Competency Based Questions Class 8 Science

COMPETENCY BASED QUESTIONS
CLASS- VIII
SUBJECT- SCIENCE

INDEX
S. N. CHAPTER PAGE No.

1 Crop Production and Management 1

2 Microorganisms: Friend and Foe 5

3 Synthetic Fibres and Plastics 9

4 Materials: Metals and Non-Metals 12

5 Coal and Petroleum 16

6 Combustion and Flame 20

7 Conservation of Plants and Animals 24

8 Cell- Structure and Functions 27

9 Reproduction in Animals 31

10 Reaching the Age of Adolescence 35

11 Force and Pressure 38

12 Friction 40

13 Sound 44

14 Chemical Effects of Electric Current 47

15 Some Natural Phenomena 50

16 Light 53

17 Stars and the Solar System 56

18 Pollution of Air and Water 59

Chapter1
Crop production and Management
1- Observe the graph and write the answer-

Why do cotton growing areas are restricted in a few states only? (Comment in the box)

2- Identify the given diagram and answer the given questions-

Type of
irrigation

Two 1.
advantages

2.

3- Kanhaiya a small farmer ploughing his field with the help of a shawl. A eight class
student told him about new inventions by which the time and labour of farming can
be reduced. Can you mention any three such inventions and their benefits?

Innovations Benefits

1. 1.

2. 1.

3. 1.

1

4- The cultivation of crops involves several activities undertaken by farmers over a
period of time. Arrange the following activities in the correct sequence.

Preparation
Storageof soil Preparation of soil

Irrigation Manure/ Fertilizer

Protection from weeds Harvesting

5- Some microorganisms play an important role in the decomposition of waste organic
material like vegetable peels, biological litter etc. This action is very useful for nature
as well as farmers. List any two advantages of this activity as directed in the given
table-

Advantage for nature

Advantage for farmers

6- Identify the following instruments used in agriculture and write their name and
advantages in the round circle –

7- Manure is a natural substance that can be added to the soil to increase its fertility. Fertilizer
is given to the soil to promote fertility and productivity.
a- Write one advantage of both.

Advantage of Manure
Advantage of fertilizer

2

b- Which should be promoted by us and why?

8- a- Weeds are also controlled by using certain chemicals, called weedicides. Which
one of the followings is a good example of weedicide-

2,4 D 2,4 E 2,4 T 2,4 G

b- The weedicides should be used –

Just before onset 2,4 T during the Can be used any
of fruits vegetative growth time

9- Identify the state by name of festivals of harvesting –

Festival State

Pongal

Baisakhi

Bihu

Nabanya

10- The following pots labelled as A, B, and C are germinated by using different
cultivation methods.

3

Pot A- manure is added
Pot B- Fertilizer is added
Pot C- Neither manure nor fertilizer is added
a- Which one shows the least growth and why?
b- We should use the product of which pot and why?
c- What will happen if we grow legume plants and enrich the soil with rhizobium
bacteria?
Answer a-

Answer b-

Answer c-

4

Chapter 2
Microorganisms-Friend or Foe

1- Identify the group with the help of the diagram given-

Bactria Algae Fungi Virus

2- A student in a village area observed a few green patches on the boundary
wall of his school. He asked him about the green patches to his teacher. His
teacher clarifies the doubt of that student. Now he is able to recognize the
group of organisms belonging to the green patches. In your view, green
patch is most likely to be- (colour the correct box with pencilcolorr)-

A type of Bacteria A type of Algae

A type of Virus A type of Fungus

3- Eating curd every day will help in reducing cholesterol levels, thus
lowering the risk of high blood pressure and hypertension. It helps in
keeping the level of cholesterol balanced and the heart healthy. Do you
know in making curd a microorganism plays the most significant role? If
yes, please identify –

5

Bacteria Bacteria Bacteria Bacterial
Salmonella Bacillus Vibrio Lactobacillus

4- We all kept food in the refrigerator to enhance its longevity. How does the
refrigerator achieve this- (arrange only the correct in proper sequence)

Lower temperature Increase temperature Lower Humidity

Decrease ripening
Decrease temperature Decrease respiration rate
rate

5- Observe the diagram and comment on the followings-
a- Process involved
b- Microorganisms involved
c- Reason for the process

6- Identify the disease/ diseases categorized as a communicable disease-

Flu Cancer Malaria

Gout Diabetes Chicken pox

6

7- Read the following statements –
a- Streptomycin, tetracycline and erythromycin are antibiotics as they kill the same
microorganism from which these are produced.
b- Antibiotics are also used in poultry farms.
c- Antibiotics are very effective against viral diseases like flu and cold.
Write the correct statements in the box.

8- Passive immunity is provided when a person is given antibodies directly to the patient.
A good example is a new-born baby who acquires passive immunity from its mother
through the placenta. When during sports/cycling we often get cut and the doctor
advised us for an injection. In your view, such injection can prevent us from -

Rabies Tetanus Polio Covid

9- Arrange the following boxes in the correct sequence to make complete nitrogen cycle-

10- Preservatives are used to protect our foodstuff for a longer time. Answer as per
questions asked in different boxes.
a- Identify the type of preservative used in our kitchen

b- Write the mechanism

c- Define the process

7

Pickle Preservative name

Jam and Jellies Preservative name

Milk Name of process Definition of process

Sugar How act as a preservative?

Chemical Example 1 Example 2
preservative

8

CHAPTER 3
SYNTHETIC FIBRES AND PLASTICS
1- Cellulose a plant polymer which consists of many glucose molecules. Starch is a stored food
component in many vegetables and grains. Classify the given diagram of starch as
polymer or monomer

Answer:

2- Draw a diagram to show the:
(a) linear arrangement of units in plastic.
(b) cross-linked arrangement of units in plastic.

linear arrangement of units in cross-linked arrangement
plastic.

3- Name the form of polyester which is replacing materials like glass and used for
making bottles and jars-

Option A Option B Option C Option D

PET PVC CFC 2,4 D

4- Fill in the blanks with the suitable answer-

Nylon is another ________ (natural/artificial) fibre. The raw materials used in this is
obtained from ___________(plant/animal). It was prepared from_______,

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_______and_______ Nylon fibre was _________ and light. It was __________ and
very easy to wash. It is widely used in making __________.

5- Synthetic fibres are strong, elastic, light, wrinkle-resistant, and easy to wash and dry.
Even with so many advantages, we do not wear clothes made of pure synthetic fibres,
but a mixture of synthetic and natural fibres. Why is this necessary?

Reasons:

1.

2.

6- Which was the first true synthetic fibre?

Option A Option B Option C Option D

Silk PVC Polyester Nylon

7- Mention True and False. In case of a false statement modify the correct statement-

Statement True / Correct statement
False

Synthetic fibres are heat stable.

Rayon is obtained from a natural
source, wood pulp

All plastics have the same type of
arrangement of units

plastic can easily mould i.e. can be
shaped in any form.

Plastics do not react with water and
air

10

8- Synthetic fibres or synthetic fibres are fibres made by humans through chemical
synthesis. Nylon, terylene, and rayon are different kinds of synthetic fibres.

i- Rayon resembles with silk, therefore also known as

ii- Four R principles are reduced, reuse, recycle and

iii- Nylon is called fully synthetic fibre because it is prepared from

Water and air.

iv- used as is widely used as a substitute for natural wool for

knitting sweaters, shawls, blankets etc.

9- Although refrigerator preserving is more straightforward than traditional canning, you
must store jams, chutneys, and relishes in nonreactive, airtight containers. The best
containers to use are glass canning jars, found in large supermarkets and some
hardware stores. Can we store jams and pickles in plastic containers? Give reason.

Reason:

10- i-Which material is used for coating non-stick kitchen wares-

a- Teflan b- Melamine

Which material is used in making electrical switches-

a- Melamine b- Bakelite

11

CHAPTER – 5
MATERIALS: METALS AND NON-METALS

1- The boiling point is the temperature at which a liquid boil at. The boiling point of
water is 100 o C . Mark tick boxes having correct statements-

The boiling point is different at different At high altitudes, the boiling point is
pressure. different from the sea level.

The pressure cooker is based on the
principle of increased temperature at
° C / ° F are used aa s unit of boiling
high pressure
point

2- A goldsmith has a piece of gold with 1 cm length, 1 cm width and 1 cm height. With
the help of that piece of gold, he makes the following item -

With what property he would have done it? Explain.

3- Observe the following diagram and make a list of any four items which can be used
in place of the iron nail-

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4- Pair the followings (Silver and Coal) with the correct answer-

Ductile
SILVER
Dull
Poor
conductor

COAL Malleable

Brittle

5- The given diagram is related to the chemical nature of solutions. A particular paper is
used to determine the nature of the solution as acidic, basic and neutral. Give answers
to the questions related to the diagram-

Statement Possible answers Correct
answer

In which colour such a- Red and green
papers are available in b- Blue and red
the lab? c- Red and orange
d- Yellow and blue
What is the correct a- pH value 7 represents neutral
statement about the pH b- pH value < 7 is acidic
scale? c- Ph value > 7 is basic
d- All are correct
The litmus paper is a- Lichen
obtained from- b- Algae
c- Rose
d- Turmeric

6- Fill in the boxes with correct answers-

a- Oxides of metals are in nature.

b- SO2 + H20 =

c- Na metal is stored in due to its vigorous nature.

d- Phosphorus is a and stored in

e- The colour of CuSO4 is and Cu is

13

7- Identify the correct chemical reaction from the given set –

Chemical reactions Correct option

a- Vaporization of water at high temperature

b- Rusting of the iron rod while exposed to air and moisture

c- A metal is drawn into wires and used in electric wire
formation

d- A electrical tester glow while touch in electric current
e-

8- Identify the correct statement about S , Fe , Atoms and Element –

i- Sulphur and Irons are examples of an element.
ii- The atom is the smallest unit of an element.
iii- The atom of an element remains unaffected by physical changes in the element.
iv- An atom of liquid sulphur would be exactly the same as the atom of solid or
vapour sulphur.
a- Only I and ii are correct
b- Only ii and iv are correct
c- Only I, ii and iii are correct
d- All are correct.

9- The amount of iron you need is: 8.7mg a day for men aged 19 and over. 14.8mg a
day for women aged 19 to 49. 100 grams of prunes contain 0.93 mg of iron while
raisins contain 2.6 mg of iron. To determine the level of Fe in our body which of the
following test is performed- (you can tick one/ more than one)

14

Liver function test Eosinophil test of Haemoglobin test of Kidney function
blood blood test

Iron helps in which of the following activities in our body- (you can tick one/ more than one)

Oxygen transport CO2 Transport Energy generation Reduces tiredness
and fatigue

10- Math the column with the correct pair-

Lustrous non-metal Soft enough to cut

Potassium and sodium Nonmetal in liquid state

Mercury Iodine

bromine Kept in water

phosphorus Metal in liquid state

15

Chapter 5
Coal and Petroleum
1- Year by year, global energy consumption is getting higher, therefore the use of fossil
fuels is getting higher too. The world does not have enough renewable energy to
supply industries’ and populations’ full demand.

i- In graph the demand of gas is highest? Can you explain?
ii- Can you suggest two methods to minimize the use of fossil fuels?

2- Observe the following data related to coal production and write answers-

i- Which country produces most of the coals?
ii- What would be the reason for the such high demand for coal?
iii- The use of coal in India is decreasing. (True / False)
iv- India uses more coal than the USA. (True / False)

16

3- Fill the box with the appropriate answer-

Used in For

Industries like BHEL
Coal
Rail engine

Thermal plants like NTPC

4- Coal is a sedimentary deposit composed predominantly of carbon that is readily

combustible. India is the second largest producer and consumer of coal after China.

The use of coal is not recommended as it produces a lot of air pollutants.

i- The main carbon component of coal is carbon. (true/false)

ii- Jharkhand has the most coal reserve in India. (true/false)

iii- Fill the given boxes with different products of coal –

COAL

5- The petroleum industry in India dates back to 1889 when the first oil deposits in the
country were discovered near the town of Digboi.
i- An organization established in India in 1978, under the aegis of the Ministry of
Petroleum and Natural Gas of the Government of India that is engaged in
promoting energy efficiency in various sectors of the economy-
a- CPRA
b- PCRA
c- RERA
d- KVIC
ii- Label the state in the map of India where first oil deposits were discovered.

17

6- In the given table fill the name of three states other than the state where digboi is
located. Also mention the two river basins where we get petroleum products.
State 1 State 2 State 3 Two river basins

7- On the basis of statements write the correct responses-

i- are the substances obtained from petroleum and

natural gas.

ii- Hydrogen gas obtained from natural gas, is used in the production of

iii- Is also known as black gold.

8- Marks the statements correct/incorrect-
i- Petroleum is also known as crude oil.
ii- It is a natural resource.
iii- It cannot mix in water as heavier than water.
iv- it is made up of a long chain of carbon and hydrogen.
v- Different forms of petroleum products are formed by simple diffusion
techniques.
9- Find out the characteristics of coke –

purest form of Non porous Used in metallurgy All are correct
carbon

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10- Air is an inexhaustible natural resource
a- Which of the following is an inexhaustible natural resource?

Option a Option b Option c Option d

Coal Mineral Sunlight Forest

b- Petroleum was formed from organisms

Option a Option b Option c Option d

living on the land living on the plants living in the sea living on the rocks

19

Chapter-6
COMBUSTION AND FLAME
1- Combustion is a chemical process in which a substance reacts rapidly with a specific
gas and gives off heat.
i- Among combustion and explosion which one is a slow combustion in
comparison to the other?
ii- Combustion is a physical process (True/ False)
iii- Which specific gas is required in combustion?
2- The energy released by the exothermic reactions increases the temperature. During
combustion, heat is produced.
i- Combustion is a (mark on the correct option)
a- Oxidation process ()
b- Reduction process ( )
ii- Oxygen is a neutral gas that supports the reduction process during combustion-
a- True
b- False
3- Identify the type of fuel from the given box and also write their names?

i- Liquid
ii- Solid
iii- Gas
4- I- Can you infer anything at all about the role played by air in the process of burning?
ii-Identify the name of the gas which is responsible for the following event/ events.

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5- Calorific value is the amount of heat energy released during the complete combustion
of a unit mass of fuel. It is expressed in kJ/kg. What conclusion you will draw from the
following data-

i- Which of the fuel will produce maximum energy?
ii- Coal has generally < 10% volatile matter and about 90 % fixed carbon). Compare
its calorific value with wood.
iii- From which sources we can get methane?
iv- Is the use of cow dung cake judicious?
6- Observe the diagram given under. The diagram depicts that a steady candle flame is
introduced on a clean slide. After some time we observe the black colour in a circular
manner on the slide.

i- What is represented by the black circular ring?
ii- What is the chemical nature of the component of black spot?
iii- Are you able to define unburnt carbon?
iv- Does candle may cause air pollution?

21

7- Global warming is the rise in the temperature of the atmosphere of the earth. This
results, among other things, in the melting of polar glaciers, which leads to a rise in
the sea level, causing floods in the coastal areas.
i- Increased concentration of which gas mainly causes global warming?
ii- What will happen if CO2 % becomes zero?
iii- What impacts you will observe on plants due to increased global warming?
iv- Suggest two ways to reduce the impact of global warming.
8- Match the columns-

Column A Column B Column C Column D

Oxides of Released from CNG
sulphur and unburnt coal
nitrogen

Cleaner fuel Acid rain May cause
serious
suffocation and
death

carbon Left negligible suffocating and
monoxide gas amount of corrosive gas
unburnt material

9- Which one the following caught fire easily and why?

Answer:

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10- Observe the diagram and answer-

i- Label the Hottest part

ii- Label the Least hot part

iii- Which zone represents complete combustion?

iv- Which type of reaction is shown by melting wax?

v- Burning of the candle is a chemical reaction. True/ False

vi- “B” is moderately hot. True/ False

23

CHAPTER – 7
CONSERVATION OF PLANTS AND ANIMALS
1- Now a days major threat to the wild animal is due to –

Afforestation Industrialization Global warming Deforestation

2- UNESCO suggested that Biosphere reserves are
'learning places for sustainable development'. Are
you able to locate the followings in the map of
India-

Satpura

Panchmarhi

Nilgiri

3- From 2002 to 2021, India lost 371kha of humid primary forest, making up 19% of its
total tree cover loss in the same time period. The total area of humid primary forest in
India decreased by 3.6% in this time period. Mention three major consequences of such
loss of primary forests-

1.

2.

3.

4- From 2001 to 2021, India lost 2.07Mha of tree cover, equivalent to a 5.3% decrease in
tree cover since 2000. From 2001 to 2021, India lost 34.8kha of tree cover from fires
and 2.03Mha from all other drivers of loss.
Write the consequences of desertification-

Desertification

24

5- a-Which of the following are involved to make a biodiversity community- (Mark at correct
pic)

b- The place where flora and fauna are conserved in the natural habitat is/are-
(i) Zoological garden (iii) Wildlife sanctuary
(ii) Botanical garden (iv) National Park
(a) i & ii (b) ii & iii (c) iii & iv (d) i & iv

6- Match the option a, b and c with the correct statement –
Statement 1- where animals are protected from any disturbance to them and their
habitat.
Statement 2- reserved for wildlife where they can freely use the habitats and natural
resources.
Statement 3- Large areas of protected land for the conservation of biodiversity and
traditional life of the tribals

Option ‘a’ Option ‘b’ Option ‘c’

National Park Biosphere Reserve Wildlife Sanctuary

7- Organize the followings into flora and fauna –
Tiger, Mango, Cat, Snake, Lizard, Guava, Banyan, Silver fern, Lichen

Flora

Fauna

8- a- Endemism is the state of a species being found in a single defined geographic
location, such as an island, state, nation, country or other defined zone. List any two
endemic species and exotic species in relation to our country.
b- Species is a group of populations that are unable to interbreed. (True/ False)
9- Satpura national park is famous for which of the following.

Elephant reserve Tiger reserve Rhino reserve Lion reserve

25

Satpura National Park is located in which state-

Madhya Pradesh Jharkhand Orissa Chhattisgarh

10- a- identify the box which is an integral part of a component of the ecosystem-

SUNLIGHT PLANT

BACTERIA SOIL

ANIMALS AIR

FUNGI ALL ARE COMPONENTS OF
ECOSYSTEM

b-List names of endangered animal species of India.

Answer:

26

Chapter- 8

CELL ELL — STRUCTURE AND FUNCTIONS

1- Hen egg contains egg albumin (protein). Other than this protein what is true about the
hen’s egg-
Statement True / False

It is a cell

It is a tissue

It has embryo

It has no fat

It divides to form chicken

The outer covering of the egg is calcium carbonate

2- Label the following as a unicellular / Multicellular

3- Observe the following diagram and answer the related questions-

27

a- It is an animal cell. True/ False
b- It is a plant cell as it has …………………….
c- The cell wall is a feature of both animal cells and plant cells. True/ False
d- Plant cell contains chloroplast. True/ False

4- Label the parts A to E and mention their functions-

Label Name Function

A

B

C

D

E

5- Identify the incorrect statement about cell membrane-

1. It encloses cytoplasm and nucleus
2. It is thicker than the plasma membrane
3. It allows the movement of substances
4. In a few cells it is surrounded by thicker walls

6- Classify the following terms into cells, tissues and organs
Ostrich egg, red blood cell, Neuron, human blood, Muscles of hand, kidney, liver

28

CELL

TISSUE

ORGAN

7- Gene is a unit of inheritance in living organisms. It controls the transfer of a hereditary
characteristic from parents to offspring. The children possess the genes of their parents
but they don’t look like them-
a- Genes play no role
b- The features of genes are never expressed by children
c- The different combinations of genes from parents results in different characteristics
d- All are incorrect
8- Select the correct option (s)-
i- The nucleus of plants and animals are similar
ii- The nucleus of plants, animals, and bacteria are similar
iii- The nucleus of bacteria is different from plant and animals
iv- Bacteria don’t have a nucleus.
a- Only i , ii and iii are correct
b- Only i and iii are correct
c- Only ii is correct
d- All are incorrect
9- Identify the prokaryotic and eukaryotic cells-

A B

C
D

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10- a- It is very known fact that many plants like Tradescantia are photoautotrophs. They are able
to perform photosynthesis and can make their food. Which cell organelle is helpful in this
process-

Nucleus Vacuole Plastid Cell wall

b- Which of the following is not observed in the nucleus of plant cell-

Chromosome Gene Chlorophyll Nucleoplasm

c- The following pairs are not correctly matched, arrange these is correct order-
Peudopodia ---------------Chloroplast

Primitive nucleus -------- Amoeba

Gene ………………………….. Cytoplasm

Gelly like ……………………. Chromosome

Answer:

30

CHAPTER- 9
REPRODUCTION IN ANIMALS
1- Identify correct statements about the zygote-

Formed by the fusion Develops into It is a product of All are
of sperm and egg offspring sexual reproduction correct

2- Which type of reproduction is exhibited by the following diagrams-

3- a- Roslin Institute in Edinburgh successfully cloned a sheep. The name given to that
sheep was-

Rosie Dolly Selvi Chelsa

b- The process by which sheep was produced is known as -

4- In asexual reproduction only single parents are involved. The offspring are similar as
their parent. Which statement/ statements is/ are correct/ incorrect about asexual
reproduction- (put correct/ incorrect marks)

Potato plants propagate through asexual reproduction

The progenies of asexual reproduction show more variation

The sexually reproducing organism have poorly developed
reproductive system

Zygote is product of asexual reproduction

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5- At a time male gametes are produced in an enormous amount in comparison to the
female gamete in human females. The number of eggs is limited in human females.
Mention the site of production of male and female gametes in the following format-

Gamete Name Site of production Number of
gametes

Male

Female

6- The given diagrams are of male and female reproductive systems-

a- Label the indicated parts.
b- What is the role of uterus?
7- Indicate whether the following statements are True (T) or False (F). also mention the
correct statement in the case of a false statement –

Statement T/ F Correct statement if given
statement is false

Oviparous animals give birth to young ones.

Sperm is a single cell.

Amoeba reproduces by budding.

Fertilisation is necessary even in asexual
reproduction.

Binary fission is a method of asexual
reproduction.

32

8- Amaoeba divides by method. The most common method

is . The given diagram represents the reproduction

steps of Amoeba. What is significance of step “c”.

9- Complete the crossword puzzle using the hints given below-
STRAIGHT-
a- Ovary releases
b- Sperms have
c- Another term for the fertilized egg.
d- Vivipary occur in _____________fertilization
DOWN-
a- Sperm is a type of ______________
b- Internal organization is shown by_____
c- Fertilisation outside the body_
d- Zygote develops into _________________

G E

I L

C

W H E

10- a- Label the given diagram-

33

b- Rearrange the events of the life cycle of silkworm and frog in correct sequence-

Larvae / Caterpillar Early Tadpole

Pupa Egg

Egg Adult

Late Tadpole

34

CHAPTER- 10
REACHING THE AGE OF ADOLESCENCE
1- Ranu is a brilliant student. He is admitted to class one at the age of 7 years. Now he is
studying in class 5. He looks different from other students. What do you think about
the statement-
i- He is in adolescence age.
ii- Adolescence age has some specific feature which is different from non-adolescent
age children.

Only i is correct Only ii is correct Both are incorrect Both are correct

2- In a class of 40 students 23 are girls and the remaining are boys. The class has an
average of 10- 11 years. Based on this statement find out the correct option from the
followings-

i- Adolescence begins around the age of 11

ii- In girls, adolescence may begin a year or two earlier than in
boys

a- Both statements are correct
b- Both statements are incorrect

3- Arrange the followings in the correct sequence-

Reproductive
maturity Adolescence

Puberty Infancy

35

4- Adolescence is a time for growth spurts and puberty changes. It is the period of
transition between childhood and adulthood. We can calculate the total height of a
adolescent by a simple formula- identify the correct formula-

Present height (cm) Present height (cm)

X 100 X 100

full height at this age full weight at this age

Full height (cm) Not possible

X 100

Present height at this age

5- Roohi is very curious to know the reason behind the similarity of a children with their
family members. Select the correct reason from the given options-

Cells

Eggs
The similarity of child with a family member is due to -
Sperms

Genes

6- The given diagram also determines the onset of puberty age.

A

36

Label the “A” and also mark the correct statement-
a- “A” is more developed in boys than girls. ()
b- It determines the louder and pitched voices in girls and boys respectively. ()
7- Form the given statements mark true/false

Statement True/ false

Testes start producing sperm at age of 21 years

In girls, egg formation starts after adolescence age

Beard in boys is a secondary sexual character

8- Write the name of the hormone and its functions-
Hormone Function

TESTES

OVARY

9- In a family there are two children. Identify their sex and also mention the parent
(father/mother) from whom they receive the chromosome-

Set of chromosomes Sex of children Father provides Mother provides

XX

XY

10- Mark the statement is true or false-

S.N. Statement True / False

1 Thyroxine is also secreted in frogs.

2 Growth hormone is secreted by the kidney

3 Insulin prevents the diabetes

4 Pancreas helps in digestion

5 Liver is the largest organ

6 Adrenal gland is located near to kidneys

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CHAPTER- 11
FORCE AND PRESSURE
1- a- A push or a pull on an object is called ………………………………… (force/ pressure)
b- Repulsion between similar poles ……………….. (push/pull)
c- the given diagram represents …………. (push/pull)

2- The strength of a force is usually expressed by its –

Attitude Aptitude Magnitude Substitute

3- The International System Of Units (SI) is the metric system that is used universally as a
standard for measurements. The SI unit of pressure is –

Watt Pascal KJ / kg Jule

4- Newton/ Metre2 is equal to –
Watt Pascal KJ / kg Jule

5- Pressure can be calculated by which formula-
Pressure = Force x Area Pressure =( force ) 2 / area

Pressure = force x (area) 2 All are incorrect

6- A force of 50 Newtan is applied on an area of 2 meters 2. Compute pressure being
applied to the area. Also, mention the unit of pressure.

Option a Option b Option c Option d

100 1250 200 All are incorrect

7- Among muscular force, gravitational force, magnetic force, electrostatic force,
frictional force, identify contact and noncontact force-

Contact force

Non-contact force

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8- Which statement is correct about force-

Statement Correct / Incorrect

may make an object move from rest.

l may change the speed of an object if it is moving

l may change the direction of motion of an object.

May bring about a change in the shape of an object.

9- It is easier to walk on sand if we have flat shoes rather than shoes with sharp edge heels. It is
because- (identify correct one)

Flat shoes have more area so will exert less pressure

Flat shoes have more area so will exert more pressure

10- Identify the type of force-

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CHAPTER – 12
FRICTION

1- What enables a ladder to lean against the wall?

2-
When a runner's foot comes in contact with the ground,
friction occurs between the two objects. The direction of the
arrow shows which types of resistance-

3- The different types of surfaces have different intensity of friction. The following table
shows two types of surfaces. Which on shows high friction-

4- Fluid friction is the force that opposes a motion that takes place within fluids or in
between fluids. The frictional force exerted by fluids is also called-

Option A Option B Option C Option D

Drag Pressure Force Friction

5- An average, tyre life ranges from between 3 -5 years, and between 30,000 to 60,000
miles. But we often see that wearing the tyres is more in rural areas than in urban
cities. Identify the main cause-
i- Urban areas have more smooth roads than villages
ii- Smooth roads have less friction effect
iii- Friction is the main cause of wearing of tyre
a- Only ii is correct
b- Only iii is correct
c- All are correct

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6- A pulley is a wheel with a groove along its edge, that holds a rope or cable. What is
the role of the pully –

Option A Option B Option C Option D

It changes the It reduces Decreases rate of All are correct
direction of force frictional force contact force

7- Air resistance is a special kind of frictional force that acts on objects as they travel
through air. Identify the situation where this frictional force is ABSENT, from the
ones given below.

Option A Option B Option C Option D

In all of
these

Bulb hanging from Cricketer hit the ball
the roof
Man with parachute

8- Different types of motion of the object gives rise to different types of friction.
Generally, there are 4 types of friction. They are static friction, sliding friction, rolling
friction, and fluid friction. Identify the type of friction-

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A knife is placed on
the top of a table
Skiing on the Swimming in river
mountain

A B C

9- Friction produces heat which damages the moving parts of a machine. Fluid friction
occurs between fluid layers that are moving relative to each other. How can fluid
friction be minimised?

Option A Option B Option C Option D

By adding By giving suitable By increasing All of these
lubricants in the shape force
water

10- A football player hit the ball several times in various ways and Sunil who is outside
the field observes the following things-

a- When kicked on the surface it lost its velocity after some time
b- When the ball is kicked in the air, it falls on the ground after some time.
c- Why do all the football balls have a similar shape

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(Which one of the following pairs are correct)

A, B, C Due to friction, due to gravity, to reduce friction

A, B, C Due to gravity, Due to friction, to reduce friction

A, B, C Due to friction, to reduce friction, Due to friction

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CHAPTER – 13
SOUND

1- How does it travel from one place to another-
Option A Option A Option A Option A

As atoms As waves As sensation As decibel

2- When air has been removed completely from a vessel, it is said that there is a
vacuum in the vessel.

What will be the quality of the alarm clock sound in the above experiment? Also
mention the reason for your answer.

Option A Option B Option C Option D

Very low Low Very loud No sound

Reason:

3- a-How many vocal cards are present in humans-
b- sound is produced by vibration in -
Option A Option B Option C Option D

No of vocal card 1 2 0 2 pair

Sound production Windpipe Trachea Tongue Vocal cord

4- observe the diagram given below and answer-

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a- Label 1,2,3 and 4
b- Mention the role of 4

5- To and fro or back and forth motion of an object is called-

Option A Option A Option A Option A

Vibration Frequency Hertz Linear Motion

6- Frequency is the number of occurrences of a
repeating event per unit of time. In the given
diagram identify the event in which frequency s
more than other. Also give the reason.

Answer:

7- Ramesh was enjoying the rainy season. Suddenly he is scared by a thunderbolt 4
seconds after he saw lightning in the east direction. Which formula we can use to find
out the distance of lightning from Ramesh?
Hint: (speed of sound= 300 m/ s)
a- Velocity = time/distance
b- Distance = velocity X time
c- Distance is cannot be calculated by the above data.
d- Distance will be infinite as lightning occurs in clouds

8- Decibel is a unit to measure the
level of noise. Passenger cars has
a decibel range of about 70 while
jet plane has 120 dB.
Increase in decibel leads to –

a- Noise Pollution
b- Air pollution
c- Radiation pollution
d- No pollution

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9- Match the column with correct pair-

Column A Column A

< 20 Hz Inaudible by human

20,000 vibrations per second Audible by human

19000 Hz Audible for dog

> 20,000 Hz Inaudible by human

10- A simple pendulum makes a few oscillations in a few seconds. How can you calculate
the time period and frequency of its oscillation?
i- Time period = time/ no of oscillation
ii- Time period= no of oscillation/time
iii- Frequency = no of oscillation/time
iv- Frequency = time/no of oscillation

A i and ii are correct

B i and iii are correct

C Ii and iii are correct

D Ii and iv are correct

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CHAPTER- 14
CHEMICAL EFFECTS OF ELECTRIC CURRENT

1- Distilled water cannot conduct electricity while tap water is a good conductor of
electricity. The reason is –

A Distilled water does not contain ions

B Tap water contains ions

C To conduct electricity ions are necessary

D Only a and c are correct

2- Fill the blank spaces with appropriate answers-
An electric bulb glows due to ________ (heating / physical) effect of current. The
object to be electroplated is taken as ____________ (anode/cathode) electrode.
Distilled water is ____ conductor of electricity while tap water is _____ conductor.
(good/ bad).

3- In the given diagram a circuit is used to test whether lemon juice is good or bad
conductor of electricity.

a- What will be your answer?

b- In place of lime juice what other solutions we can use? Give any two examples.

c- What will happen if lemon juice is replaced by sugarcane juice and distilled water?

Answer
a
Answer
b
Answer
c

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4- Fill in the blank with the correct options-

When the __________(liquid/ sold) between the _____(one/ two) ends of the tester
allows the _______(electric / metallic) current to pass, the circuit of the tester
becomes ________(complete/ incomplete) . The current __________(hault/ flows) in
the circuit and the bulb _______(remains same/ glows) .
5- Write the full form of the given diagram –

a Light emerging diode

b Light enhancing diode

c Light emitting diode

6- Chromium plating is done on car parts, bath taps, kitchen gas burners, bicycle
handlebars, wheel rims etc.
i- Name the process-

a- Electrocoating

b- Electroplating

c- Electronics

d- Electromagnetism

ii- What is the advantage of this process? Mention any two.

Answer:
1.
2.

7- Complete the following equation-
i- When an electric current is passed through the copper sulphate solution

CuSO4 _____ + ________
ii- Cu will deposit at the positive terminal. (True/ False)

8- In the following diagram label the A and B in both diagram

B

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a. a.

b. b.

9- In yesr 1800 a scientist had shown that if electrodes were immersed in water, current was
passed.
a- Name the scientist
b- He also observe bubbles. Write the name of gases who were observed as bubbles.
Anser
a.

b.

10- An electrolyte is a-

Option a Option b Option c Option d

Solids that conducts liquids that does not Solids that does not liquids that
electricity conduct electricity conducts electricity conduct
electricity

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CHAPTER- 15
SOME NATURAL PHENOMENA
1- Lightning is a visible electrical discharge from a cloud. What is your view about lightning and
the spark from your clothes?

Option a Option b

Both are different Both are same

2- When we rub against something, we
get charged. Transfer of charges
takes place which results in sparks. This is an example of-

Option a Option b

Static electricity Non-static electricity

3- We can create charge on rubbing the
balloon, refill, comb etc. based on your
observation complete the following sentences with right answer-
Hint: repel, attract

a- A charged balloon ___________a charged balloon.

b- A charged refill ______________a charged refill.

c- A charged balloon ____________a charged refill

4- Mention the reason of two different diagrams given below-

Balloons attracted Balloons repel

Reason: Reason:

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5- There are two types of charges positive; (+) and negative; (-) Which device is used to find
whether an object is carrying charge or not ?

Option a Option b Option c Option d

Periscope Electroscope Microscope Kaleidoscope

6- Lightning Conductor is a device used to protect buildings from the
effect of lightning. Some metal plates are provided in buildings to
protect us from electrical shocks due to electrical current leakage.
a- The process of transferring charge from a charged object to the
earth is called-

Option a Option b Option c Option d

Earthing Airthing Conducting Plating

b- In earthing Aluminum plate is used. (True / False)

7- Mark the statement as true or false. If the statement is false write correct statement-

Statement True/ False Correct statement

Earthquakes occur all the time, all over
the earth.

Bathing should not be avoided during

thunderstorms as bathing is essential for
health.

Best lightning conductor devices are
those which are made up of carbon
compounds rather than metals.

Accumulation of charges in the cloud
may result in lightning

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8- Earth is a rocky planet with a solid and dynamic surface of mountains, canyons, plains and
more. Most of our planet is covered in water. Label the given diagram of the earth with correct
labeling-

9- The outermost layer of the earth is not in one piece. It is fragmented. Each fragment is called
a plate. These plates are in continual motion. Write the name of any three such plates-

1. 2. 3.

10- The plates in the earth may collide and cause disturbance in the earth’s crust. This
disturbance results in an earthquake. Some areas are very sensitive to earthquake.
i- The area where the earthquake is very common are known as-

ii- The power of an earthquake is expressed in terms of a magnitude on a scale called-

iii- The tremors produce waves on the surface of the earth. These are called

iv- Such waves are measured by a graph known as-

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CHAPTER – 16
LIGHT
1- Name the phenomenon shown in the figure-

PHENOMENON:

2- In a phenomenon reflection of light from a surface occur in such a way that a ray incident on
the surface is scattered at many angles rather than at just one angle. Identify the phenomenon
with the help of the given diagram-

3- Louis Braille, himself a visually challenged person, developed a system for visually challenged
persons and published it in 1821. From the given symbol can you make a word-

Option a Option b Option c Option d

RAT MAT CAT BAT

4- Label A, B, C and D and write their role-

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Label Role

A

B

C

D

5- In the dark, we are unable to locate things but owls have excellent night vision. This is
because of pigment rods and cones in their eyes. Which of the statement is correct for night
vision in the owls-
a- More rods and low cones
b- Low cones and low rods
c- Low rods and more cones
d- Equal number of rods and cones
6- A rainbow is a multicolored arc made by light-striking water droplets. The most familiar type
of rainbow is produced when sunlight strikes raindrops in front of a viewer at a precise angle
(42 degrees). Rainbows can also be viewed around fog or waterfalls. A rainbow is an optical
illusion—it does not actually exist in a specific spot in the sky. What is the cause of rainbow
formation?

Answer:

7- Light is falling on surface S1, S2, S3 as shown in Fig.

S1 S2 S3

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Surfaces on which the angle of incidence is equal to the angle of reflection is/are-

Option a Option b Option c Option d

S1 and S2 only S2 and S3 only S1 only All of these surfaces

8- A tiny mirror M is fixed on a piece of cardboard placed on a table. The cardboard is illuminated
by light from a bulb. The position of the eye with respect to the position of the bulb is shown
in Fig. as A, B, C, and D. In which position mirror will be visible? Mark on correct diagram-

9- The given diagram is about image formation. it is incomplete. Complete the diagram-

10- A real image is always inverted whereas a virtual image is always erect. A real image is
formed when the rays of light after reflection or refraction actually meet at some point
whereas a virtual image is formed when the rays of light after reflection or refraction appear
to meet at a point. Identify the real and virtual images in the given diagram-

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CHAPTER- 17
STARS AND THE SOLAR SYSTEM
1- A natural object which is located outside of the Earth's atmosphere like the sun, moon are
called as-

Option a Option b Option c Option d

Asteroid Celestial body Planets Satellite

2- The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System
and the largest and most massive relative to its parent planet, with a diameter about one-
quarter that of Earth. : Moon is visible due to – (name and mark the phenomenon in the
diagram)

Moon SUN

Earth
3- A constellation is an area in space where a group of visible stars forms a specific pattern like
animals, subjects etc. Name the following constellations-

Constellation Name

4- Answer the following questions-

Which is the nearest planet to the Sun?

Which is the farthest planet to the Sun?

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Which two planets show phases like the Moon?

Which two planets have asteroids between them?

Name two artificial satellites of the Earth

What is the speed of light?

Which planet is known as the red planet

5- Fill in the blank with the correct answer-
________________launched India’s first Mars orbiter mission ___________, on November
5, _______. It was successfully placed into an orbit of Mars on September 24 _________.
With this India became the first country in the world to do so in its first attempt.

6- A meteor hit can lead to the death of many living things. If an asteroid the size of an apartment
hits Earth, this blow could possibly destroy a small city. If an asteroid the size of a 20-story
building hits Earth, this blow can completely flatten a small country. Even though many
meteors enter in earth’s atmosphere but very little damage has been reported till now. Give
reason.
Answer:

7- Match the column with I, ii, iii and iv with a column with the alphabet-

8- The following are a few statements. Classify them into two groups namely meteoroid, galaxy
and comet-

It is a small particle from comet asteroids orbiting the sun

It is made up of ice, dust and rocky material

It enters the earth’s atmosphere

It is a collection of billions of stars

It does not enter earth atmosphere

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9- The Solar System is the gravitationally bound system of the Sun and the objects that orbit it.
It formed 4.6 billion years ago. Label the boxes with the correct name of the planets-

1

4
3 2

Number Name of the planet

1

2

3

4

10- An artificial satellite is a man-made satellite used for communication and sending pictures of
the celestial bodies in space.
i- Which is the first Indian artificial satellite –
a- Sputnik
b- Aryabhatt
c- Ramanujan
d- Bhabha
ii- First indigenous satellite of India
a- Aryabhatt
b- Rohini
c- Mandakini
d- INSTA- I

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