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Reviewing Kerala Syllabus Plus Two Chemistry Previous Year Question Papers and Answers Pdf Board Model Paper 2019 helps in understanding answer patterns.

Kerala Plus Two Chemistry Board Model Paper 2019 with Answers

Time: 2 Hours
Maximum: 60 Scores

Questions from 1-7 carry one score each, answer all the questions. (7 × 1 = 7)

Question 1.
Which of the following is an example of an ideal solution?
(a) Phenol + Aniline
(b) Ethanol + Acetone
(c) Acetone + Chloroform
(d) Benzene + Toluene
Answer:
(d) Benzene + Toluene

Question 2.
Identify the ore of zinc from the following:
(a) Siderite
(b) Malachite
(c) Haematite
(d) Calamine
Answer:
(d) Calamine

Question 3.
Write the ‘Spin-only’ formula used to calculate the magnetic moment.
Answer:
\(\mu=\sqrt{n(n+2)}\)
n = no. of unpaired electrons.

Question 4.
Give one example for a hexadentate ligand.
Answer:
EDTA

Question 5.
What is the chemical name of aspirin?
Answer:
Acetyl Salicylic Acid

Question 6.
Which synthetic zeolite is used for converting alcohol to gasoline?
Answer:
ZSM-5

Question 7.
What are the main constituents of Dettol?
Answer:
Chloroxylenol and Terpinol

Questions 8-20 carry two points each. Answer any ten questions. (10 × 2 = 20)

Question 8.
Write any two differences between crystalline and amorphous solids.
Answer:

Cystalline Substances	Amorphous Substances
1. Definite shape.	1. Irregular shape.
2. Sharp melting point.	2. Melting point is in a range.
3. Long range order.	3. Short range order.
4. Anisotropic.	4. Isotropic.

Question 9.
A compound with cubic structure is made of elements X and Y. X atoms are at the corners of the cube and Y atoms are at the body centre. Write the simplest formula of the compound.
Answer:
No. of X atoms (corners) = \(\frac{1}{8}\) × 8 = 1
No. of Y atoms (body centre) = 1
X : Y = 1 : 1 i.e. XY

Question 10.
When a zinc electrode (Zn (s)/Zn²⁺ (1m)) combines with SHE at 298 K and forms a galvanic cell. \(E_{\text {cell }}^0\) is found to be, 0.76 V. Write cell representation of the cell and calculate the standard electrode potential of the zinc electrode.
Answer:
When combined with SHE, the zinc electrode acts as an oxidation half cell (anode), while SHE acts as a reduction half cell or cathode.
\(E_{\text {cell }}^0\) = 0 – 0.76 = -0.76V

Question 11.
How many coulombs of electricity are required to produce 40 g of Al from Al3+ solution?
Answer:
Al³⁺ + 3e^– → Al
3 Faraday is needed to deposit 27g aluminum.
3F → 27 g Al
\(\frac{3F}{27}\) → 1 g Al
\(\frac{3F}{27}\) × 40 → 40 g Al
(\(\frac{3}{27}\) × 40) Faraday → 40 g Al
4.44 F → 40 g Al

Question 12.
What is chemical kinetics? Give any importance to it?
Answer:
Chemical kinetics is the branch of chemistry that deals with the rate of chemical reaction, factors affecting the rate, and the mechanism of a reaction.
Applications:

• To find how fast a medicine works.
• Speed of a reaction.
• Formation of ozone layer.

Question 13.
Explain homogeneous catalysis with one example.
Answer:
The catalysis in which both the reactants and the catalyst are in the same phase is called homogeneous catalysis.

Question 14.
Explain Mond Process.
Answer:
Mond Process: In this process, nickel is heated in a stream of carbon monoxide forming a volatile complex, nickel tetracarbonyl.
It is then decomposed to Ni and CO by heating at very high temperature.

Question 15.
PH₃ has a lower boiling point than NH₃, why?
Answer:
Due to the presence of strong hydrogen bonds, NH₃ has a high boiling point. But in PH₃ no hydrogen bond is present so its boiling point is low.

Question 16.
Silver atom has filled ‘d’ orbitals (4d¹⁰) in its ground state. Why is it considered a transition metal?
Answer:
Because its +1 and +2 oxidation state has incomplete d subshell. So it is a transition element.

Question 17.
Actinoid contraction is greater than Lanthanoid contraction. Account for it?
Answer:
The 5f electrons of actinoids are more effectively shielded from nuclear Charge than the 4f in lanthanoids.

Question 18.
Draw the cis and trans isomers of [CoCl₂(en₂]⁺?
Answer:

Question 19.
What is ‘DIBAL-H’? Give the importance of it?
Answer:
Diisobutylaluminium hydride (DIBAL – H) is a reducing agent.
Use: It can selectively reduce CN group or ester group without affecting double or triple bond.

Question 20.
Write the correct order of basic character of the following amines is (a) Gas phase and (b) in aqueous solution.
Answer:
In gas phase basicity is in the order 3° > 2° > 1°
(CH₃)₃N > (CH₃)₂NH > CH₃NH₂
In aqueous solution basicity is in the order 2° > 1 ° > 3°
(CH₃)₂NH > CH₃NH₂ > (CH₃)₃N

Questions from 21-29 carry three points each. Answer any seven questions. (7 × 3 = 21)

Question 21.
Write any three applications of Henry’s law.
Answer:

• Formation of bends as the scuba divers reach the Surface of the sea.
• Anoxia: At high altitudes, the amount of oxygen in the air is low, which creates a headache and is known as Anoxia.
• To increase the solubility of CO₂ in water, soda water is kept under high pressure in sealed vessels.

Question 22.
Activity and selectivity are the two important terms used in catalysis. Explain these terms with suitable examples.
Answer:
Activity: Catalyst can increase the rate of a chemical reaction.

The reaction takes place only in the presence of platinum.
Selectivity: A catalyst can direct a chemical reaction to a particular product.

Question 23.
(a) Write the formula for the following coordination compounds.
(i) Tetra ammine aquachlorido cobalt (III) chloride
(ii) Potassium tetrahydroxidozincate (II)
(b) Write the IUPAC names of the given coordination compound K[Co(SCN)₄]
Answer:
(a) [CO(NH₃)₄(H₂O)Cl]Cl₂
(b) K₂[Zn(OH)₄]
(c) Potassium Thiocyantatocobaltate (II)

Question 24.
Explain the S_N1 mechanism with a suitable example.
Answer:
Step I: Formation of a carbocation

Step II: Attack of a nucleophile

Question 25.
Complete the following.

Answer:

Question 26.
Write any three methods for the preparation of ethanamine (C₂H₅-NH₂).
Answer:
1. Reduction of nitriles

2. Reduction of Amides

3. Hoffmann bromamide reaction.
CH₃CH₂CONH₂ + Br₂ + NaOH → CH₃CH₂NH₂ + Na₂CO₃ + 2H₂O + 2NaBr

Question 27.
Write the important structural and functional differences between DNA and RNA.
Answer:

DNA	RNA
Double stranded.	Single stranded.
Nucleic acid present is deoxyribose.	Nucleic acid present is deoxyribose.
Bases present are adenine, Thymine, cytosine, guanine.	Bases present are Adenine, Uracil Cytosine and guanine.

Question 28.
(a) Name two synthetic polypeptide fibres.
(b) Indicate the monomers in each.
Answer:
(a) Nylon 6,6 – monomers – hexamethylenediamine and adipic acid
(b) Nylon 6 – caprolactum

Question 29.
Explain the therapeutic action of the following:
(a) Antacids
(b) Analgesics
(c) Antibiotics
Answer:
(a) Antacid: Used to reduce acidity in the stomach.
(b) Analgesic: to reduce pain or painkillers.
(c) Antibiotics: are drugs which kill or prevent the growth of microorganisms which are prepared from other microorganisms.

Questions 30-33 carry fourscore each. Answer any three questions. (3 × 4 = 12)

Question 30.
(a) Explain pseudo first order reaction with an example.
(b) A first order reaction has a rate constant 1.15 × 10^-3 S^-1. How long will 5g of this reactant take to reduce to 3g?
Answer:
(a) Reactions which appear to be higher order but follow first order kinetics are called pseudo first order reactions.
eg: CH₃COOC₂H₅ + H₂O → CH₃COOH + C₂H₅OH

Question 31.
(a) Why does ozone act as a powerful oxidising agent?
(b) How is O₃ estimated quantitatively?
Answer:
(a) Because ozone on decomposition gives nascent oxygen, which is a powerful oxidizing agent.
O₃ → O₂ + [O]
(b) When ozone and potassium iodide react, iodine is liberated. Now this iodide is titrated against a standard solution of sodium thiosulphate using starch as indicator.
2I + H₂O + O₃ → 2OH + I₂ + O₂
2Na₂S₂O₃ + I₂ → Na₂S₄O₆ + 2NaCl

Question 32.
(a) Explain the reason for the less reactivity of chlorobenzene than alkyl chloride?
(b) Identify the major product formed by the reaction of 2-bromobutane with alcoholic KOH. Give reason for it.
Answer:
(a) 1. Due to resonance effect, chlorobenzene develops a partial double bond character to the C-Cl bond which is difficult to break.
2. Instability of phenyl cation
3. Greater S character in sp² hybridised c-atom, which is more electronegative. Thus the bond in chlorobenzene becomes shorter and difficult to break.
4. Electron rich benzene ring

According to Saytzeft rule, more symmetric products are favoured.

Question 33.
Explain the following reactions.
(a) Aldol condensation
(b) HVZ reaction
Answer:
(a) Aldehydes or ketones with α hydrogen atom undergo condensation in the presence of dil. alkali to form aldols. (β hydroxy aldehyde). This reaction is known as aldol condensation.

(b) HVZ Reaction
Carboxylic acid with α hydrogen is heated with chlorine or bromine in the presence of red phosphorous to give α halo carboxylic acid.

Reviewing Kerala Syllabus Plus Two Computer Science Previous Year Question Papers and Answers Pdf SAY 2019 helps in understanding answer patterns.

Kerala Plus Two Computer Science Previous Year Question Paper SAY 2019

Time: 2 Hours
Total Score: 60 Marks

Answer any 5 questions from 1 to 6. Each carries 1 score. (5 × 1 = 5)

Question 1.
Which among the following is an object – oriented programming language?
a) Pascal
b) FORTRAN
c) C++
d) C
Answer:
c) C++

Question 2.
Which among the following is known as push operation?
a) Inserting a new data item into a stack.
b) Deleting an element from top of a sack.
c) Inserting an element in a queue.
d) Inserting an element in a linked list.
Answer:
a) lnserting a new data item to the stack

Question 3.
Which among the following does not belong to the group?
a) Drupal
b) Joomla
c) File Zilla
d) WordPress
Answer:
c) File Zilla

Question 4.
Write full form of SMTP.
Answer:
Simple Mail Transfer Protocol

Question 5.
A web page can contain various links that direct to other web pages or specific parts of same web page. In HTML links are created using <A> tag. The attribute of <A>tag which specifies link destination is
Answer:
href

Question 6.
The year in which IT act came into existence in India is …………………..
Answer:
2000

Answer any 9 questions from 7 to 18. Each carries 2 scores. (9 × 2 = 18)

Question 7.
Structure combines different types of data under a single unit.
Write a structure definition in C++ which includes student details admission number, name, age and weight.
Answer:
struct student{
int admno;
char name[25];
int age;
float weight;
};

Question 8.
Which are the operations that facilitates dynamic memory allocation in C++? What are their functions?
Answer:
New is used to allocate memory during execution of the program. Delete is used to de-allocate the memory during run time.

Question 9.
What is reusability? How is reusability possible through inheritance?
Answer:
Once a class is defined, it can be used in other programs easily, this is called reusability. Inheritance allows the addition of more features to an existing class without modifying it. One can derive a new class from an existing one and add new features to it.

Question 10.
List any two applications of stack.
Answer:
Reversing a string, creating polish strings.

Question 11.
The user name and password of an e-mail account has to be sent securely over the Internet?
(a) Name the technology used to send data to the server securely.
(b) How does this technology support secure data communication?
Answer:
a) https(Hypertext transfer protocol secure)

b) It works using secure sockets layer, which provides a standard security technology for establishing an encrypted connection between computers on net.

Question 12.
How does browser execute JavaScript code?
Answer:
Every browser has a JavaScript engine. If the code snippet contains JavaScript code, it is passed to the JavaScript engine for processing, the engine executes the code. If there is no script then it processes without the help of script engine. Hence an HTML file without JavaScript is faster than with JavaScript code.

Question 13.
Write the keyword used to declare variables in JavaScript.
List different data types in JavaScript.
Answer:
In JavaScript, variables can be declared by using the keyword var.
Ex: var n;
The three basic data types are Number, String, Boolean.

Question 14.
Cardinality of two relations R₁ and R₂ are 10 and 8 respectively. They are union compatible.
a) What is the maximum possible cardinality of R₁∪R₂?
b) What will be the minimum cardinality of R₁∩R₂?
Answer:
a) 80
b) 0

Question 15.
What is primary key? How does it differ from alternate key?
Answer:
It is a set of one or more attributes used to uniquely identify a row in a relation. But a foreign key is a candidate key other than the primary key.

Question 16.
What are the methods of writing comments in PHP?
Answer:
There are two ways to write comments in PHP.

1. Single line comment (//)- The text after // is treated as comment.
2. Multi line comment- It starts with I* and ends with /*. The text enclosed between this is treated as comments.

Question 17.
Write any two advantages of parallel computing compared to serial computing.
Answer:

Serial computing	Parallel computing
A single processor is used	Multiple processors are used with shared memory
A problem is divided into a series of instructions	A problem is divided into smaller ones that can be solved simultaneously
Instructions executed sequentially	Instructions executed simultaneously
One instruction is executed on a single processor at any moment	More than one instruction is executed on multiple processors at any moment of time.

Question 18.
What is e-Governance? List any two challenges to e-Governance.
Answer:
The integration of computers and communication technology for the benefit of Government functions to the public is termed as E-Governance. By this Govt can serve the citizen in a convenient, efficient and transparent manner.

Challenges-

• Due to lack of e-Literacy, there is a difficulty to access the service of E-Governance
• High Security measures are required because of possibility of cyber attack.
• Implementation and maintenance requires huge amount and planning.

Answer any 9 questions from 19 to 30. Each carries 3 scores. (9 × 3 = 27)

Question 19.
Write differences between array and structure. (At least three differences.)
Answer:

Structure	Array
Differences 1. It is a user defined data type	Predefined data type
2. It is a collection of different types of logically related data under one name.	Collection of data elements of same data type having a common name.
3. Elements referenced using dot operator (.)	Elements reference using its subscripts (position value)
4. When an element of a structure becomes another structure nested structure and complex structures are formed.	When an element of another becomes another array, multidimensional arrays are formed.
5. Structure contains array as its elements	Array of structure can be formed.

Question 20.
Write any three advantages of object oriented programming compared to procedural programming.
Answer:
Advantages of OOP are

• OOP allows modularity
• It is good for defining abstract data types
• It allows data abstraction
• fallows code reusability
• ft supports to create new data type.

Question 21.
Write short notes about any six operations on data structures.
Answer:
Operations on data structures
a) Traversing: Accessing or visiting or reading all elements of a data structure is called Traversal.
b) Searching: Searching is the process of finding elements in a data structure
c) Inserting: It is the process of adding new data at particular location is called insertion.
d) Deleting: It is the process of removing a particular element from the data structure
e) Sorting: Arranging elements in a particular orderfascending or descending) is called sorting. Examples are bubble sort and selection sort.
f) Merging: This is the process of combining two sorted data structure and form a new one.

Question 22.
What is a data centre? What are the basic facilities required to set up a data centre?
Answer:
A data centre is a place where huge amount of data is stored by the organisations. The main objective of data centers are storing, processing, dispensing data to the clients. A data center requires huge memory, uninterrupted power supply, cooling system, high speed internet and high security.

Question 23.
(a) Which HTML tag is used to partition the browser window?
(b) Write HTML code to partition the browser window into two equal vertical partitions and load two
HTML documents sample 1.html and sample2.html in them.
Answer:
a) <frameset>

b) <framesetcols=”50%,*”>
<framesrc=”sample1.htmr>
<framesrc=”sample2.htmr>
</frameset>

Question 24.
Write built-in functions or properties in JavaScript to perform the following:
a) To display a message on the screen.
b) To check whether a value is number or not.
c) To get upper case form of a string.
d) To get lower case form of a string.
e) To get character at a particular position in a string.
f) To get number of characters in a string.
Answer:
a) alert()
b) isNaN()
c) toUpperCase()
d) toLoweCase()
e) charAt()
f) x.length();

Question 25.
What is web hosting? List different types of web hosting. What are the factors, to be considered while choosing web hosting?
Answer:
Buying or renting storage space to store website in a web server and provide sen/ice to all the computers connected to the internet. This is called web hosting.
Types of web hosting

1. Shared hosting
2. Dedicated hosting
3. Virtual Private Server

Following factors to be considered while choosing web hosting
a) Buying sufficient amount of memory space for storing our website files.
b) If web page contain programming contents supporting technology must be consider.
c) Based upon the programs select Windows or Linux hosting.

Question 26.
List advantages (any six) of database management system compared to traditional file management system.
Answer:
1) Data Redundancy: Duplication of data is known as redundancy, i.e., the same data may be repeated in many files. It leads to higher storage and access cost. So data redundancy should be eliminated

2) Inconsistency can be avoided: If data redundancy exist, it may lead to data inconsistency. If redundancy is removed then inconsistency can be avoided.

3) Data can be shared: If the computers are connected to a network, the data stored in the database can be shared among several users or programs.

4) Standards can be enforced: There is a standard BIS (Bureau of Indian Standards) in the field of Gold and ISBN (International Standard Book Number) in the field of publication. Similarly here is also some standards like ANSI(American National Standards Institute), ISO (International Organization for standardization), etc.. For example a filed “Name” should have 40 characters is a standard.

5) Security restrictions can be applied: The database is of great value to a company or organization. Data security means protection of data against accidental or intentional disclosure or unauthorized destruction or modification by unauthorized persons.

6) Integrity can be maintained: It ensures that the data entered in the database is correct. The data may contain in fcorrect information for example a date of birth can be 30/30/2001. To avoid this DBMS defines integrity check.

Question 27.
Write SQL commands for the following:
a) To remove a column from a table.
b) To remove a row from a table.
c) To modify data in a table.
Answer:
a) alter table <table name> drop <column name>;
b) delete from <tablename> where <condition>;
c) update <tablename> set <column name>=<new
value> [where <condition>];

Question 28.
What are the two methods of sending information from a form to web server? How do these two methods differ? (Write any four differences)
Answer:

Get	Post
1. Faster	Slower
2. To send small volume of data	To send large volume of data
3. Less secure	More secure
4. Data visible during submission	Data not visible during submission

Question 29.
Write advantages of cluster computing.
Answer:
Cluster means groups. Here a group of Internet connected computers, storage devices, etc are linked together and work like a single computer. It provides computational power through parallel processing. Its cost is less and used for scientific applications.

Advantages

• Price performance ratio: The performance is high and the cost is less.
• Availability: If one group of system fails the other group will do the work.
• Scalability: Computers can be easily added according to the work load increases.

Question 30.
What is e-Business? What are the challenges to e-Business?
Answer:
E business(electronic Business): Providing services or running business through internet is called E business.
Advantages of ebusiness:

• It overcomes geographical limitations
• It reduces the operational cost
• It minimizes the time and cost
• It remains open all the time
• We can locate the product faster from a wider range of choices

Challenges to E business

• Peoples are unaware of IT applications and its uses
• Most peoples don’t have plastic money(credit / debit card) and net banking
• It requires high security measurements otherwise you may lose money
• We can’t touch or smell products through online
• Some companies may not have proper Goods delivery service

Useful e Business websites
Address of website – Purpose / Service
www.irctc.in – Web site of Indian Railway and Tourism Corporation Ltd. to reserve and cancel train tickets and room booking
www.amazon.com – Us based marketing company headquarters in Washington
www.ebay.in – Largest online shopping site in India
www.licindia.com – Website of Life Insurance Corporation of India
www.airindia.com – Website of Air India to book / cancel air tickets
www.makemytrip.com – website for reserving and canceling tickets for journey and room booking www.keralartc.com – Website of KSRTC to book bus tickets

Answer any 2 questions from 31 to 33. Each carries 5 scores. (2 × 5 = 10)

Question 31.
(a) An HTML documents begins with <HTML> tag.
What are the attributes of <HTML>tag? Specify the values these attributes can take.
(b) Explain basic structure of an HTML document with a simple example.
Answer:
a) Attributes of <HTML>tag

1. Dir-: It specifies the direction of text displayed on the webpage, values are Itr and rtl.
2. Lang-: It specifies the language, values are En(English),Hi(Hindi),Ar(arabic), etc..

b) HTML page has a well defined structure. The main sections of HTML document are given below. <HTML>_____</HTML>
The entire HTML document is bounded with <HTML> and </HTML>
<Head> __________ </Head> This defines the head section. The head section,includes information such as document title, general style definition etc.
<Title>_________ </Title> This encloses a Title.
Title is given in head section. Text given in

<TITLE> _________ </TITLE>will displayed in the Title Bar.
<Body></Body>. Content of the document is written within <BODY> and </BODY>
Eg. <HTML>
<Head>
<Title>First Page</Title>
</Head>
<Body>
Hello
</BODY>
</HTML>

Question 32.
Explain values (any five) that can be given to type attribute of <INPUT>tag.
Answer:
The ‘type’ attribute of <INPUT> tag is used to create different control. The main values of type attribute is given below.

1. Text: Creates a single line Text Box.
   Eg. <INPUT Type= “Text”>
2. Password: creates a password box in which characters are displayed by symbols like asterisk(*)
   Eg. <INPUT Type= “Password”>
3. Check Box: Creates a check box.
   Eg. <INPUTType = “Check Box”>
4. Radio: Creates option button (Radio Button)
   Eg. <INPUT Type= “Radio” Name=”sex” Value- ”M”>Male.
5. Reset: Creates reset button. It is used to clear all the data entered
   Eg. <INPUT Type= “Reset”>

Question 33.
Consider the following table CUSTOMER.

AccNo.	Name	Branch	Amount
1001	APPU	CALICUT	40000
1002.	ARUN	KANNUR	20000
1003	VARUN	CALICUT	10000
1004	THARUN	KOTTAYAM	30000
1005	VARUN	KANNUR	20000

Write output of the following SQL series:
a) Select Name from Customer where Amount>20000;
b) Select Avg(Amount) from Customer where Branch = ‘CALICUT’;
c) Select Name from Customer where Name like ‘A%’.
Write SQL queries for the following:
d) To rename the Table Customer as Customer2020.
e) To delete record with AccNo. 1003 from the table Customer2020.
Answer:
a)
Name
APPU
THARUN

b)
avg(Amount)
25000

c)
Name
APPU
ARUN

d)
alter table Customer rename to Customer2020;
b) delete from Customer2020 where AccNo= 1003

Reviewing Kerala Syllabus Plus Two Chemistry Previous Year Question Papers and Answers Pdf Board Model Paper 2021 helps in understanding answer patterns.

Kerala Plus Two Chemistry Board Model Paper 2021 with Answers

Time: 2 Hours
Maximum: 60 Scores

Answer the following questions from 1 to 40 up to a maximum score of 60.
Questions from 1 to 11 carry 2 scores each. (11 × 2 = 22)

Question 1.
Calculate the number of particles present per unit cell in the cubic lattice shown below:

Answer:
bcc
Particles at the corner contribute \(\frac{1}{8}\).
Particles at 8 corners contribute
∴ \(\frac{1}{8}\) × 8 = 1
Particle at the centre contributes one as a whole.
∴ Total no. of particels = 1 + 1 = 2

Question 2.
With the help of a diagram, represent the arrangement of valence band and conduction band in semiconductors and insulators.
Answer:

Question 3.
Classify the following substances into ionic solids and molecular solids.
Answer:

Ionic Solid	Molecular Solid
NaCl, Zinc Sulphide	Ice, Solid NH3

Question 4.
What are isotonic solutions? Give one example.
Answer:
Isotonic solutions are solutions with the same osmotic pressure.
Blood plasma and 0.9% saline solution.

Question 5.
Write any two methods for preventing corrosion of metallic objects.
Answer:
Painting, galvanising, and applying grease.

Question 6.
The rate expression for a reaction is
Rate = k[A]^1/2 [B]^3/2
Calculate
(i) Overall order of reaction. (1)
(ii) Unit of rate constant. (1)
Answer:
(i) Overall order = \(\frac{1}{2}+\frac{3}{2}=\frac{4}{2}\) = 2
(ii) Unit of rate constant for nth order = \(\mathrm{mol}^{1-\mathrm{n}} l^{n-1} \mathrm{~s}^{-1}\)
For second order = \(\mathrm{mol}^{-1} l^1 \mathrm{~s}^{-1}\)

Question 7.
Write any two characteristics of Chemisorption.
Answer:
Chemisorption – Due to chemical bonds, irreversible, specific.

Question 8.
How will you prepare XeF₆? Give its structure.
Answer:

Question 9.
What are interhalogen compounds? Write any one of its uses.
Answer:
Inter halogen compounds are compounds formed by two different halogen atoms.
eg. IF₃, BrF₅, CIF₃, etc.
Uses:

• Used for uranium enrichment
• Are very useful chlorinating agents
• Used as non-aqueous solvents (any one)

Question 10.
Identify the products A and B in the following reaction:

Answer:

Question 11.
Which among CH₃COOH and is more acidic? Give reason.
Answer:
is more acidic due to the presence of an electron withdrawing Cl-group.
-I affect increases acidity.

Questions from 12-29 carry 3 scores each. (18 × 3 = 54)

Question 12.
‘Partial pressure of the gas in vapour phase is proportional to the mole fraction of the gas in solution.’
(i) Name the law stated above. (1)
(ii) Write any two applications of the law. (2)
Answer:
(i) Henry’s law
(ii) Applications of Henry’s law:

• When a soda bottle opens, a fizz sound occurs.
• Scuba divers use a little He dissolved in an oxygen cylinder.

Question 13.
(i) What are ideal solutions? (1)
(ii) A mixture of chloroform and acetone is a non-ideal solution. Identify the type of deviation shown by this mixture and give a reason for it. (2)
Answer:
(i) Ideal solutions – Obey Raoults Law
\(P_A=P^0 A \cdot x_n\)
or
ΔV_mix = 0
or
ΔH_mix = 0
(ii) Negative deviation: Due to the decrease in vapour pressure by the formation of H-bond between acetone and chloroform.

Question 14.
What are primary cells? Write an example for a primary cell and specify its anode and cathode.
Answer:
Primary cell – Can not be recharged or reused.
eg. dry cell, anode – Zn rod, cathode – graphite rod (carbon).

Question 15.
Represent the cell in which the following reaction takes place:

Answer:

Question 16.
Write the expression for the integrated rate equation of a first order reaction and derive the equation for its half-life.
Answer:

Question 17.
(i) What is meant by coagulation of sol? (1)
(ii) Write any two methods used for the coagulation of lyophilic Sols. (2)
Answer:
(i) Accumulation of colloidal particles is called coagulation of the sol.
(ii) By adding an electrolyte of oppositely charged colloidal particles.

Question 18.
(i) Which among the following pres can be concentrated by magnetic separation method? (1)
(A) Bauxite
(B) Haematite
(C) Zinc blende
(D) Calamine
(ii) Explain the hydraulic washing method for the concentration of ore. (2)
Answer:
(i) Haematite
(ii) Crushed ore is washed with running water, i.e., taken in a tank and water is poured. The gauge particles are washed away and heavier metals are left behind.

Question 19.
(i) What are the purposes of adding Na₃AlF₆ to purified alumina in the metallurgy of aluminium? (2)
(ii) Write any two uses of aluminium. (1)
Answer:
(i) To reduce the melting point of Alumina.
(ii) To make utensils, lab reagents.

Question 20.
(i) Explain Mond process for refining nickel. (2)
(ii) Which among the following can be refined by distillation? (1)
(A) Mercury
(B) Copper
(C) Silicon
(D) Zirconium
Answer:
(i)

M is treated with carbon monoxide and nickel tetra carbonyl is formed. It is again strongly heated to get decomposed.
(ii) Mercury

Question 21.
What is meant by lanthanoid contraction? Give its consequences.
Answer:
The steady decrease in atomic and ionic size of atoms from Lanthanum to Lutetium with increase in atomic number is known as Lanthanoid contraction.
Eg. Zr and Hf are similar
Consequences:

• Second and third transition series elements are similar and very difficult to separate.
• The basic strength of the hydroxides decreases from La(OH)₃ to Lu(OH)₃.

Question 22.
(i) Why are the transaction and their compounds used as catalysts? (2)
(ii) Which is the transition metal compound used as catalyst in the contact process? (1)
Answer:
(i) Due to its variable oxidation state and vacant d orbitals.
(ii) V₂O₅

Question 23.
(i) Name the type of structural isomerism exhibited by the following pair. (1)
[CO(NH₃)₅(SO₄)] Br and [Co(NH₃)₅Br] SO₄
(ii) Draw the Geometrical isomers of [Pt(NH₃)₂Cl₂]. (2)
Answer:
(i) Ionisation isomerism
(ii) Geometical isomers of [Pt(NH₃)₂Cl₂] are:

Question 24.
(i) Write the formulae for the following co-ordination compounds: (2)
(A) Tetraamminediaquacobalt (III) chloride
(B) Potassiumtetracyanidonickelate(II)
(ii) Which among the above is a homoleptic complex? (1)
Answer:
(i) A – [Co(H₂O)₂(NH₃)₄]Cl₃
B – K₂[Ni(CN)₄]
(ii) Potassiumtetracyanidonickelate (II) or K₂[Ni(CN)₄] is homoleptic since it contains only one type of ligand.

Question 25.
(i) Describe the preparation of ethanol from molasses. (2)
(ii) What is meant by denaturation of alcohol? (1)
Answer:

(ii) Ethanol is made unfit to drink by adding a little amount of methanol or pyridine to it. This is known as denaturation of alcohol.

Question 26.
(i) Alcohols have higher boiling points in comparison to hydrocarbons of comparable molar mass. Give reason. (1)
(ii) Arrange the following compounds in the increasing order of their boiling points: (2)
Propanol, Ethanol, Butan-1-ol, Butan-2-ol
Answer:
(i) Due to the presence of hydrogen bond.
(ii) Ethanol < propanol < butan 2-ol < butan 1-ol

Question 27.
(i) Name the type of linkage between the two monosaccharide units through oxygen atom in a disaccharide. (1)
(ii) Write two differences between DNA and RNA. (2)
Answer:
(i) Glycosidic linkage
(ii)

DNA	RNA
1. Deoxyribonucleic acid	1. Ribonucleic acid
2. The nitrogen bases present are (ATCG) Adenine, Thymine, Cytosine, Guanine	2. The nitrogen bases Present are (AUCG) Adenine, Uracil, Cytosine, Guanine

Question 28.
(i) Write the monomers used for getting the following polymers.
(A) Nylon-6
(B) Polystyrene
(ii) Which among the following is a condensation polymer? (1)
(A) Polyethylene
(B) Buna-S
(C) Nylon-6,6
(D) Teflon
Answer:
(i) (A) Nylon-6 – Caprolactam
(B) Polystyrene – Styrene
(ii) Nylon 6, 6

Question 29.
Match the drugs in Column-I with their therapeutic action in Column II.

Column-I	Column-II
(i) Antacid	(A) Neurologically active drugs
(ii) Tranquilliser	(B) Antimicrobial drugs
(iii) Disinfectant	(C) Treatment for acidity

Answer:
(i) Antacid – Treatment for acidity
(ii) Tranquilizer – Neurologically active drug
(iii) Disinfectant – Antimicrobial drugs

Questions from 30-40 carry 4 scores each. (11 × 4 = 44)

Question 30.
Explain the following:
(i) Crystal lattice
(ii) Void
(iii) Frenkel defect
(iv) F-centres
Answer:
(i) Crystal lattice: Three dimensional representation of particles of a crystal.
(ii) Void: The interstitial space in the crystal lattice.
(iii) Due to the absence of a cation from its lattice and is seen in the void. No change in density.
(iv) F centre – Electron trapped anion vacancy.

Question 31.
Solids can be divided into five types based on their response to the magnetic field. Describe any four magnetic properties.
Answer:
1. Ferromagnetic substances: ↑ ↑ ↑ ↑ ↑
Magnetic moments are in the same direction.
eg: Fe, Ni
2. Antiferromagnetic substances: ↑↓ ↑↓ ↑↓
Magnetic moments are in equal and opposite directions.
eg: MnO, NiO, Fe₂O₃
3. Ferrimagnetic substances: ↑↑↑ ↓↓ ↑↓
Magnetic moments are unequal and opposite in direction.
eg: Fe₃O₄, ZnFe₂O₄, MgFe₂O₄
4. Paramagnetic substances are attracted to a magnetic field and are shown by compounds or atoms with an unpaired electron.
eg. O₂, Cu²⁺.

Question 32.
(i) What are colligative properties? (1)
(ii) Name any two colligative properties? (1)
(iii) Calculate the osmotic pressure exerted by a solution prepared by dissolving 1.0 g of a polymer of molar mass 18500 g mol^-1 in 450 mL of water at 37°C (R = 0.821 L atm k^-1 mol^-1) (2)
Answer:
(i) Colligative properties are those properties which depend only on the number of particles.
(ii) (1) Relative lowering of vapour pressure
(2) Depression in freezing point
(3) Elevation in boiling point
(4) Osmotic pressure

Question 33.
(i) State Kohlrausch law of independent migration of ions. (2)
(ii) \(\Lambda_{\mathrm{m}}^0\) for NaCl, HCl, CH₃COONa are 126.4, 425.9 and 91.0 S cm² mol^-1 respectively. Calculate \(\Lambda_{\mathrm{m}}^0\) for CH₃COOH. (2)
Answer:
Kohlrausch Law
(i) The law states that the limiting molar conductivity of an electrolyte is the sum of the limiting molar ionic conductivities of the cations and anions of the electrolyte present in the solution.
\(\lambda_{\mathrm{m}}^0 \mathrm{NaCl}=\lambda_{\mathrm{Na}^{+}}^0+\lambda_{\mathrm{cl}}^0\)
(ii) \(\lambda_{\mathrm{m}}^0 \mathrm{CH}_3 \mathrm{COOH}=\lambda_{\mathrm{m}}^0 \mathrm{CH}_3 \mathrm{COONa}+\lambda_{\mathrm{m}}^0 \mathrm{HCl}-\lambda_{\mathrm{m}}^0 \mathrm{NaCl}\)
= 91 + 425.9 – 126.4
= 390.5 S cm² mol^-1

Question 34.
Consider the following equation:
K = \(A e^{(-E a / R r)}\)
(i) What does the term ‘A’ represent? (1)
(ii) The rate of a chemical reaction doubles when temperature is increased from 300K to 310K. Calculate the activation energy. (3)
Answer:
(i) A – Arhenius factor

Question 35.
Explain the following:
(i) Lyophilic colloid
(ii) Peptization
(iii) Tyndall effect
(iv) Electrophoresis
Answer:
(i) Lyophillic Colloid: Dispersed phase with very high affinity for dispersion medium.
(ii) Peptization: Conversion of a precipitate to colloid.
(iii) Tyndal effect: Scattering of light by colloidal particles.
(iv) Electrophoresis: Movement of colloidal particles under electric field.

Question 36.
(i) Explain the Ostwald’s process for the preparation of nitric acid. (3)
(ii) Write any two uses of nitric acid. (1)
Answer:
(i) 1. Catalytic oxidation of NH3 to form NO in the presence of platinum.

2. NO is converted to NO₂
2NO + O₂ → 2NO₂
3. NO₂ is treated with water to form HNO₃
NO₂ + H₂O → HNO₃
(ii) (a) Lab reagent
(b) Used for making fertilizers

Question 37.
(i) What are the products obtained when 2-Bromopentane is treated with alcoholic KOH? (2)
(ii) Identify the major product obtained in the above reaction. (1)
(iii) Name the rule that decides the formation of the major product. (1)
Answer:

(ii) Major product is Pent-2-ene / CH₃CH₂CH=CHCH₃
(iii) Saytzef Rule/Zaitsev Rule

Question 38.
Describe the following:
(i) HVZ reaction. (2)
(ii) Cannizaro reaction (2)
Answer:
(i) HVZ reaction: Carboxylic acid with α-hydrogen when treated with chlorine or bromine in the presence of red phosphorous gives α-halo carboxylic acids.

(ii) Cannizaro reaction: Aldehydes or ketones without α-hydrogen undergo oxidation and reduction in presence of conc. alkali to form acid salt and alcohol.

Question 39.
(i) Which among the following reduces Fehling reagent? (1)
(A) Propanone
(B) Benzophenone
(C) Ethanal
(D) Butanone
(ii) Name the class of organic compound obtained when aldehydes undergo reaction with the following reagents: (3)
(A) HCN
(B) Alcohol
(C) Hydroxylamine
Answer:
(i) (C) Ethanal (Aldehydes only gives Fehling’s test)
(ii) (A) Cyanohydrins
(B) Hemiacetal Acetal
(C) Oxime

Question 40.
(i) Which among the following is a primary amine? (1)
(A) (CH₃)₂CHNH₂
(B) C₆H₅NHCH₃
(C) (CH₃)₃N
(D) (CH₃)₂NH
(ii) Explain the reaction of Hinsberg reagent with primary, secondary and tertiary amines.
Answer:
(i) (CH₃)₂ CH NH₂
(ii) Hinsberg reagent- C₆H₅SO₂Cl (Benzene Sulphonyl Chloride)
1° amine + Hinsberg reagent → a precipitate soluble in alkali
2° amine + Hinsberg reagent → a precipitate insoluble in alkali
3° amine + Hinsberg reagent → no reaction

Reviewing Kerala Syllabus Plus Two Computer Science Previous Year Question Papers and Answers Pdf March 2020 helps in understanding answer patterns.

Kerala Plus Two Computer Science Previous Year Question Paper March 2020

Time: 2 Hours
Total Score: 60 Marks

Answer any 5 questions from 1 to 6. Each carries 1 Score. (5 × 1 = 5)

Question 1.
In inheritance the existing Class is called ____________
Answer:
Base / Parent class

Question 2.
The ____________operator is used to allocate memory location during run time (execution).
Answer:
new

Question 3.
Write an empty tag used in HTML.
Answer:
<br> or <hr> or <img>

Question 4.
Which attribute of <input> tag is used to make different kinds of controls like Text box, Radio button, Submit button etc.?
Answer:
type

Question 5.
The IP address of a Webserver connected to a do-main name is stored in ____________ .
Answer:
A record

Question 6.
Expand. ICT.
Answer:
Information and Communication Technology

Answer any 9 questions from 7 to 18. Each carries 2 Score. (9 × 2 = 18)

Question 7.
What is a pointer variable in C++? Write the syntax or example to declare a pointer variable.
Answer:
Pointer is a special variable which points to memory location of some other variable.
data_type *variable_name;
int *ptr;

Question 8.
Write any two differences in static and dynamic memory allocation.
Answer:
Refer Chapter 2. 3 Mark Qn.9.

Question 9.
Write any two advantages of using object oriented programming language. (OOP)
Answer:
Advantages of using OOP are
a) OOP allows modularity(divide the large programs into smaller ones)
b) It is good for defining abstract data types.
c) It allows data abstraction. That is it hides or protects data.
d) It allows code reusability
e) Real life entities can be easily created
f) It supports to create new data types.

Question 10.
Write the algorithm to add an item in to a queue which is not empty?
Answer:
If(REAR < N)then
REAR=REAR+1;
Q[REAR]=ITEM;
Else
Print “Over Flow”;

Question 11.
Briefly explain about Webserver.
Answer:
A computer with high storage capacity, high speed and processing capabilities is called a web server.
It is connected to the internet 24 × 7.

Question 12.
Write JavaScript statements to create a number and string variables.
Answer:
var n,str;
n=12;
str=”Plus Two”;

Question 13.
Breifly explain about any two built-in functions available in JavaScript.
Answer:
BUILT IN FUNCTIONS (methods)

1. alert() : This is used to display a message (dialogue box) on the screen.
   eg: alert(“Welcome to JS”);
2. isNaN(): To check whether the given value is a number or not. It returns a Boolean value. If the value is not a numberfNaNl then this function returns a true value otherwise it returns a false value.

Question 14.
List any four advantages of DBMS.
Answer:
Advantages of DBMS

1. Data Redundancy – It means duplication of data. DBMS eliminates redundancy. DBMS does not store more than one copy of the same data.
2. Inconsistency can be avoided – If redundancy odcurs there is a chance to inconsistency. If redundancy is removed then inconsistency cannot occur.
3. Data can be shared – The data stored in the database can be shared by the users or programs.
4. Standards can be enforced – The.data in the database follows some standards. Eg : a field ‘Name’ should have 40 characters long. Some standards are ANSI, ISO, etc.

Question 15.
Distinguish between the terms degree and cardinality used in RDBMS.
Answer:
Degree(to be remembered CD) – Number of Columns in a relation is called Degree.
Cardinality(to be remembered RC) – Number of rows in a relation is called Cardinality.

Question 16.
Differentiate echo and print used inPHP.
Answer:
The difference between echo and print

echo	print
take more than one parameter	only one parameter
Does not return any value	Returns TRUE or 1 on successful print and FALSE otherwise
Faster	slower

Question 17.
Write short note about any two applications of computational intelligence.
Answer:
Application of Computational Intelligence
A) Biometrics : Biometrics refers to the unique characteristics of a human being to recognize an individual such as finger prints, face recognition, iris, retina etc. Biometrics are used to record attendance Eg. In banks employee login is restricted by using finger print reader.

B) Robotics : It is a branch of scientific study associated with the design, manufacturing and control the movements of the robots. Roboticss are used in all the areas. Some of them are discussed below.

Question 18.
Name the types of interactions in e-Government
Answer:
Types of interactions in e-Governance e-Governance facilitates interaction between different stakeholders in governance
Government to Government(G2G)
Government to Citizens(G2C)
Government to Business(G2B)
Government to Employees(G2E)

Answer any 9 questions from 19 to 30. Each carries 3 Score. (9 × 3 = 27)

Question 19.
Describe about any three e-Learning tools.
Answer:
A) e Learning tools
a) Electronic books reader(e Books) With the help of a tablet or portable computer or any other device we can read digital files by using a s/w is called electronic books reader.

b) e text
The electronic format of textual data is called e-Text.

c) Online chat
Real time exchange of text or audio or video messages between two or more person over the Internet.

d) e Content
The data or information such as text, audio, video, presentations, images, animations etc, are stored in electronic format.

e) Educational TV channels
TV channels dedicated only for the e-Learning purpose : Eg. VICTERS (Virtual Class room Technology on Edusat for Rural Schools OR Versatile ICT Enabled Resources for Students)

B) Advantages of E Learning :

• It can offer variety courses to large number of students from distant location.
• It saves journey time and money, instructor fees, etc.
• People can enjoy e Learning with lower cost
• It enables people to do courses conducted by national or Inter national institutions.

C) Challenges to e Learning

• Face to face contact between student and teachers is not possible
• Proper interaction is limited lack of infrastructure facilities
• Its implementation requires computer and high speed Internet
• Pupil may not get proper motivation
• It does not provide a real lab facility

Question 20.
What is cloud computing? Write any two service? offered by cloud.
Answer:
It is an emerging computing technology. Here with the use of Internet and central remote servers to maintain data and applications. Example for this is Email service, Office Software(word processor, spread sheets, presentations, data base etc), graphic software etc. The information is placed in a central remote server just like clouds in the sky hence the name cloud computing.

Cloud service models (3 major services)

1. 1. Software as a Service(SaaS)
2. Platform as a Service(PaaS)
3. Infrastructure as a Service (laaS)

Question 21.
Differentiate indexed and associated arrays in PHP.
Answer:
Arrays in PHP
In PHP array is a collection of key and value pairs. Unlike C++, in PHP we can use either non negative integers or strings as keys.
Different types of arrays in PHP

• Indexed arrays
• Associate arrays
• Multi dimensional arrays.

Indexed arrays-: The elements in an array can be distinguished as first or second or third etc. by the indices and the index of the first element is zero. In PHP the function array() is used to create an array. Syntax: $array_name=array(value1 ,value2, ……………….);

Question 22.
Write short not about numeric and string data types of SQL.
Answer:
Data Types

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.
3. Dec or Decimal – It is used to store numbers with decimal point. It is declared as Dec (size, scale). We can store a total of size number of digits.
4. Int or Integer – It is used to store numbers without decimal point. It is declared as int. It has no argument. Eg: age int.
5. Smallint – Used to store small integers.
6. Date – It is used to store date. The format is yyyy- mm-dd. Eg: ‘1977-05-28’.
7. Time – It is used to store time. The format is Numeric data types are int(integer), dec(decimal), small int.
   String data types are char and varchar.

Question 23.
What are the different control structures used in JavaScript? Explain any one with an example.
Answer:
CONTROL STRUCTURES IN JavaScript
In general the execution of the program is sequential, we can change the normal execution by using the control structures.
1) Simple if

Syntax:
ifftest expression)
{
statements;
}

First the test expression is evaluated, if it is true, then the statement block will be executed other wise not.

* if-else
Syntax:
if(test expression)
{
statement block1;
}
else
{
statement block2;
}

First the test expression is evaluated, if it is true then the statement block 1 will be executed otherwise statement block2 will be evaluated.

Question 24.
Consider the following relations:
Arts relation:

Adm no.	Name	Batch
3001	Mpnju	A1
3009	Cristy	C1
4010	Fazil	B1
3090	Arun	K2

Sports relation:

Adm no.	Name	Batch
4015	Arjun	B1
4010	Fazil	B1
3005	Fathima	C2

Find the result of following relational algebra operation.
a) Arts ∩ Sports
b) Arts ∪ Sports
c) Sports – Arts
Answer:
a)

Adm No.	Name	Batch
4010	Fazil	B1

b)

Adm No.	Name	Batch
3001	Manju	A1
3009	Cristy	C1
4010	Fazil	B1
3090	Arun	K2
4015	Arjun	B1
3005	Fathima	C2

c)

Adm No.	Name	Batch
4015	Arjun	B1
3005	Fathima	C2

Question 25.
Explain about various types of web hosting.
Answer:
Types of web hosting
Various types of web hosting services are available. We can choose the yveb hosting services according : to our needs depends upon the storage space needed for hosting, the number of visitors expected to visit, etc.

1. Shared Hosting
2. Dedicated Hosting
3. Virtual Private Server (VPS)

Question 26.
Write HTML code to create a web page which in-cludes, the following table.

Answer:

<html>
<head>
<title>table</title>
</head>
<body>
<table border=”1''>
<tr align=”c6nter”>
<th colspan=”3">No. of Student</th>
</tr>
<tr align=”center”>
<th rowspan=”2">Boys</th>
<td> XI</td>
<td> 140</td>
</tr>
<tr align=”center”>
<td> XII</td>
<td> 60</td>
</tr>
<tr align=”center”>
<th rowspan=”2">Girls</th>
<td> XI</td>
<td> 75</td>
</tr>
<tr align=”center”>
<td>XII</td>
<td> 125</td>
</tr>
</table>
</body>
</html>

Question 27.
Differentiate static and dynamic web pages.
Answer:

Static web pages	Dynamic web pages
Content and layout is fixed	Content and layout is changed frequently
Never use database	Data base is used
Run by browser	It runs on the server and result get back to the c|ient(browser)
Easy to develop	Not at all easy

Question 28.
Explain about the operations performed on stack data structure.
Answer:
Operations on stack
a) Push operation: It is the process of inserting (adding) a new data item into the stack. If the stack is full and we try to add a new item into the stack makes the stack over flow.

b) Pop operation: It is the process of deleting (removing) a data item from the stack. If the stack is empty and we try to delete an item from the stack makes the stack underflow.

Question 29.
What is polymorphism? Write short notes about the types of polymorphism?
Answer:
Polymorphism, is the ability for a message or data to be processed in more than one form. This is achieved by function overloading, operator overloading and dynamic binding.
There are two types of polymorphism

a) Compile time(early binding / static)
polymorphism: It is the ability of the compiler’ to relate or bind a function call with the function definition during compilation time itself.
Examples are Function overloading and operator overloading

Function overloading : Functions with same name and different signatures(the jiumber of parameters or data types are different).

Operator overloading -: It gives new meaning to an existing C++operator.
Eg: we know that + is used to add two numbers, Operator overloading assigns + to a new job such as it concatenates two strings into one string.

b) Run time (late binding/dynamic) poly morphism: It is the ability of the compiler to relate or bind a function call with the function definition during run time, it uses the concept of pointers and inheritance.

Question 30.
Define structure. Write any two differences between structure and array.
Answer:
Structure is a group Of different types of logically related data referenced a single name.

Structures	Array
1. It is a user defined data type	1. Predefined data type
2. It is a collection of different types of logically related data under one name.	2. Collection of data elements of same data type having a common name
3. Elements referenced using dot operator (.)	3. Elements references using its subscripts (position value)
4. When an element of a structure becomes another structure nested structure and complex structures are formed	4. When an element’of another becomes another array, multidimensional arrays are formed.
5. Structures contains array as its elements	5. Array of structure can be formed

Answer any 2 questions from 31 to 33. Each carries 5 Score. (2 × 5 = 10)

Question 31.
a) The ____________ tag identifies the document as an HTML document.
b) Breifly explain about any two attributes of <BODY> tag.
c) Write the use of any four tags given below.
<B>, <U>, <SUB>, <PRE>, <IMG>, <BR>,
Answer:
a) <HTML>

b) We can use the attributes of <Body>tag
1) Bgcolor-specifies background color for the docu¬ment Body
Eg. <BODY BGCOLOR= “RED”>
2) Background – Sets the image as background for the document body
Eg. <BODY BACKGROUND= “C:/page1 ,jpg”>

c) a)<B> To make the content Bold.
b) <U> To underline the content.
c) <SUB> create a subscript.
d) <PRE> It is used to display the content as we entered in the text editor.
e) <IMG> Used to insert an image.
f) <BR> Break a line.

Question 32.
a) What are the different kinds of lists available in HTML? Briefly explain about the tags used for each kind.
b) Differentiate the following HTML code fragment:
<A Href = “http ://www.dbsc kerala.gov.in”>Higher secondary</A>
<A Href = Mailto : “scertkerala.gov.in”> SCERT </A>
c) Write any one attribute of <FRAMESET> tag.
Answer:
a) 3 types of Lists in HTML.
1) Unordered List (<UL>) – Items are displayed with square, circle or disc in front.

2) Ordered List (<OL>) – Items are displayed with the following type values.
Type = 1 for 1, 2, 3, …………….
Type = i for i, ii, iii, …………….
Type = I for I, II, III, ………….
Type = a for a, b, c, …………….
Type = A for A, B, C, ……………

3) Definition List (<DL>) – It is formed by definitions.

• <LI> – it is used to specify List items.
• <DT> – It is used to specify Definition Term.
• <DD> – Used to specify the description
• <A> is used to provide hyperlinks. Two types of linking. Its attribute is HREF.

1) External link – Used to connect 2 different web pages.
2) Internal link – Used to connect different locations of same page.

b) First one used to link a website and other is used to link an e-mail

c) Attributes are cols, rows, border or bordercolor.

Question 33.
a) Briefly explain about any two column constraints used in SQL.
b) Describe about any two DML commands of SQL.
Answer:
a) a) NOT NULL: it specifies that a column can never have null values, i.e., not empty
b) UNIQUE: it ensures that no two rows have same value in the specified column.
c) 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.
d) DEFAULT: it sets a default value for a column when the user does not enter a value for that column.
e) Autojncrement: This constraint is used to perform autojncrement the values in a column. That is automatically generate se¬rial numbers. Only one autojncrement column per table is allowed.

b) DML commands

1. Select – Used to select rows from a table. The keyword From is used with this. Where clause is used to secify the conition.
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.