suppose a column named Fee does not contain any value for some records in the table named STUDENT. Write SQL statements to fill these blanks with 1000.
Answer:
UPDATE STUDENT SET Fee = 1000 WHERE Fee IS NULL;

Question 5.
Identify the errors in the following SQL statement and give reason for the error.
SELECT FROM STUDENT ORDER BY Group WHERE Marks above 50;
Answer:
In this query Group is the keyword hence it cannot be used. The correct query is as follows.
SELECT * FROM STUDENT WHERE Marks > 50 ORDER BY Marks;

Question 6.
Differentiate CHAR and VARCHAR data types of SQL.
Answer:

1. Char – It is used to store fixed number of characters. It is declared as char(size).
2. Varchar – It is used to store characters but it uses only enough memory.

Question 7.
Assume that CUSTOMER is a table with columns Cust_code, Cust_name, Mob_No and Email. Write an SQL statement to add the details of a customer who has no e-mail id.
Answer:
INSERT INTO CUSTOMER VALUES(1001, ‘ALVIS’, 9447024365, NULL);

Question 8.
Find the correct clause from the 2nd column for each SQL command in the 1_st column.

Answer:

Question 9.
Is ALL a keyword in SQL? Explain
Answer:
Yes, ALL retains all the duplicate values of a field

Question 10.
Differentiate LIKE ‘a%’ and LiKE ‘a_’
Answer:
%, it replaces a string but _ replaces only one character at a time.LIKE ‘a%’ retrieve all strings of any length that start with letter ‘a’ while LIKE ‘a_’ retrieve all two letter strings that start with letter ‘a’.

Question 11.
Is multiple sorting possible using ORDER BY clause? Explain
Answer:
Yes, by giving multiple field names separated by comma in the ORDER BY clause.

Question 12.
While inserting records into a table, Raju finds it is not possible to give more than 20 characters in the ‘name’ field. How can you help Raju solve this problem?
Answer:
Using ALTER TABLE command he can modify the width of field so that it can accommodate more than 20 characters.

Question 13.
After executing a query Mohan gets a message like ‘Table Altered’. What would have he done? Give the syntax.
Answer:
He would have used the ALTER TABLE command.
Syntax: ALTER TABLE ADD/MODIFY ();

Question 14.
During discussion one student said that DELETE and DROP TABLE commands are same. Do you agree with that? Justify.
Answer:
No, DROP TABLE removes a table entirely from the database whereas DELETE command deletes only records from an existing table.

Question 15.
1. Pick odd one out.
DROP TABLE, DELETE, ALTER TABLE, CREATE VIEW
2. Justify your answer
Answer:

1. DELETE
2. All others are DDL commands

Question 16.

1. Pick odd one out from the following.
2. Justify your answer.

Answer:

1. Group By
2. Group By is not a Constraint.

Question 17.
Consider the following SQL statements.
DELETE Name.
From Student
Where name = ‘Raju”
Find the error in the SQL if any and correct it.
Answer:
Delete from student where name = ‘Raju’

Question 18.
Consider the following Query in SQL.
From Employee Where branch = ‘Kannur’ Group By Department Having avg (salary) > 7000, Compare the ‘where’ clause and ‘Having’ Clause using the above query.
Answer:
‘where’ clause applies on single rows but Having clause applies on a group.

Question 19.
Some constraints in SQL are called column constraints. Some constraints are called table constraints. How do they differ?
Answer:
Column constraints are specified while defining each column, table constraints are specified once for the entire table at the end of table definition

Question 20.
1. Choose the odd one from the following.
Primary key, Unique, Distinct, Default, Check
2. Justify your choice
Answer:

1. Distinct
2. Distinct is used with select command while others are column constraints of create table command.

Question 21.
Name the most appropriate SQL data type required to store the following data.

1. Name of a student
2. Date of Birth of a student.
3. RollNo. of a student (in the range 1 to 50)
4. Percentage of marks obtained

Answer:

1. Varchar(70)
2. Date
3. Smallint OR Integer Or decimal
4. Dec(5, 2)

Question 22.
1. From the list given below select the names that cannot be used as a table name.
Adm_No, Date, Salary2006, Table, Column_Name, Address.
2. Justify your selection.
Answer:

1. Date, Table
2. There is a data type Date and Table is a keyword used to create a table. So these two are not used.

Question 23.
Classify the following SQL elements into two and give proper title for each category.
NOT NULL, AVG, COUNT, CHECK, SUM, DEFAULT
Answer:

Plus Two Computer Science Structured Query Language Three Mark Questions and Answers

Question 1.
As a part of your school project, you are asked to create a table Student with the fields RollNo, Name, Date of Birth and Score in IT. The constraints required are RollNo. is the primary key. Name cannot be empty.
Answer:
Create table student(RollNo decimal(2) not null primary key, Name varchar(20) not null, DOB date, Score number(2));

Question 2.
A table Employee consists of fields EmployeeNo, Name, Designation and Salary.
Consider that you are forced to give access to this table for an engineer from another company. But for security reasons you need to hide Salary from him. Employee No, Name, Designation, Salary.

1. Name the concept that provides this engineer, a facility to work on this table without viewing salary. Salary view
2. Write SQL query for implementing this SQL query

Answer:

1. Views
2. Create view Empview as select employeeno, Name, Designation from Employee.

Question 3.
Explain the keywords in the following query.
Answer:
SELECT allows to retrieve a subset of rows from the table, DISTINCT avoids duplication of courses from the table STUDENT, FROM is a keyword used to specify the name of the table

Question 4.
A table named student is given below.

Write answers for the questions based on the above table.

1. SQL statement to display the different courses available without duplication.
2. SQL statement to display the Name and Batch of the students whose percentage has a null value.
3. Output of the query select count (percentage) from Student.

Answer:

1. Select distinct batch from Student;
2. Select name, batch from Student where percent is null
3. 5

Question 5.
Once the creation of a table is over, one can perform two changes in the schema of the table. What are they? Give syntax.
Answer:
We can alter the table in two ways.
1. We can add a new column to the existing table using the following
syntax: ALTER TABLE ADD( );

2. We can also change or modify the existing column in terms of type or size using the following
syntax: ALTER TABLEMODIFY( );

Question 6.
Explain how pattern matching can be done in SQL with an example.
Answer:
pattern matching can be done using the operator LIKE while setting the condition with pattern matching. for eg., to display the names of all students whose name begins with letters ‘ma’, we can write the following query, SELECT name FROM STUDENT WHERE name LIKE ‘ma%’; here the character ‘%’ – substitutes any number of characters in the value of the specified column. Another character substitutes only one character of the specified column.

Question 7.
During the discussion of study your friend say that table and view are the same. How can you correct him?
Answer:
Tables and views are different. A view is a single virtual table that is derived from other physically existing tables. When we access a view we actually access the base tables.

We can use all the DML commands with the views but care should be taken as operation actually reflects in the base tables. The advantage of view is that without sparing extra storage space, we can use same table as different virtual tables. It also implements sharing along with privacy.

Question 8.
Find the errors if any of the following code.
Create table emp (name char, RolINo int(20));
Answer:
Here the argument size of data type char of field name is missing. So we can store a character only. The second error is the data type int has no argument. The correct statement is as follows Create table emp (name char(20), RolINo int);

Question 9.
Consider the following variable Declaration in SQL.
a. name char (25)
b. name Varchar (25)

1. Considering the utilisation of memory, which variable declaration is more suitable.
2. Justify your answer

Answer:
1. name varchar (25)
2. Because char data type is fixed length. It allocates maximum memory i.e, here it allocates memory for 25 characters maybe there is a chance of memory wastage. But Varchar allocates only enough memory to store the actual size.

Question 10.
Mr. Dilip wants to construct a table and implement some restrictions on the table.

1. Column can never have empty values.
2. One of the columns must be a key to identify the rows etc.

Can you help him to create that table satisfying the above restrictions with an example
Answer:

1. Use of create table, Not NULL.
2. Primary key Eg: Create table employee(RollNo decimal(3) not null primary key,Name Varchar(70) not null, Design Varchar(30), DOB Date,Salary Dec(7,2));

Question 11.
Write SQL query to construct a table student with fields Reg No, Stud Name, Sex, Course, grade, etc. As per the following conditions

1. Reg No should not be empty and using this column any rows in that table can be identified. Reg. No.
2. Student name should have some value.
3. Default value of sex be Female.
4. Grade should be any of the values: A+, A, B+, B, C+, C, D+, D, E

Answer:
Create table Student(RollNo decimal(3) not null primary key, Name Varchar(70) not null, sex char default ‘Female’,Grade char(2));

Question 12.
Ramu create Table employee with fields empId, empname, Designation, salary using SQL statements. Later he found that data type of emPId is typed as Integer instead of character and missed a field ‘Department’. Can you help him to solve this problem without recreating ‘employee’ table?
Answer:
Alter Table Employee Modify(Empld char(4)); AlterTable Employee Add(Dept char(15));

Question 13.
While creating a table Alvis give “Emp Details” for table name. Is it Possible? Write down the rules for naming a Table.
Answer:
It is not possible because there is a space between Emp and Details. The rules are given below:

1. It must not be a keyword(Keywords are reserved words and have predefined meaning)
2. It must begin with alphabets
3. Digits can be used followed by alphabets
4. Special characters cannot be used except underscore
5. We cannot give the name of another table

Plus Two Computer Science Structured Query Language Five Mark Questions and Answers

Question 1.
Consider the table ITEMS.

a) SELECT ITEMCODE, NAME FROM ITEMS WHERE CATEGORY = ‘Stationery’;
b) SELECT * FROM ITEMS WHERE SALES_ PRICE < UNIT_PRICE;
c) SELECT CATEGORY, COUNT(*) FROM ITEMS GROUP BY CATEGORY;
Answer:

Question 2.
Write SQL queries to SQL Query to
1. Create a table Employee with the fields given below.

2. List the name of all employees whose name’s second letter is ‘a’.
3. List the Name and Designation of employees whose Designation is not ‘Manager’
4. Increase the salary of ail employees by 10 percent.
5. Remove all managers whose salary is less than Rs. 10,000 from the table.
Answer:

1. Create table employee(Name Varchar(70), Desgn Varchar(30), DOB Date, Salary Dec(7,2));
2. Select Name from Employee where Name like
3. Select Name, Desgn from Employee where Desg no’Manager’;
4. Update Employee set Salary = Salary + Salary * .01;
5. Delete from Employee where Desgn = ‘Manager’ and Salary < 10000;

Question 3.
A table Student consists of fields Roll No, Name, Batch and Percent. Write SQL statements to

1. Display RolINo and Name of students whose percentage is Iessthan90 and greater than 70.
2. Display RolINo and Name of all students in science batch whose percentage is more than 90.
3. Display Names of all students in commerce and science batches.
4. Display the average Percent of students in each batch.
5. Display RolINo and Name in the ascending order of Batch and descending order of Percent.

Answer:

1. Select RollNo, Name from Student where percent < 90 and percent > 70;
2. Select RollNo, Name from Student where Batch = ’Science’ and percent > 90;
3. Select Name from Student where batch = ’Science’ Or ’batchCommerce’;
4. Select batch, Avg(percent) from Student group by batch;
5. Select RollNo, Name from Student order by batch, percent desc;

Question 4.
1. Classify the following SQL commands.
Create table, Insert Into, AlterTable, Delete, Up-date, Drop Table, Select.
2. List the features of each category.
Answer:
1. DDL – Create Table, Alter Table, Drop Table.
DML- Insert Into, Delete, Update, Select.

2. DDL – DDL means Data Definition Language. It is used to create the structure of a table, modify the structure of a table and delete the structure of a table. DML -DML means Data Manipulation Language. It is used to insert records into a table, modify the records of a table, delete the records of a table and retrieve the records from a table.

Question 5.
Explain the available database integrity constraints.
Answer:
1. NOT NULL: it specifies that a column can never have null values, i.e., not empty

2. UNIQUE: it ensures that no two rows have same value in the specified column.

3. PRIMARY KEY: it declares a column or a set of columns as the primary key of the table. This constraint makes a column NOT NULL and UNIQUE.

4. DEFAULT: it sets a default value for a column when the user does not enter a value for that column.

5. Auto_increment: This constraint is used to perform auto increment the values in a column. That automatically generates serial numbers. Only one auto-increment column per table is allowed.

Question 6.
Consider a table student with fields Reg No, Stud Name, Sex, Course, total score.
Write SQL queries for the following:
RegNo, Studname, Sex, Course, Total score.

1. Enter a Record
2. List the Detail’s of all students
3. Display Details of the student whose name ends with ‘Kumar’.
4. List all Female students who got more than 50 marks.
5. List all students who are studying either science or in Commerce group.
6. List details of those students who are studying Humanities in the Descending order of their names.

Answer:

1. Insert into Student values (52, ‘JOSE’, ‘Male’, ‘Science’, 500);
2. Select*from Student;
3. Select* from Student where name like ’%Kumar’;
4. Select * from Student where sex=’Female’ and Total >50;
5. Select * from Student where course = ‘science’ or course =‘commerce’;
6. Select* from Student where course-‘Humanities’ order by name desc;

Question 7.
Construct a Table Product with the following fields using SQL.
Product code – Consist of Alphanumeric code.
Product name – Consist of maximum of 30 Alphabets
Unit price – Numeric values
Quantity – Numeric values
Product price – Numeric Values
Write Query for the following:

1. Enter 5 records in the table (not give values for product prices)
2. Calculate product price (unit price × quantity)
3. List all product whose unit price ranging from 10 to 20
4. Calculate total price of all products.

Answer:
Create table Product(ProdCode Varchar(20) not null primary key, ProdName char(30), UPrice decimal(7,2), Qty decimal(6), ProdPrice decimal(7,2));

1. Insert into Product(Product Code,Product Name, Unit Price, Quantity) values (‘101 ’, ‘LUX’, 29.50,500); Similarly insert four more records
2. Update Product set ProdPrice=Qty * UPrice;
3. Select ProdName from Product where UPrice be-tween 10 and 20;
4. Select sum(ProdPrice) from Product;

Question 8.
Mr. Wilson wants to store the details of students. The details consist of different types of data. Explain different data types used in SQL to store data.
Answer:
The different data types are
1. Char (Fixed):
It is declared as char (size). This data type is used to store alphanumeric characters. We have to specify the size. If no size is specified, by default we can store only one character. Eg: name char(20)

2. Variable Character:
It is declared as varchar (size). This data type is also used to store alphanumeric characters. But there is a slight difference. lt allocates only enough memory to store the actual size.
Eg: name varchar(20)

3. Decimal:
It is declared as Dec(size, scale), where size is the number of digits and scale is the maximum number of digits to the right of the decimal point.
Eg: weight dec(3, 2)

4. Integer:
It is declared as int. It does not have any arguments. It takes more memory. Eg: ROllNO int.

5. Small Integer:
It is declared as smallint. It takes less memory ROllNO int.

6. Date:
It is used to store date. Eg: DOB date.

7. Time:
It is used to store time. Eg: Joining_Time Time.

Question 9.
A company wants to create a table to store its employees details. Write SQL Commands for the following :

1. Create a table with EMP table having fields EMPNO primary key varchar(10), Name varchar(20), Salary number(6), Department varchar(3)
2. Insert values to table
3. List all employees whose salary > 10,000 Salary 10,000
4. Display name and salary in the order of name.

Answer:

1. Create table EMP (EMPNO varchar(10) not null primary key, Name varchar(20), Salary decimal(6), Deptvarchar(3));
2. Insert into EMP values (‘1001 ’, ‘ALVIS’, 50000, ‘Sales’);
3. Select * from EMP where salary > 10000;
4. Select name, salary from EMP order by name;

Question 10.
Create a table ‘Savings’ with the following fields. Acc No (Integer), Name (char), age (Integer) and balance (Number) where Acc No is the primary key. Write SQL commands for the following.

1. Insert data in all the fields for 3 records inserted
2. Display the list of account holders in the ascending order Of their names.
3. Display the list of all account holders having age between 20 and 30
4. Display the name and Acc No of customers having a balance > 10 lakhs

Answer:
Create table Savings(Accno decimal(4) not null primary key, name char(2), age decimal(3), Balance decimal(8, 2));

1. Insert into savings values (501, ‘Andrea’, 18,45000)
2. Select * from Savings order by name
3. Select * from Savings where age between 20 and 30
4. Select name.accno from Savings where balance >100000

Question 11.
Which are the components of SQL? How do they help to manage database?
Answer:
The components of SQL are given below.
a. DDL commands ( 3 commands):

1. Create table – Used to create a table.
2. Alter table – Used to modify existing column or add new column to an existing table. There are 2 keywords used ADD and MODIFY.
3. Drop table – Used to remove a table from the memory.

b. DML commands ( 4 commands):

1. Select – Used to select rows from a table. The keyword From is used with this. Where clause is used to specify the condition.
2. Insert – Used to insert new records into a table. So the keyword used is INTO.
3. Delete – Used to delete records in a table.
4. Update – Used to modify the records in a table the keyword used is set.

c. DCL (Data Control Language) commands:

1. Grant – It grants permission to the users to the database
2. Revoke – It withdraws user’s rights given by using Grant command

Students can Download Chapter 10 Vector Algebra Questions and Answers, Plus Two Maths Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Maths Chapter Wise Questions and Answers Chapter 10 Vector Algebra

Plus Two Maths Vector Algebra Three Mark Questions and Answers

Question 1.
Find \(\bar{a}+\bar{b}, \bar{a}-\bar{b}\) and \(\bar{b}+\bar{c}\) using the vectors.
\(\bar{a}\) = 3i + 4j + k, \(\bar{b}\) = 2i – 7 j – 3k and \(\bar{c}\) = 2i + 3j – 9k.
Answer:
\(\bar{a}+\bar{b}\) = 3i + 4j + k + 2i – 7j – 3k = 5i – 3j – 2k
\(\bar{a}-\bar{b}\) = 3i + 4j + k – (2i – 7j -3k) = i + 11j + 4k
\(\bar{b}+\bar{c}\) = 2i – 7j -3k + 2i +3j – 9k
= 4i – 4j – 12k.

Question 2.

1. Find the vector passing through the point A( 1, 2, -3) and B(-1, -2, 1).
2. Find the direction cosines along AB.

Answer:
1. \(\overline{A B}\) = \(\overline{O B}\) – \(\overline{O A}\) = -i – 2j + k – (i + 2j – 3k) = -2i – 4j + 4k.

2. Unit Vector

Direction cosines are \(\frac{-2}{6}\), \(\frac{-4}{6}\), \(\frac{4}{6}\).

Question 3.
Show that the points A, B and C with position vectors \(\bar{a}\) = 3i – 4j – 4k, \(\bar{b}\) = 2i – j + k and \(\bar{c}\) = i – 3j – 5k respectively from the vertices of a right angled triangle.
Answer:

41 = 35 + 6 ⇒ BC² = AB² + CA²
Hence right angled triangle.

Question 4.
Prove that \([\bar{a}+\bar{b} \bar{b}+\bar{c} \bar{c}+\bar{a}]=2[\bar{a} \bar{b} \bar{c}]\).
Answer:
LHS

Note: If \(\bar{a}\), \(\bar{b}\), \(\bar{c}\) are coplanar then so is \([\bar{a}+\bar{b} \bar{b}+\bar{c} \bar{c}+\bar{a}]\).

Question 5.
Consider the vector \(\bar{p}\) = 2i – j + k. Find two vectors \(\bar{q}\) and \(\bar{r}\) such that \(\bar{p}\), \(\bar{q}\) and \(\bar{r}\) are mutually perpendicular.
Answer:
Find a vector \(\bar{q}\) such that \(\bar{p} \cdot \bar{q}\) = 0, for this use any \(\bar{q}\) whose two components are randomly selected. Let \(\bar{q}\) = 2i + 2j + xk
\(\bar{p} \cdot \bar{q}\) = (2i – j + k) . (2i + 2 j + xk) = 0
⇒ 4 – 2 + x = 0 ⇒ x = -2

= 6j + 6k.

Question 6.

Answer:

= i(-12 + 7) – j(-9 – 2) + k(-21 – 8)
= -5i + 11j – 29k

= i(63 + 9) – j(-18 + 6) + k(6 – 14)
= 72i + 12 j – 8k.

Question 7.
If \(\bar{a}\) = 3i + j + 2k,
(i) Find the magnitude of \(\bar{a}\). (1)
(ii) If the projection of \(\bar{a}\) on another vector \(\bar{b}\) is \(\sqrt{14}\), which among the following could be \(\bar{b}\) ? (1)
(a) i + j + k
(b) 6i + 2j + 4k
(c) 3i – j + 2k
(d) 2i + 3j + k
(iii) If \(\bar{a}\) makes an angle 60° with a vector \(\bar{c}\), find the projection of \(\bar{a}\) on \(\bar{c}\) (1)
Answer:

(ii) Since projection of \(\bar{a}\) on another vector \(\bar{b}\) and magnitude of \(\bar{a}\) is \(\sqrt{14}\), then \(\bar{a}\) and \(\bar{b}\) are parallel, (b) 6i + 2j + 4k.

(iii) Projection of \(\bar{a}\) on \(\bar{c}\)
= |\(\bar{a}\)|cos60° = \(\sqrt{14}\) × \(\frac{1}{2}\) = \(\frac{\sqrt{14}}{2}\).

Question 8.
(i) The projection of the vector 2i + 3j + 2k on the vector i + j + k is (1)

(ii) Find the area of a parallelogram whose adjacent sides are the vectors 2i + j + k and 6i – j (2)
Answer:

(ii) Let \(\bar{a}\) = 2i + j + k, \(\bar{b}\) = i – j

= i(0 + 1) – j(0 – 1) + k(-2 – 1 ) = i + j -3k
Area =

Question 9.
(i) The angle between the vectors i + j and j + k is (1)
(a) 60°
(b) 30°
(c) 45°
(d) 90°

Answer:
(i) (a) 60°

Question 10.

Answer:

(ii) Given, \(\bar{a}\) + \(\bar{b}\) + \(\bar{a}\) = \(\bar{0}\), squaring both sides we get

Plus Two Maths Vector Algebra Four Mark Questions and Answers

Question 1.
Let A (2, 3), B (1, 4), C (0, -2) and D (x, y) are vertices of a parallelogram ABCD.

1. Write the position vectors A, B, C and D. (2)
2. Find the value of x and y. (2)

Answer:
1. Position vector of A = 2i + 3 j
Position vector of B = i + 4j
Position vector of C = 0i – 2j
Position vector of D = xi + yj.

2. Since ABCD is a parallelogram, then

(1) ⇒ -i + j = -xi – (y + 2 )j
x = 1, -2 – y = 1 ⇒ y = -3
∴ D is (1, -3).

Question 2.
Find the position vector of a point R which divides the line joining the two points P and Q whose vectors i + 2j – k and -i + j + k in the ratio 2:1

1. internally and
2. externally.

Answer:
\(\overline{O P}\) = i + 2j – k, \(\overline{O Q}\) = -i + j + k
Let R be the position vector of the dividing point,
1.

2.

Question 3.
(i) Choose the correct answer from the bracket. If a unit vector \(\widehat{a}\) makes angles \(\frac{\pi}{4}\) with i and \(\frac{\pi}{3}\) with j and acute angle θ with k. then θ is
(a) \(\frac{\pi}{6}\),
(b) \(\frac{\pi}{4}\),
(c) \(\frac{\pi}{3}\),
(d) \(\frac{\pi}{2}\) (1)
(ii) Find a unit vector \(\widehat{a}\) (1)
(iii) Write down a unit vector in XY plane, making an angle 60°of with the positive direction of x – axis. (2)
Answer:
(i) (c), Since I = cos\(\frac{\pi}{4}\) = \(\frac{1}{\sqrt{2}}\), m = cos\(\frac{\pi}{3}\) = 1/2;
n = cos θ
l² + m² + n² = 1
n² = 1 – (\(\frac{1}{2}\))² – (\(\frac{1}{\sqrt{2}}\))² = 1/4
n = \(\frac{1}{2}\), cosθ = 1/2 , θ = \(\frac{\pi}{3}\).

(ii)

Question 4.
Let the vectors \(\bar{a}\), \(\bar{b}\), \(\bar{c}\) denoted the sides of a triangle ABC.
(i) Prove that (2)

(ii) Find the projection of the vector i + 3j + 7k on the vector 7i – j + 8k (2)
Answer:

(ii) Projection of the vector i + 3j + 7k on the vector 7i – j + 8k

Question 5.
(i) If \(\bar{a}\) and \(\bar{b}\) are any two vectors, then axb is (1)
(a) a vector on the same plane where \(\bar{a}\) and \(\bar{b}\) lie.
(b) ab cosθ, if θ is the angle between them.
(c) a vector parallel to both \(\bar{a}\) and \(\bar{b}\).
(d) a vector perpendicular to both \(\bar{a}\) and \(\bar{b}\).
(ii) Let \(\bar{a}\) = 2i + 4j – 5k, \(\bar{b}\) = i + 2j + 3k. Then find a unit vector perpendicular to both \(\bar{a}\) and \(\bar{b}\). (2)
(iii) Find a vector of magnitude 5 in the direction perpendicular to both \(\bar{a}\) and \(\bar{b}\) (1)
Answer:
(i) (d) a vector perpendicular to both \(\bar{a}\) and \(\bar{b}\).

(ii) \(\bar{a}\) = 2i + 4j-5k, \(\bar{b}\) = i + 2j+3k

= i(12 + 10) – j(6 + 5) + k(4 – 4) = 22i – 11j

Therefore unit vector perpendicular to both \(\bar{a}\) and \(\bar{b}\) is

(iii) 5 × unit vector perpendicular to both \(\bar{a}\) and \(\bar{b}\)

Question 6.
Consider a vector that is inclined at an angle 45° to x-axis and 60° to y-axis

1. Find the dc’s of the vector. (2)
2. Find a unit vector in the direction of the above vector. (1)
3. Find a vector which is of magnitude 10 units in the direction of the above vector. (1)

Answer:
1. Let l, m, n are the direction ratios.
Given that, l = cos 45° = \(\frac{1}{\sqrt{2}}\), m = cos 60° = \(\frac{1}{2}\)
⇒ l² + m² + n² = 1

∴ the dc’s of the vector are \(\frac{1}{\sqrt{2}}\), \(\frac{1}{2}\), \(\frac{1}{2}\)

2. A unit vector in the direction of the above vector is given by li + mj + nk ⇒ \(\frac{1}{\sqrt{2}}\)i + \(\frac{1}{2}\)j + \(\frac{1}{2}\)k.

3. A vector, which is of magnitude 10 units in the direction of the above vector is given by

Question 7.
Consider the point A(2, 1, 1) and B(4, 2, 3)

1. Find the vector \(\overline{A B}\) (1)
2. Find the direction cosines of \(\overline{A B}\) (2)
3. Find the angle made by \(\overline{A B}\) with the positive direction of x-axis. (1)

Answer:
1. \(\overline{A B}\) = 2i + j + 2k

2. |\(\overline{A B}\)| = \(\sqrt{4+1+4}\) = 3
The direction cosines are \(\frac{2}{3}\), \(\frac{1}{3}\), \(\frac{2}{3}\).

3. cos α = \(\frac{2}{3}\) ⇒ α = cos^-1(\(\frac{2}{3}\)).

Question 8.
If i + j + k, 2i + 5j, 3i + 2 j – 3k, i – 6j – k respectively are the position vector of points A, B,C and D. Then

1. Find \(\overline{A B}\) and \(\overline{C D}\). (1)
2. Find the angle between the vectors \(\overline{A B}\) and \(\overline{C D}\). (2)
3. Deduce that \(\overline{A B}\) parallel to \(\overline{C D}\). (1)

Answer:
1.

2.

3. Since the angle between \(\overline{A B}\) and \(\overline{C D}\) is π they are parallel.

Question 9.
Let ABCD be a parallelogram with sides as given in the figure.

1. Find area of the parallelogram. (2)
2. Find the distance between the sides AB and DC. (2)

Answer:
1. Given;
\(\overline{A B}\) = i – 3j + k and \(\overline{A D}\) = i + j + k

2. Let h be the distance between the parallelsides AB and DC. Then ; Area = Base × h _____(2)
Here, Base = |\(\overline{A B}\)|
|i – 3j + k| = \(\sqrt{1+9+1}=\sqrt{11}\)
From (1) and (2)

Question 10.
Consider \(\bar{a}\) = i + 2j – 3k, \(\bar{b}\) = 3i – j + 2k, \(\bar{c}\) = 11i + 2j

1. Find \(\bar{a}\) + \(\bar{b}\) and \(\bar{a}\).\(\bar{b}\) (2)
2. Find the unit vector in the direction of \(\bar{a}\) + \(\bar{b}\). (1)
3. Show that \(\bar{a}\) + \(\bar{b}\) and \(\bar{a}\) – \(\bar{b}\) are orthogonal. (1)

Answer:

(ii) Unit vector in the direction of

(iii) We have,

Therefore, they are orthogonal.

Question 11.
Let A (1, -1, 4), B ( 2, 1, 2 ) and C (1, -2, -3 )

1. Find \(\overline{A B}\). (1)
2. Find the angle between \(\overline{A B}\) and \(\overline{A C}\).(2)
3. Find the area of the parallelogram formed by \(\overline{A B}\) and \(\overline{A C}\) as adjacent sides. (1)

Answer:
1. \(\overline{A B}\) = P.v of B – P.v of A
= 2 i + j + 2 k – (i – j + 4k) = i + 2 j – 2k

2. \(\overline{A C}\) = P.v of C – P.v of A
= i – 2 j – 3 k -(i – j + 4k) = – j – 7k
Let A be the angle between \(\overline{A B}\) and \(\overline{A C}\)

3.

Area of the parallelogram

Plus Two Maths Vector Algebra Six Mark Questions and Answers

Question 1.
Using this figure answer the following questions.

1. Find \(\overline{O A}\), \(\overline{O B}\), \(\overline{O C}\) (2)
2. Find \(\overline{O D}\) (2)
3. Find the coordinate of the vertex D. (2)

Answer:
1. \(\overline{O A}\) = (3 – 1)i + (-1 – 2)j + (7 – 3)k = 2i – 3j + 4k
\(\overline{O B}\) = (2 – 1)i + (4 – 2)j +(2 – 3)k = i + 2j – k
\(\overline{O C}\) = (4 – 1)i + (1 – 2 )j + (5 – 3 )k = 3i – j + 2 k.

2. From the figure,

3. Let the vertex of D be (x , y , z),
Then, \(\overline{O D}\) = (x – 1)i + (y – 2)j + (z – 3)k.
But we have,
\(\overline{O D}\) = 6i – 2j + 5k = (x – 1)i + (y – 2)j +(z – 3)k
x – 1 = 6 ⇒ x = 7, y – 2 = -2 ⇒ y = 0, z – 3 = 5 ⇒ z = 8.

Question 2.
OABCDEFG is a cube with edges of length 8 units and axes as shown. L, M, N are midpoints of the edges FG, GD, GB respectively.

1. Find p.v’s of F, B,D and G. (1)
2. Show that the angle between the main diagonals is θ = cos^-1\(\left(\frac{1}{3}\right)\). (2)
3. Find the p.v’s of L, M, N. (1)
4. Show that \(\overline{L M}+\overline{M N}+\overline{N L}=0\). (1)

Answer:
1. \(\overline{O F}\) = 8 j + 8k, \(\overline{O B}\) = 8i + 8k, \(\overline{O D}\) = 8i + 8k, \(\overline{O G}\) = 8i + 8j + 8k.

2. Consider the main diagonals \(\overline{O G}\) and \(\overline{E B}\)

3. P.V of L = \(\overline{O L}\) = 4i + 8j + 8k
P.V of M = \(\overline{O M}\) = 8i + 8j + 4k
P.V of N = \(\overline{O N}\) = 8i + 4j + 8k

4.

Question 3.
Using the figure answer the following questions

1. Evaluate \(\overline{A B}\).\(\overline{A C}\) (2)
2. Find \(\overline{A D}\) . (2)
3. Find the coordinates of D.

Answer:
1. \(\overline{A B}\) = p.v of B – p.v of A= -4i + 0j + 3k
\(\overline{A C}\) = p.v of C – p.v of A = 0i – 4 j + 4k
\(\overline{A B}\).\(\overline{A C}\) = -4 × 0 + 0 × -4 + 3 × 4 = 12

2.

3. Let the coordinate of D be (x, y ,z)
⇒ \(\overline{A D}\) = (x – 3)i + (y – 2)j + (z – 1)k,

Question 4.
Consider the Parallelogram ABCD

1. Find \(\overline{A B}\) and \(\overline{A D}\) (1)
2. Find the area of the parallelogram ABCD. (1)
3. Find \(\overline{A C}\). (2)
4. Find co-ordinate of C. (2)

Answer:
1. \(\overline{A B}\) = p.v of B – p. v of A
= 3i + 5j + 8k – (i + 2j + k) = 2i + 3j + 7k
\(\overline{A D}\) = p.v of D – p. v of A
= i + 3j + 2k – (i + 2j + k)= 0i + j + k.

2.

3. By triangle inequality;

4. Let the co-ordinate of C be (x, y, z)
Then, \(\overline{A C}\) = (x – 1)i + (y – 2)j + (z – 1)k = 2i + 4j + 8k
x – 1 = 2 ⇒ x = 3, y – 2 = 4 ⇒ y = 6,
z – 1 = 8 ⇒ z = 9
Co-ordinate of C is (3, 6, 9).

Question 5.
Consider the following quadrilateral ABCD in which P, Q, R, S are the midpoints of the sides.

1. Find \(\overline{P Q}\) and \(\overline{S R}\) in terms of \(\overline{A C}\) (2)
2. Show that PQRS is a parallelogram. (2)
3. If \(\bar{a}\) is any vector, prove that (2)

Answer:
1. Using triangle law of addition, we get

2. From the above explanation we have,

and parallel. Similarly, |\(\overline{S P}\)| = |\(\overline{R Q}\)|
Therefore, PQRS is a parallelogram.

3. Let \(\bar{a}\) = a₁ i + a₂ j + a₃ k