CBSE Class 8 Science Long Question And Answers

• Chapter 1 Crop Management LAQs
• Chapter 2 Microorganisms Friend And Foe LAQs
• Chapter 3 Coal And Petroleum LAQs
• Chapter 4 Combustion And Flame LAQs
• Chapter 5 Conservation Of Plants And Animals LAQs
• Chapter 6 Reproduction In Animals LAQs
• Chapter 7 Reaching The Age Of Adolescence LAQs
• Chapter 8 Force And Pressure LAQs
• Chapter 9 Friction LAQs
• Chapter 10 Sound LAQs
• Chapter 11 Chemical Effects Of Electric Current LAQs
• Chapter 12 Some Natural Phenomena LAQs
• Chapter 13 Light LAQs

CBSE Class 8 Science Short Questions And Answers

Chapter 1 Crop Management SAQs
Chapter 2 Microorganisms Friend And Foe SAQs
Chapter 3 Coal And Petroleum SAQs
Chapter 4 Combustion And Flame SAQs
Chapter 5 Conservation Of Plants SAQs
Chapter 6 Reproduction In Animals SAQs
Chapter 7 Reaching The Age Of Adolescence SAQs
Chapter 8 Force And Pressure SAQs
Chapter 9 Friction SAQs
Chapter 10 Sound SAQs
Chapter 11 Chemical Effects Of Electric Current SAQs
Chapter 12 Some Natural Phenomena SAQs
Chapter 13 Light SAQs

CBSE Class 8 Science Short Multiple Choice Questions

• Chapter 1 Crop Management MCQs
• Chapter 2 Microorganisms Friend And Foe MCQs
• Chapter 3 Coal And Petroleum MCQs
• Chapter 4 Combustion And Flame MCQs
• Chapter 5 Conservation Of Plants MCQs
• Chapter 6 Reproduction In Animals MCQs
• Chapter 7 Reaching The Age Of Adolescence MCQs
• Chapter 8 Force And Pressure MCQs
• Chapter 9 Friction MCQs
• Chapter 10 Sound MCQs
• Chapter 11 Chemical Effects Of Electric Current MCQs
• Chapter 12 Some Natural Phenomena MCQs
• Chapter 13 Light Multiple Choice Questions

CBSE Class 8 Science Question And Answers

• Chapter 1 Crop Management Question And Answers
• Chapter 2 Microorganisms Friend And Foe Question And Answers
• Chapter 3 Coal And Petroleum Question And Answers
• Chapter 4 Combustion And Flame Questions And Answers
• Chapter 5 Conservation Of Plants Questions And Answers
• Chapter 6 Reproduction In Animals Question And Answers
• Chapter 7 Reaching The Age Of Adolescence Question And Answers
• Chapter 8 Force And Pressure Question And Answers
• Chapter 9 Friction Question And Answers
• Chapter 10 Sound Question And Answers
• Chapter 11 Chemical Effects Of Electric Current Question And Answers
• Chapter 12 Some Natural Phenomena Question And Answers
• Chapter 13 Light Question And Answers

CBSE Class 8 Science Very Short Questions And Answers

• Chapter 1 Crop Management VSAQs
• Chapter 2 Microorganisms Friend And Foe VSAQs
• Chapter 3 Coal And Petroleum VSAQs
• Chapter 4 Combustion And Flame VSAQs
• Chapter 5 Conservation Of Plants VSAQs
• Chapter 7 Reaching The Age Of Adolescence VSAQs
• Chapter 8 Force And Pressure VSAQs
• Chapter 9 Friction VSAQs
• Chapter 10 Sound VSAQs
• Chapter 11 Chemical Effects Of Electric Current VSAQs
•  Chapter 12 Some Natural Phenomena VSAQs
• Chapter 13 Light VSAQs

CBSE Class 8 Science Activities

• Chapter 1 Crop Management Activities
• Chapter 2 Microorganisms Friend And Foe Activities
• Chapter 4 Combustion And Flame Activities
• Chapter 6 Reproduction In Animals Activities
• Chapter 7 Reaching The Age Of Adolescence Activities
• Chapter 8 Force And Pressure Activities
• Chapter 9 Friction Activities
• Chapter 10 Sound Activities
• Chapter 11 Chemical Effects Of Electric Current Activities
• Chapter 12 Some Natural Phenomena Activites
• Chapter 13 Light Activities

CBSE Class 8 Science Chapter 8 Force And Pressure Fill In The Blanks

Question 1. To draw water from a well, we have to use the _____________ rope.
Answer: Pull

Question 2. A charged body _____________ an uncharged body.
Answer: Attracts

Question 3. To move a loaded trolley, we have to do it.
Answer: Push

Question 4. The north pole of a magnet _____________ the north pole of another magnet.
Answer: Repels

Question 5. An archer stretches her bow while aiming at the target. She then releases the arrow, which begins to move towards the target. Based on this information, fill up the gaps in the following statements using the following terms: muscular, contact, non-contact, gravity, friction, shape, attraction

Question 6. To stretch the bow, the archer applies a force that causes a change in its ___________.
Answer: shape

Question 7. The force applied by the archer to stretch the bow is an example of a ___________ force.
Answer: muscular

Question 8. The type of force responsible for a change in the state of motion of the arrow is an example of a ___________ force.
Answer: Contact

Question 9. While the arrow moves towards its target, the forces acting on it are due to ___________ and that due to the ___________ of air.
Answer: Gravity, friction.

Question 10. The ____________ the area, the larger the pressure on a surface.
Answer: Smaller

Question 11. A cyclist exerts a force of ____________ on the pedal of the cycle.
Answer: Push

Question 12. When two forces act in the same direction, then the net force acting is ____________ of the two forces.
Answer: Sum

Question 13. The force that acts when two objects are in actual contact is called _the ___________ force.
Answer: Contact

Question 14. Halting of the moving ball on its own is an example of ____________ force.
Answer: Frictional

Question 15. As we go high on the mountain, the ____________ decreases.
Answer: Pressure

Question 16. If the force is applied on a smaller area of contact, then the pressure exerted by it ____________.
Answer: Increases

Question 17. Draper and rubber sucker work on the principle of ____________ pressure.
Answer: Atmospheric

Question 18._________ is an example of contact force.
Answer: Frictional Force

Question 19. When you kick a ball with your leg, you exert _______ force.
Answer: Muscular

Question 20. _______ is the device used to measure atmospheric Pressure.
Answer: Barometer

Class 8 Science Chapter 8 Force And Pressure True Or False

Question 1. If two forces act in opposite directions, then the net force is the difference between the two forces.
Answer: True

Question 2. In ‘tug of war’, when both teams apply equal pulling force, then the net force is maximum.
Answer: False

Question 3. The force between two electric charges is called the magnetic force.
Answer: False

Question 4. Muscular force and frictional force are examples of non-contact forces.
Answer: False

Question 5. The force per unit area is the pressure on that area.
Answer: True

Question 6. The nails penetrated the planks easily because a large force acts on a small area.
Answer: True

Question 7. Water comes out more slowly from an upstairs tap than from a similar downstairs tap.
Answer: True

Question 8. The blood pressure in our body balances the atmospheric pressure acting on our body.
Answer: True

Question 9. The SI unit of pressure is the newton.
Answer: False

Question 10. Pressure is defined as the force per unit length.
Answer: False

Question 11. A liquid exerts pressure in all directions.
Answer: True

Class 8 Science Chapter 8 Force And Pressure Match The Columns

Question 1. Match Column 1 with Column 2.

Answer: (a)-(4), (b)-(3), (c)-(1), (d)-(2), (e)-(6), (f)-(5)

Class 8 Science Chapter 8 Force And Pressure

The following questions consist of two statements: Assertion (A) and Reason (R). Answer these questions by selecting the appropriate option given below

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.

Question 1.

Assertion (A) A Push or pull on an object is called a force.
Reason (R) Forces add together if they are applied in opposite directions.

Answer: 3. A is true, but R is false because forces applied in the same direction add together.

Question 2.

Assertion (A) In the game of tug of war, sometimes the rope does not seem to move to any side even if strong forces are applied from both sides.
Reason (R): Equal forces applied from opposite sides on an object make the net applied force zero.

Answer: 1. Both statements are correct. If the net force on a body is zero, then it does not move. Hence, the correct option is (a).

Question 3.

Assertion (A): Electrostatic force is a contact force.
Reason (R) The force exerted by a charged body on another charged body is known as the electrostatic force.

Answer: 4. A is false because electrostatic force is a non-contact force. Hence, option (d) is correct.

Question 4.

Assertion (A) The larger the area, the smaller the pressure.
Reason (R) The force acting on a unit area of a surface is called pressure.

Answer: 1. According to the definition of pressure,

⇒ \(\text { Pressure }=\frac{\text { Force }}{\text { Area }} \Rightarrow \text { Pressure } \propto \frac{1}{\text { Area }}\)

Both statements are correct. Hence, option (a) is correct

Class 8 Science Chapter 8 Force And Pressure Assertion-Reason Questions And Answers

The following questions consist of two statementsAssertion (A) and Reason (R). Answer these questions by selecting the appropriate option given below.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A
3. A is true, but R is false.
4. A is false, but R is true.

Question 10.

1. Assertion (A) Fruit falls on the ground when it gets detached from the tree.
2. Reason (R) The force responsible for this action is the electrostatic force.

Answer: 3. A is true, but R is false.

Question 11.

1. Assertion (A) A football rolling along the ground gradually slows down and finally comes to rest.
2. Reason (R) This happens due to the force of friction between the ball and the ground.

Answer: 1. Both A and R are true, and R is the correct explanation of A.

CBSE Class 8 Science Chapter 1 Crop Management Multiple Choice Questions

Question 1. Which of the following sorts?

1. Rice, wheat, cotton
2. Mize, soybeans, mustard
3. Rice, mustard, cotton
4. Rice, maize, soybeans

Answer: Rice, wheat, cotton

Question 2. The monsoon in our country during the months

1. A pill in December
2. June September
3. November March
4. January may

Answer: June, September

Question 3. The pictures below display two techniques.

What are the advantages of choosing a sprinkler system over a pulley system for irrigation?

1. Sprinkler system reduces the wastage of water
2. Sprinkler system decreases the water requirement of the crops
3. Sprinkler system increases the water absorption capacity of the crops
4. A sprinkler system provides excess water to the crops for high productivity

Answer: A Sprinkler system reduces the wastage of water

Question 3. Which one of the following conditions is not essential for growing maize?

1. High Temperature
2. Humidity
3. low temperature
4. Rainfall

Answer: Low temperature

Question 4. The process of loosening and turning of Soli is called

1. Litigation mid-managing,
2. Digging mid-winnowing
3. Tilling mid-ploughing
4. Harvesting mid-storage

Answer: Tilling mid-ploughing

Question 5. Which of the following tools would a farmer use to remove weeds from the field?

1. Hoe
2. Plough
3. Axe
4. Cultivator

Answer: Hoe

Question 6. The planting of seeds in the soil is called

1. Cultivation
2. Irrlgation
3. Harvesting
4. Sowing

Answer: Sowing

Question 7. A seed drill is used to

1. Snow the seeds
2. Remove the weeds
3. Remove the pest
4. Mix manure into the soil

Answer: Snow the seeds

Question 8. A former aim was to enhance the soil nutrients in Ills field without using chemical fertilisers. What natural method should he consider for replenishing the soil?

1. Sowing healthy seeds
2. Growing the same crops every year
3. Growing different crops alternatively
4. Supplying water to crops at regular intervals

Answer: Growing different crops alternatively

Question 9. Which of the following syntomonts is not true for organic manure?

1. It enhances water water-holding capacity of the soil
2. It has a balance of all plant nutrients
3. It provides humus to soli
4. It improves the texture ofsoil

Answer: It has a balance of all plant nutrients

Question 10. Which of the following is not true for fortelisers?

1. They increase the yield
2. Their exterior use disturbs the balance of nutrients in till’ Nllll
3. They provide a lot of humus for the soil
4. They need not be environment-friendly

Answer: They provide a lot of humus to the soil

Question 11. Read the statement given below.

1. Seeds require moisture for germination.
2. Plants can absorb nutrients mostly in dissolved form.
3. Irrigation protects crops from both frost and hot air currents.
4. Irrigation improves soil texture

Answer: Irrigation protects crops from both frost and hot air currents.

Choose the combination of statements that includes the need to irrigate crops.

1. (1) and (2)
2. (1) and (3)
3. (1), (2), and (4)
4. (1) and (3)

Question 12. Waiting for the crops at regular Intervals Is called

1. Sowing
2. Manuring
3. Tilling
4. Irrigation

Answer: Irrigation.

Question 13. Consider the following list of food Items

1. Honey
2. Wheat
3. Sunflower oil
4. Eggs
5. Fish oil
6. Beans
7. Pulses
8. Cheese
9. Milk
10. Apple

Which choice categorizes sources of the food Items correctly?

Answer: 4. Eggs

CBSE Chapter 1 Crop Management Long Answer Questions

Question 1. Soham investigates the water holding capacity of four different types of soils. He sets up an experiment for each type of soil as shown in the diagram. Soham records his observation in a table.

Question 2. Which type of soil absorbs the most water?

1. Clay
2. Loam
3. Sand
4. Silt

Answer: Clay

Soham added the same amount of water to each type of soil. State one more thing that Soham needs to keep the same in his experiment.

Answer: The amount of each soil type on the filter paper must remain the same for the experimental setup

Question 2. Paddy is a major cereal crop in our country.

1. In which season is paddy cultivated?
2. Discuss the method of sowing.
3. What measures must be taken to prevent the spoilage and insect attack of harvested grains?

Answer:

1. Paddy is cultivated in the rainy season as it is a Kharif crop
2. For sowing paddy, seeds are first grown in a nursery, and later, seedlings are transplanted. In the field. This allows us to select only healthy and better seedlings for cultivation
3. Measures taken to prevent the spoilage or damage of harvested crops from insect attack are
   1. Exposing them to sunlight for drying, as freshly harvested crops have moisture.
   2. Dried neem leaves are kept with stored grains to prevent damage from pests.
   3. Specific chemical treatments are also available for preventing crops from spoilage and insect attacks

Question 3. Explain various agricultural practices in a sequential manner
Answer: Various agricultural practices are as follows

Preparation of soil. The first step is the preparation of the soil. In this, the soil is loosened and turned up. It helps the plants to grow and develop. The process of loosening and turning the soil is called tilling or ploughing. Sometimes manure is also added to the soil before tilling.

Sowing After preparation of the soil, the second step, called sowing, takes place. It is the process of scattering or planting seeds into the soil before sowing good Good-quality seeds are selected. The seeds should be clean and healthy.

Adding manure and fertiliser soil supplies minerals and nutrients to the crops. These nutrients are essential for the growth of plants. Sometimes these nutrients are lacking, so substances are added to maintain or replenish the soil. These substances are called manure and fertilisers. Manures and fertilisers are essential to increase crop production

Irrigation: The process of watering the crop plants at regular intervals is called Irrigation. Plants take all the nutrients and minerals in dissolved form. So, water is most essential for the germination of seeds, growth, and development of plants.

Harvesting After maturation, the crop is cut off. This process is called harvesting. It is done by a sickle or by a machine called a harvester.

Storage of the product is one of the most important tasks. To keep the grains for longer, they should be safe from moisture, pests, insects, and other microorganisms.

Question 4. As a part of the eco-club activity, students were asked to raise a kitchen garden on the school premises. They were provided with some materials given in the box. List the other materials you would require. How will you plan the garden? Write the steps.

Khurr: water-can, spade, shovel

Answer:

Besides the given tools, the other items required for raising a garden are seeds and seedlings of vegetables, plants from a nursery, kitchen waste, manure, water, soil, etc.

Steps for raising the garden.

1. Kitchen waste will be collected and composted in a pit.
2. A patch of land will be identified for the garden.
3. Soil will be dug up and levelled with the help of a spade.
4. Sowing of seeds/ transplanting of seedlings will be done at an even distance.
5. Seeds/seedlings are selected as per the season. Water the plants regularly with a watering can.
6. Compost or manure will be applied.
7. Weeds will be removed periodically with the help of Kliurpi.

Question 5. You must have heard farmers talking about soil fertility. What is it? Mention some methods by which the soil fertility can be replenished.
Answer: The ability of soil to supply all the essential plant nutrients to a crop in adequate quantity is called soil Fertility. Repeated growing of crops in the same soil removes various nutrient elements from the soil, due to the soil lose its fertility.

1. The soil fertility can be replenished or regained by the following methods
2. By putting manure and fertiliser in the soil.
3. By practising crop rotation.
4. By growing leguminous plants or crops like pulses, peas, beans, groundnut, etc..

CBSE Chapter 1 Crop Management Short Answer Questions

Question 1. Classify the following crops into Kharif and Rabi crops and write in the tabular column given below. Maize, paddy, mustard, pea, gram, wheat, groundnut

Answer: From the above given crop list, the Kharif and Rabi Crops can be grouped as

Question 2. The levelling of a ploughed field is beneficial. Give reasons to support your
Answer: The levelling of a ploughed field is beneficial for the following reasons

1. It helps in the uniform distribution of water in the fields during irrigation.
2. It also prevents loss of moisture from the ploughed soil.
3. It ensures ever germination and uniform growth of crops.

Question 3. Beera wants to practice crop rotation in his field. Suggest a Rabi crop and a Kharif crop that will replenish his field with nitrogen. Which crop replenishes nitrogen and why?
Answer: Rabi crops are pea and grain, while Kharif crops are soybean. These are grown in different seasons and therefore can very well be rotated alternately. Pea and soybean are leguminous plants that harbour bacteria, i.e., Rhizobium, in their root nodules.

These bacteria convert atmospheric nitrogen into a usable form for plants. These nitrogen-fixing plants can replenish nitrogen in the field, and hence, Beera can easily practice crop rotation.

Question 4. Leguminous plants do not require nitrogenous fertilisers. Why Is It so?
Answer: The planting of a leguminous crop in a field has the same effect as adding nitrogenous fertiliser in the field. They can fix atmospheric nitrogen themselves by using nitrogen-fixing bacteria in their root nodules. Therefore, nitrogenous fertilisers are not required for growing leguminous plants.

Question 5. State two advantages of using chemical fertilisers over manure. What would happen if fertilisers are used in excess?
Answer: Advantages of using chemical fertilisers over manure

Fertilisers are nutrient-specific and provide specific nutrients to the oil in the desired quantity.

These being readily soluble in water can he absorbed easily by the crop plants.

If it is used in excess, it causes tremendous changes in the chemical nature of the soil and makes it less fertile.

Question 6. Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.

Answer: Flow chart for the crop production of sugarcane

Question 8. Explaining how to go to the continuous plantation of crops in the field.
Answer: Soil supplies mineral nutrients to the crop. These mineral nutrients are essential for the growth of plants. If crops are grown continuously in the same field for a long period, lie soil becomes poorer in nutrients. Titus, the soil gets deficient in nutrients, and the field becomes infertile.