WBBSE Solutions For Class 6 School Science Chapter 6 Primary concept Of Force and Energy MCQs

Chapter 6 Primary Concept Of Force And Energy Review Questions Environment Review Questions MCQs

Question 1. SI unit of force is

  1. Dyne
  2. Kg
  3. Newton
  4. None of these

Answer: 3. Newton

Question 2. Magnet attracts

  1. Iron nails
  2. Eraser
  3. A plastic scale
  4. Wooden pencil

Answer: 1. Iron nails

Read And Learn More: WBBSE Solutions For Class 6 School Science

Question 3. Force can change a body.

  1. Mass
  2. Weight
  3. Density
  4. Shape

Answer: 4. Shape

Question 4. SI unit of weight is

  1. Gram
  2. Dyne
  3. Density
  4. Shape

Answer: 4. Shape

Class 6 Science Question Answer WBBSE

Question 5. An object that has kinetic energy must be

  1. Lifted above the earth’s surface
  2. In motion
  3. At rest
  4. None of the above

Answer: 2. In Motion

Question 6. As height increases, so does

  1. Thermal energy
  2. Chemical energy
  3. Atomic energy
  4. Potential energy

Answer: 4. Potential energy

Question 7. _________ is a non-magnetic substance.

  1. Wood
  2. Cobalt
  3. kg
  4. Newton

Answer: 1. Wood

Question 8. Which is the major advantage of using sources such as sunlight, wind, and running water instead of fossil fuels, such as coal and natural gas?

  1. Sunlight, wind, and running water are much more efficient than fossil fuels
  2. Sunlight, wind, and running water are renewable and available indefinitely
  3. Sunlight, wind, and running water are much less expensive to use than fossil fuels
  4. Sunlight, wind, and running water can be used at any geographical location

Answer: 2. Sunlight, wind, and running water are renewable and available indefinitely

Question 9. When a boat sail forward, it uses

  1. The frictional force of air
  2. The potential energy of air
  3. The kinetic energy of air
  4. The chemical energy of air

Answer: 4. Chemical energy of air

Question 10. Man is ___________ but cow is

  1. Herbivore, omnivore
  2. Omnivore, herbivore
  3. Carnivore, herbivore
  4. Omnivore, carnivore

Answer: 2. Omnivore, herbivore

Class 6 Science Question Answer WBBSE

Question 11. If a football is rolled on the field, it stops after traveling through a certain distance. The responsible factor for this incident is

  1. Mass of the ball
  2. The shape of the ball
  3. Force of friction
  4. Force of gravity

Answer: 3. Force of friction

Question 12. Which of the following food chain is not correct?

  1. Grass Grasshopper→→Toad→Snake Mongoose
  2. Leaf of plant→→→Locust→→Myna
  3. Leaf of plant->Rabbit->Hawk T2300
  4. Grass Dear→Giraffe

Answer: 4. Grass Dear→Giraffe

Question 13. The food you eat and fossil fuels are both examples of this form of energy.

  1. Atomic energy
  2. Thermal energy
  3. Chemical energy
  4. Mechanical energy

Answer: 3. Chemical energy

Class 6 Science Question Answer WBBSE

Question 14. What device among the following converts chemical energy to mechanical energy?

  1. Human
  2. Car
  3. Jetski
  4. All of these

Answer: 4. All of these

Question 15. Which of the following is the best example of increasing an object’s potential energy?

  1. Rolling a bowling ball
  2. Turning on a light bulb
  3. Dropping a light bulb
  4. Stretching a rubber band

Answer: 4. Stretching a rubber band

Question 16. Which one is a primary consumer?

  1. Grass
  2. Goat
  3. Tiger
  4. Vulture

Answer: 2. Goat

Question 17. Energy flow in an ecosystem is

  1. Unidirectional
  2. Bidirectional
  3. Multidirectional
  4. Reversible

Answer: 1. Unidirectional

Class 6 WBBSE Science Question Answer

Question 18. On which surface will a toy sled travel the furthest?

  1. Rock
  2. Carpet
  3. Polished wood
  4. Ice

Answer: 4. Ice

Question 19. Energy transfer from one trophic level to another in a food chain is

  1. 1%
  2. 10%
  3. 2%
  4. 20%

Answer: 2. 10%

Question 20. Potential energy is

  1. Stopped energy
  2. Thermal energy
  3. Stored energy
  4. Moving energy

Answer: 3. Stored energy

Question 21. All forms of energy which are available on earth have their origin from

  1. The chlorophyll
  2. The sun
  3. The nuclear fission
  4. The tides

Answer: 2. The sun

Question 22. The beating of a drum with sticks produces ___________ from ___________

  1. Sound energy, mechanical energy
  2. Mechanical energy, sound energy
  3. Sound energy, electrical energy
  4. Sound energy, heat energy

Answer: 1. Sound energy, mechanical energy

Question 23. Magnetic attraction is a type of

  1. Frictional force
  2. Gravitational force
  3. Contact force
  4. Non-contact force

Answer: 4. Non-contact force

Class 6 WBBSE Science Question Answer

Question 24. In an ecosystem, if there are 40,000 kg of producers, how many kg of tertiary consumers are there?

  1. 4 kg
  2. 40 kg
  3. 400 kg
  4. 4000 kg

Answer: 2. 40 kg

Question 25. What type of energy is produced at the time of clapping?

  1. Sound energy
  2. Chemical energy
  3. Magnetic energy
  4. All of these

Answer: 1. Sound energy

Question 26. Between two balls weighing 10 kg and 20 kg, which one would experience more friction?

  1. 10 kg ball
  2. 20 kg ball
  3. Same for both
  4. None of the above

Answer: 2. 20 kg ball

Question 27. Kicking a football is

  1. Pull
  2. Push
  3. Impulse
  4. Throw

Answer: 3. Impulse

Question 28. An example of a renewable source of energy is

  1. Coal
  2. Natural gas
  3. Petroleum
  4. Tidal energy

Answer: 4. Tidal energy

Question 29. Blowing of electric horn involves the transformation of

Class 6 WBBSE Science Question Answer

  1. Mechanical energy to sound energy
  2. The heat energy to sound energy
  3. Electrical energy to sound energy
  4. Chemical energy to sound energy

Answer: 3. Electrical energy to sound energy

Question 30. An example of force without touch is

  1. Nuclear force
  2. Magnetic attraction
  3. electrostatic repulsion
  4. all of these

Answer: 4. All of these

Chapter 6 Primary Concept Of Force And Energy Fill In The Blanks

Question 1. Cobalt and magnet __________ each other.
Answer: Attract

Question 2. Coal, petroleum, and natural gases are known as __________ energy.
Answer: Non-renewable

Question 3. The gravitational force acting on a body is called it’s __________
Answer: Weight

Question 4. While closing the zip of your school bag, you apply __________ force.
Answer: Pulling

Question 5 The smoother the surface, the less the __________
Answer: Friction

Question 6. Energy flow in the ecosystem is __________
Answer: Unidirectional

Question 7. Interconnected food chains are called __________ __________.
Answer: Food web

Question 8. Only __________ % of energy is taken at each trophic level of the energy pyramid.
Answer: 10

Class 6 WBBSE Science Question Answer

Question 9. Complete the food chain Paddy Rat→ __________ →Hawk.
Answer: Snake

Question 10. The object which changes its position with respect to time is called a ______________object.
Answer: Moving

Question 11. The capacity of a body to do work is called __________.
Answer: Energy

Question 12. __________ and __________ energy are forms of mechanical energy.
Answer: Potential, Kinetic

Question 13. __________ converts solar energy into electrical energy.
Answer: Solar Photovoltaic Cells

Question 14. During photosynthesis, __________ energy is transformed into energy.
Answer: Light, Chemical

Question 15. The lowest trophic level of the food pyramid is composed of __________
Answer: Producers

Chapter 6 Primary Concept Of Force And Energy Identify As True Or False

Question 1. Aluminum and copper are magnetic substances.
Answer: False

Question 2. Friction acts in the same direction as the impressed force which causes motion.
Answer: False

Question 3. Wind and tidal energy are renewable sources of energy.
Answer: True

Question 4. In the Sl system, a unit of force is done.
Answer: False

WBBSE Class 6 Science Question Answer

Question 5. Friction is associated with disadvantages only.
Answer: False

Question 6. Most forms of energy can be converted into other forms of energy.
Answer: True

Question 7. Green plants belong to the tertiary trophic level of the food chain.
Answer: False

Question 8. Running water produces hydel energy.
Answer: True

Question 9. The description of motion is independent of the location of the viewer.
Answer: False

Question 10. If friction is absent, a moving ball shall continue to roll forever along a straight line.
Answer:

Question 11. Push can act through the non-rigid connector.
Answer: False

Question 12. There are 8 forms of energy prevalent in nature.
Answer: True

Question 13. Push and pull are contact forces.
Answer: True

Question 14. The apex of the food pyramid involves more energy than the base.
Answer: False

Question 15. Wood is a type of non-renewable source of energy.
Answer: True

Chapter 6 Primary Concept Of Force And Energy Match The Columns

WBBSE Solutions Class 6 School Science Chapter 6 Primary Concept Of Force and Energy Math the Columns
Answer: A-1,B-3,C-4,D-2

WBBSE Solutions Class 6 School Science Chapter 6 Primary Concept Of Force and Energy Math the Columns table 2
Answer: A-4,B-1,C-2,D-3

WBBSE Solutions Class 6 School Science Chapter 6 Primary Concept Of Force and Energy Math the Columns table 3
Answer: A-3,B-4,C-2,D-1

WBBSE Solutions Class 6 School Science Chapter 6 Primary Concept Of Force and Energy Math the Columns table 4
Answer: A-5,B-1,C-2,D-4

Chapter 6 Primary Concept Of Force And Energy Answer In Words Or A Sentence

Question 1. What % of energy is absorbed in each trophic level?
Answer: 10% energy.

Question 2. Does friction depend on the area of the surface in contact with each other?
Answer: No.

Question 3. How is each food level in a food pyramid known?
Answer: Trophic level.

WBBSE Class 6 Science Question Answer

Question 4. Who formulated the concept of the 10 percent law?
Answer: Raymond Lindemann.

Question 5. What is the unit of weight in the CGS system?
Answer: Dyne.

Question 6. Which one is more stable-food chain or the food web?
Answer: Food web.

Question 7. Give an example where chemical energy is transformed into heat, light, and sound energy.
Answer: Bursting of cracker.

Question 8. Give two examples of fossil fuels.
Answer: Coal and petroleum.

Question 9. What type of force is involved while we take out a drawer?
Answer: Pull.

Question 10. What do the animals which live on plants known as?
Answer: Herbivores.

Question 11. Choose the odd one out-tiger, dog, cow, leopard.
Answer: Cow (herbivores); others are carnivores.

Question 12. Sort out the magnetic substance-wood, plastic, kerosene, cobalt.
Answer: Cobalt.

Question 13 Mention two devices that convert solar energy.
Answer: Solar cooker and solar lantern.

Question 14. What is the SI unit of friction?
Answer: The SI unit of friction is Newton.

Question 15. State the type of energy transfer that occurs when window panes break due to an explosion.
Answer: Chemical energy to mechanical energy.

Question 16. State the type of energy transfer that occurs when we hear a radio broadcast of a cricket match.
Answer: Electrical energy to sound energy

Question 17. Which organisms come last in each trophic level?
Answer: Detrivores and decomposers (ex: Dung beetles, fungi, bacteria, etc.)

Question 18. Which trophic level consists of the greatest number of organisms?
Answer: First trophic level or Producers.

Question 19. What is the force that is responsible for wearing out of bicycle tires?
Answer: Frictional force of road.

Question 20. What is the direction of the force of friction acting on a moving object?
Answer: Opposite to the direction of motion.

Chapter 6 Primary Concept Of Force And Energy Short Answer Type Questions

Question 1. Arrange in order: rain, water, cloud, vapor.
Answer: Water vapour→ cloud→rain.

Question 2. Give an example where the force of friction is advantageous to us and explain it.
Answer: Friction helps us in walking. When a man walks, he lifts one leg up, leans forward, and with the other leg presses the ground in a slightly inclined fashion in the backward direction.

The pressing of the leg is balanced by the frictional force of the ground, otherwise, he will slip and fall forward on his face. Thus friction prevents him from slipping.

WBBSE Class 6 Science Question Answer

Question 3. Current is drawn from the following devices(a) a Generator and (b) A dry cell. State the energy transformation taking place in each case.
Answer:

  1. In a generator, mechanical energy changes into electrical energy.
  2. A dry cell converts the stored chemical energy into electrical energy.

Question 4. How do contact forces act?
Answer: Contact forces are to be applied through something rigid or non-rigid. Push is applied through something rigid while a pull can act through a non-rigid connector, such as a rope or a wire.

Question 5. What is mechanical energy?
Answer: Kinetic and potential energies are together known as mechanical energy. It is the energy associated with the motion and position of an object.

Question 6. What is the water cycle?
Answer: The water cycle is the cycle of processes by which water circulates between the earth’s water bodies, atmosphere, and land involving evaporation, transpiration, condensation, and precipitation.

Question 7. What are the causes of the energy crisis?
Answer: The causes of the energy crisis may be briefly summarised as

  1.  Increase in population and rapid urbanization leading to overconsumption
  2.  Increase in automobiles
  3. Growing needs of industries and mechanized agriculture.
  4. The decline of stored fossil fuels.
  5. Poor infrastructure, flaws in the distribution network, and wastage
  6. Miscellaneous factors like war, natural calamities, etc

Question 8. What are magnetic substances?
Answer: Materials that can be magnetized and which are strongly attracted to a magnet are called magnetic substances. These include iron, cobalt, lodestone, etc.

Question 9. Arrange the following organisms in the correct sequence from producer to secondary consumer
Kingfisher-algae-fish.
Answer: The correct sequence shall be-
algae (producer) fish (primary consumer) → kingfisher (secondary consumer).

Question 10. Suppose you are traveling in a bus or train. When the bus or train is in motion, which objects would appear to be at rest to you?
Answer: When an observer is inside a moving train, then the compartment itself along with its fixed components (such as berths, seats, window frames, etc.) and the passengers who are seated inside the compartment shall appear stationary to the observer.

Question 11. Name a force that causes the dissipation of energy. On what factors does this force depend?
Answer: Friction causes the dissipation of energy in the form of heat.

The factors on which friction depends are:

  1. Friction depends on the material and the nature of the surfaces in contact and their state of polish.
  2. Friction depends upon the mass of the body because that in turn determines how the surfaces in contact are pressed together.

Question 12. Friction is independent of area. But brakes of very small contact areas are not used. Why?
Answer: It is true that friction does not depend on the area of contact but it causes a lot of wear and tear.

WBBSE Class 6 Science Question Answer

Thus brakes have to be built with appreciable contact areas to avoid wear and tear and to increase the life span of the brake shoe or pad.

Chapter 6 Primary Concept Of Force And Energy Long Answer Type Questions

Question 1. Define force. What is its unit in the Sl system? State any two effects of force.
Answer: A force may be defined as an external cause that changes or tends to change the state of rest or of the uniform motion of a body in a straight line.

In the Sl system, the unit of force is called Newton. Two effects of force are

1. It can set a stationary body into motion.
A railway engine can move a stationary train by applying a pull or push.

2. It can stop a moving body.
A speeding car is stopped by the application of brakes.

Question 2. ‘Sun is the ultimate source of all energies available on earth’ discuss.
Answer: When a man walks, he lifts one leg up, leans forward, and with the other leg presses the ground in a slightly inclined fashion in the backward direction.

Question 3. What is a pyramid of energy? Why is there the highest amount of energy at the base and the lowest at the apex of an energy pyramid?
Answer: The Push is applied through something rigid while a pull can act through a non-rigid connector, such as a rope or a wire.

Question 4. What is friction? Give examples (one each) of the following
1. friction produces heat
2. friction causes wear and tear of mating surfaces.
Answer:

1. Friction produces heat:

  1. When two palms are rubbed together, they become warm.
  2. If a stone is rubbed on a metallic surface for some time, the metal becomes hot.
  3. When we want to ignite a matchstick, we rub the stick on the rough surface of a matchbox.

The rough surface of the matchbox and the head of the matchstick both contain gunpowder on them. Rubbing causes the temperature to increase and heat is produced which ignites the matchstick.

2. Friction causes erosion of contact surfaces:

1. The tires of cars or cycles get eroded after a long run.

Question 5. State the differences between renewable and non-renewable sources of energy.
Answer:

WBBSE Solutions Class 6 School Science Chapter 6 Primary Concept Of Force and Energy Renewable source and Non-renewable source

Question 6. Explain the 10 percent law in connection with the energy pyramid.
Draw a food chain with respect to energy flow in a commonly formed ecosystem formed of the organisms named below
(1) Hawk (2) Grasshopper (3) Grass (4) Snake (5) Toad.
Answer: According to the 10 percent law, about 10% of total energy is transmitted during energy flow through several trophic levels to be used up for building the body mass, and rest is dissipated as heat energy.

For example, 100 kg biomass in the grass will make 10 kg biomass for herbivorous animals (ex. deer) and 1 kg Primary Concept of Force and Energy Grass Grasshopper→Toad Snake→Hawk.

Question 7. When a ball is thrown vertically upward, how do its potential and kinetic energy change?
Answer: At the moment when the ball is thrown, it has only kinetic energy due to an upward velocity. As it attains height, it loses kinetic energy because its velocity decreases and gains potential energy.

WBBSE Class 6 Science Question Answer

At the highest point of ascent, the ball stops momentarily possessing potential energy only. During descent, it loses potential energy and gains kinetic energy as its velocity increases with time.

Just before touching the ground, the ball possesses kinetic energy only.

Question 8. A solar cooker is turned ON. Which type of energy conversion is taking place here? Name two possible measures to mitigate the global energy crisis.
Answer: When a solar cooker is turned ON, light energy is converted into heat energy.
Two steps to mitigate the global energy crisis:

1. Higher utilization of renewable types of energy in a planned manner.

2. Prevention of wastage of energy in daily urban life.

Question 9. How does the transfer of energy take place in the water cycle?
Answer: Solar energy causes surface water to undergo evaporation to become water vapor. As the water vapor attains height it gains potential energy.

Once water vapor is in the upper part of the atmosphere, it releases heat to the surrounding colder air to either condense into liquid or form ice crystals.

Air currents move the clouds across the planet. The water droplets in clouds collide with other droplets to form larger droplets and undergo precipitation as rain or snowfall under the influence of gravity.

As it falls it gains kinetic energy. Kinetic energy drives runoff water that flows downhill through streams, rivers, and lakes.

Some of the water eventually reaches the oceans and again participates in the water cycle.

Thus it is self-renewing and continuous and the sun provides all the energy to cause the change of states through the processes of melting, sublimation, evaporation, freezing, condensation, and deposition.

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