Kerala Syllabus Class 8 Basic Science Model Question Paper Set 1

To reduce exam fear, Class 8 Basic Science Question Paper Kerala Syllabus Set 1 provide good practice.

Kerala Syllabus 8th Standard Basic Science Model Question Paper Set 1

Time: 2 hour
Total Score: 60

Instructions:

1. The first 15 minutes is cool-off time. This time is meant for reading the questions and planning your auswers.
2. This question paper includes 10 questions in sections A, B and C
3. You need to answer only one of the options provided for each of the choice-based questions.

PHYSICS

Time: 40 minutes
Total Score: 20

Section – A

Select the correct answer for questions 1 to 2. Answer all questions. (1 score for each question) (2 × 1 = 2)

Question 1.
Find out the odd one from following units and write it down
a) m
b) g
c) kg
d) mg
Answer:
a) m

Question 2.
Statement 1: Connecting an object to earth with a conductor is called earthing.
Statement 2: Due to its size and conductivity, the Earth can only donate electrons.
Analyse these statements and find out the correct choice from the following
a) Both statements are correct
b) Only the second statement is correct
c) Only the first statement is correct
d) Both statements are incorrect
Answer:
c) Only the first statement is correct

Section- B

Answer questions 3 to 8 in more than one sentence. Questions 7 and 8 have choices. (2 score for each question) (6 × 2 = 12)

Question 3.
Observe the picture below. Both beakers contain the same volume of water.
a) Which beaker experiences maximum pressure at the bottom?
b) Justify your answer.

Answer:
a) Beaker A experience maximum pressure at the bottom.
b) The height of liquid column or depth is more in beaker A than beaker B. So more pressure is experienced at the bottom of beaker A.

Question 4.
a) Draw magnetic lines of force between the given poles of magnets.

b) Write any two peculiarities of magnetic lines of force.
Answer:
a)

b) i) Magnetic lines of force do not intersect one another.
ii) When like poles of two magnets Come close.tile magnetic held lines bend away from each other.

Question 5.
Observe the figure.
a) Identify the device.
b) When you touch the metallic sphere of this device with a charged object, what do you observe?
Answer:

Question 6.
Draw a ray diagram showing image formation when an object is placed in front of a convex mirror.

Question 7.
A. The paths of two cars are as shown below. Car A started from P and reached R through Q and car B started from P and reached R through S.

a) What is the total distance covered by the car A?
b) What is the total distance covered by car B
Answer:
a) Total distance covered by the car A
= 500 + 600 = 1100 m

b) Total distance covered by car B
= 400 + 600 = 1000 m

OR
Question 7.
B. A book on a table is in a state of rest.
a) Identify the reference body for the above statement?
b) Considering the Sun as reference body, the book is in a state of (motion/rest)
Answer:
a) Reference body: Table
b) With respect to Sun, the book is in a state of motion

Question 8.
A. The height of an obj ect kept 12 cm away from a concave mirror is 1 cm. Calculate the magnification if an image of height 2.5 cm is formed in front of the mirror.
Magnification m = \(\frac{h_i}{h_0}\) = \(\frac{-2.5 \mathrm{~cm}}{1 \mathrm{~cm}}\) = -2.5

OR
Question 8.
B. Observe the figure and calculate the magnification.

Answer:
h = 10 cm.
h₁ = 5 cm
Magnification m = \(\frac{h}{h_0}=\frac{-10}{5}\) = -2

Section- C

Questions 9 to 10 carry 3 score each Question 10 has a choice. (2 × 3 = 6)

Question 9.
Electromagnets are temporary magnets that can be artificially made. Suggest three methods to increase the strength of electromagnets.
Answer:
i) Increase the number of turns of the coil,
ii) Increase current
iii) Increase the thickness of the core

Question 10.
A. a) Name the device which is capable of storing electric charge.
b) Name the ability of a capacitor to store electric charge.
c) What is its unit?
Answer:
a) Capacitor
b) Capacitance
c) farad (F)

Question 10.
B. One method of eharging an object is charging by induction.
a) What do you mean by charging by induction?
b) Write down the inference and reason based on the picture given below.

Answer:
a) Charging by induction is the method of charging an object without direct physical contact of a charged object.

b) (i) Redistribution of charges takes place in the metal sphere
(ii) The electrons in the metal sphere are repelled away from the glass rod.

CHEMISTRY

Time: 40 minutes
Total Score: 20

Section – A

Answer all the questions from 1 to 2. 1 score each. (2 × 1 = 2)

Question 1.
Match the following.
Chemicals added Colour of Glass obtained

a) Cadmium sulphide	i) Blue
b) Gold chloride	ii) Green
c) Chromium oxide	iii) Ruby red
d) Cobalt oxide	iv) Yellow

The correct match is
A. a-iv, b-iii, c-ii, d-i
B. a-ii, b-i, c-iv, d-iii
C. a-ii, b-iv, c-i, d-iii
D. a-i, b-iii, c-iv, d-ii
Answer:
A. a-iv, b-iii, c-ii, d-i

Question 2.
Two statements are given below.
(i) Hydrochloric acid (HC1) is naturally produced in the stomach to aid the digestion of food.
(ii) Antacids like Milk of Magnesia (Mg(OH),) work by increasing the pH of the stomach contents. Choose the correct one from the options given below.
A – Both statements (i) and (ii) are incorrect.
B – Statement (ii) is correct. However, statement (i) is incorrect.
C – Statement (i) is correct. However, statement (ii) is incorrect.
D – Both the statements (i) and (ii) are correct.
Answer:
D – Both the statements (i) and (ii) are correct.

Section-B

Two questions from 3 to 8 have choices. Each question carries 2 scores. (6 × 2 = 12)

Question 3.
Plastics are used for the following purposes. Identify the type of plastics used for the following purposes
a) To make a handle for a pressure cooker.
b) Plastic carry bags.
Answer:
a) Thermosets
b) Thermoplastics

Question 4.
A. The arrangement showing the electrolysis of water is given below? Analyse the diagram and answer the following.

a) Identify the gases A & B
b) Name an instrument used for the electrolysis of water in a convenient manner.
Answer:
A) a) A-Oxygen
B – Hydrogen
b)Hoffiman water vokarneter

OR
B. Water is a precious gift of nature.
a) Why is water known as a universal solvent?
b) What is the reason for water to occur in the liquid state at room temperature, even though its constituent elements (hydrogen and oxygen) are gases?
Answer:
a) skater is known as the universal solvent bcciuse it can dissolve more substances than any other liquid.
b) The reason isa special kind of attractive force between water molecules.This attractive force helps keep water in liquid form at room temperature.

Question 5.
Quicklime is taken in a steel cup. A little water is added to it.
a) What is the substance formed when water is added to quicklime?
b) Why do people handling quicklime wear gloves?
Answer:
a) When water is added to quicklime (calcium oxide), slaked lime (calcium hydroxide) is formed.
b) The reaction of quicklime with water is highly exothermic. If quicklime comes into contact with moisture on the skin, it will react and release a lot of heat. This can cause severe bums to the skin.

Question 6.
a) Find the number of molecules and the total number of atoms in the following.
i) O₂
ii) 5F₂
Answer:
i) O₂
No. of molecules – 1
Total no. of atoms – 2

ii) 5F₂
No. of molecules – 5
Total no. of atoms – 10

b) It is said that oxygen is an element and carbon dioxide is a compound. Why?
Answer:
In an oxygen molecule, there are only the same type of atoms. In carbon dioxide, there is the combination of atoms of the elements oxygen and carbon in a fixed ratio.

Question 7.
Magnesium reacts with oxygen in the air to form magnesium oxide.
a) Write the chemical equation for this reaction.
b) What is the product of magnesium oxide dissolved in water?
Answer:
a) 2Mg + O₂ → 2MgO
b) Magnesium Hydroxide

Question 8.
A. Give reasons for the following:
a) The handles of electrical tools and cooking utensils are made of non-metals.
Answer:
Electric tools and cookware are made of metals. Metals are good conductors of electricity and heat. Therefore, their handles are made of non-metal materials such as wood, plastic, and rubber to ensure safe handling without injury.

b) Metals like sodium, potassium, etc., are stored in kerosene.
Answer:
Sodium and potassium are very reactive metals. They react rapidly with air and moisture and are destroyed. They are stored in kerosene to avoid contact with the environment.

OR
B.
a) What is an alloy?
b) What are the benefits of alloying metals?
Answer:
a) Metals are combined with other metals or non-metals to make alloys.
b) It is done to obtain materials with desirable properties and to resist corrosion. A very small amount of non-metals like carbon, phosphorus, etc., is also added to such alloys.

Section – C

One question from 9 to 10 has a choice. Each question carries 3 scores. (2 × 3 = 6)

Question 9.
Magnesium ribbon is burned in the air, resulting in a bright light and a white powder as a product. This powder is then mixed with water.
a) What is the white product obtained?
b) Identify the chemical nature (acidic or basic) of the solution formed when the white powder product is dissolved in water, and state the reason based on the litmus paper test.
c) Write the chemical equation for the reaction that occurs when the white powder product is mixed with water.
Answer:
a) Magnesium oxide (MgO).
b) Basic-Red litmus turns blue.
c) MgO + H₂O → Mg (OH)₂ (Magnesium hydroxide).

Question 10.
A. a) Name the type of glass used to make laboratory equipment and cookware?
b) Find out the major components present in this glass?
c) Name the components present in all types of glass?
Answer:
a) Borosilicate Glass

b) Silica. Boron oxide or Boron tnoxide, (Also small amounts of (Na₂O) and (Al₂O₃).

C) Silica.

OR
B. a) What is the natural source from which natural rubber is obtained?
b) Explain why synthetic rubbers are predominantly used in the manufacture of tyres?
C) Name the first synthetic fibres?
Answer:
a) Natural rubber is obtained from the latex collected from the rubber tree.
b) Synthetic rubber shows less wear and tear compared to natural rubber. That is why synthetic rubbers are used in the manufacture oftyres.
c) Nylon

BIOLOGY

Time: 40 minutes
Total Score: 20

Section – A

Choices are given for questions 7, 8,10. Answer questions 1 and 2. Each question carries 1 score. (2 × 1 = 2)

I. Choose the correct order of the events that take place in karyokinesis.
I. Chromatids separate and move towards the two poles of the cell as daughter chromosomes.
II. Chromosomes are arranged at the centre of the cell.
III. Condensation of chromatin network into chromosomes.
IV. Chromosomes change into chromatin networks, and two daughter nuclei are formed,
a) I-II-III-IV
b) III-II-I-IV
c) III-I-IV-II
d) II-IV-I-III
Answer:
b) III-II-I-IV

Question 2.
Mutualism is an interaction between two species in which.
a) Both are benefited
b) both are harmed
c) one is benefited, and the other is harmed
d) one is benefited, and the other is neither benefited nor harmed.
Answer:
a) Both are benefited

Section – B

Write answers to questions 3 to 8. Each question carries 2 score. (6 × 2 = 12)

Question 3.
Some characteristics of a Kingdom are given below. Eukaryotes. Primary Producers.
a) Which Kingdom is this?
b) What are the other characteristics of this Kingdom?
Answer:

Question 4.
Complete the illustration.

Answer:
a) All organisms are made up of one or more cells,
b) New cells originate from pre-existing cells.

Question 5.
List the statements given below.
(a) More organelles
(b) Organelles are not membrane-bound
(c) No membrane-bound nucleus
(d) There is a membrane-bound nucleus
Prokaryotic cell: (b) and (c),
Eukaryotic cell: (a) and (d).

Question 6.
Suppose the biotic components of an ecosystem consists of Tree, Rat, crow, grasshopper, paddy, Frogs, snakes, Rabbit, Eagle and Squirrel.
Construct a food chain consisting of 5 trophic levels of this ecosystem and name the producers and primary consumers.
Answer:
Paddy → Rat → Crow → Snake → Eagle
The Producers are trees, Paddy and Primary consumers are rats, grasshoppers, rabbits, and squirrels.

Question 7.
A. Observe the newspaper article and answer the questions below.
GM crops as hope for farmers…
Kochi- GM crops are reaching farmers to increase their income….
a) What are GM crops?
b) Write examples of GM crops?
Answer:
(a) GM crops are genetically modified crops. Genetic engineering allows for the incorporation of new traits into crops by altering their genetic structure.

(b) Examples of such crops include cotton, which is resistant to pests, soybeans, which are resistant to herbicides, and rice, which is rich in vitamin A.

OR
B. Select and write down the possibilities of overcoming space constraints from those given below.
Sack farming, smart farming, aquaponics, greenhouse, vetical farming, terrace farming, tissue culture, mulching
Answer:
Sack farming, aquaponics, vertical farming, and terrace farming.

Question 8.
A. Observe the figure and answer the questions

a) Identify the parts labelled as X and Y in the figure
b) Write the function of X
Answer:
(a) X-Prostate gland, Y – Testis.
(b) Produces a fluid that contains the substances needed for the nourishment and movement of the sperm.

OR
B. Imagine a scenario where a fertilised ovum (Zygote) attempts to develop into an Embryo, but the inner
lining of the uterus is suddenly unable to form the blood and mucus mentioned in menstruation.
a) Identify the biological event that must have occurred for the zygote to form.
b) Explain the necessary of the blood and tissues in the development of the zygote.
Answer:
(a) Fertilisation.
(b) The blood, tissues, and capillaries that make up the thickened endometrium are formed to nourish and support the newly formed embryo as it grows.

Section – C

Answer questions 9 and 10. Each question carries 3 score. (2 × 3 = 6)

Question 9.
Arrange the given facts based on biodiversity by giving suitable titles.
• Protects wildlife along with the protection of historical monuments, natural resources and geographical features of an area.
• Research centres with facilities to collect seeds and gametes to preserve them.
• Different varieties of animals are protected and housed separately, and necessary arrangements are made available for their reproduction.
• Includes extinct organisms.
• Areas protected with the participation of the public.
Answer:

• In-situ conservation
  1. Protects wildlife along with the protection of historical monuments, natural resources and geographical features of an area.
  2. Areas protected with the participation of the public.
• Ex-situ conservation
  1. Research centres with facilities to collect seeds and gametes to preserve them.
  2. Different varieties of animals are protected and housed separately, and necessary arrangements are made available for their reproduction.
  3. Includes extinct organisms.

Question 10.
A. Observe the picture and answer the questions below.

a) What does the picture indicate?
b) What are the parts indicated by A and B?
c) What are the characteristics of the part indicated by A?
Answer:
(a) Nucleus
(b) A- Chromatin reticulum, B – Nucleolus
(c) Function of chromatin reticulum: Chromatin network is the structure that appears like a network of threads within the nucleoplasm. During cell division, these chromatin networks condense into chromosomes.

OR
B. Stem cells have special importance in modem medicine.
a) What are stem cells?
b) What are the characteristics of stem cells?
Answer:
(a) Stem cells are specialised cells that can develop into various types of cells such as muscle cells, nerve cells, blood cells, etc.

(b) Stem cells have the ability to create new types of cells. Hence, they are referred to as the body’s master cells. Stem cells help to eliminate damaged cells, promote the growth of new cells and maintain healthy tissues. In modem medicine, stem cells hold significant importance.