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| Physics 9th Chapter 6 Work and Energy Questions Bank |
Physics 9th Chapter 6 Work and Energy Questions Bank MCQs
Choose the right answer
1. 1 hp =
2. 1120 watts are equal to
3. A bowler during playing cricket throws a ball of mass 200 g with a velocity of 20 ms⁻¹. Its kinetic energy will be:
4. A motor lift a weight of 5N up to the height of 2m in 4s. What will be the power of the motor?
5. Ability of a body to do work due to its height from the surface of earth is called energy:
6. Ability of a body to do work due to its position is called:
7. Ability of a body to do work is known as:
8. Basic kinds of mechanical energy:
9. Decrease in K.E is equal to:
10. Decrease in P.E is equal to:
11. Energy is quantity:
12. Energy of the water stored in the dam is:
13. Energy possessed by a ball when it is lifted to a height ‘h’ from the ground:
14. Energy possessed by a body due to its motion is called?
15. For maintaining the body temperature energy is used:
16. For movement of our body energy is used:
17. For the propagation of signals in our body energy is used:
18. For work ___ conditions should be fulfilled:
19. How many types of mechanical energy are?
20. How much power is used by a 40 kg athlete by climbing 10m high ladder in 10 s:
21. Increase in K.E is equal to:
22. Increase in P.E is equal to:
23. One Mega joule is equal to:
24. Product of force and distance covered in the direction of force is:
25. Rate of doing work with respect to time is known as:
26. There are ___ basic kinds of energy:
27. Total energy of the system:
28. Unit of Energy in System International is
29. Unit of power is:
30. Unit of work is:
31. What is efficiency of electric fan?
32. What is efficiency of electric motor?
33. What is efficiency of Petrol engine?
34. What is efficiency of solar cell?
35. What is young modulus of Aluminum?
36. What will be efficiency if input is 100 g and output is 55 j?
37. What will be the kinetic energy of a body if its mass is doubled?
38. What will be the kinetic energy of a body if its velocity is doubled?
39. What will be the kinetic energy of a car of mass 1000 kg moving with a velocity of 20 ms⁻¹?
40. What will be the magnitude of work if a force of 25 N pulls a stone through a distance of 5 m in its direction?
41. What will be the power of a machine doing 10 J work in 5 seconds?
42. When a ball is lifted to a height `11' from the ground, it will possess energy:
43. Which unit is equal to kgm²5-2 in the units given below?
44. Work done will be _____ if no force act on the body:
45. Work done will be maximum if displacement is ----- to force:
46. Work done will be one____if a force of one Newton acts on the body and it covers the distance of 1 meter in the direction of force:
47. Work done will be zero if displacement is-----to force:
48. Work is quantity:
Short Questions
"1. A crate is moved by pulling the rope attached to it. It moves 10 m on a straight horizontal road by a force of 100 N. How much work will be done if?
The rope is parallel to the road
The rope is making an angle of 300 with the road."
2. Define Elastic Potential Energy.
3. Define Energy and write down its unit.
4. Define energy, give two types of mechanical energy.
5. Define Gravitational Potential Energy.
6. Define the ideal system. Why is it not possible to construct 100 percent efficient system?
7. Define watt.
8. Define work. What is its SI unit?
9. Describe electrical energy with examples?
10. Describe heat energy with examples?
11. Describe light energy with examples?
12. Describe mechanical energy with examples?
13. Describe nuclear energy with examples?
14. Describe sound energy with examples?
15. Describe the harmful waste products released by fossil fuels?
16. Describe the process by which energy is converted from one form to another concerning fossil fuel energy?
17. Describe the process of electricity generated by biomass?
18. Describe the process of electricity generated by geothermal energy?
19. Describe the process of electricity generated by solar cells?
20. Describe the process of electricity generated by wind energy?
21. Describe the processes by which energy is converted from one form to another concerning nuclear fuels?
22. How can you find the efficiency of a system?
23. How energy is obtained from the sun?
24. How energy is obtained from water?
25. How much power is used by a 40 kg athlete by climbing 10m high ladder in 10s?
26. List non-renewable sources of energy?
27. List the environmental issues associated with nuclear fuels?
28. Name a device that converts mechanical energy into electrical energy.
29. Name five devices that convert electrical energy into mechanical energy.
30. State mass-energy equation E = mc².
31. The kinetic energy of a body of mass 2 kg is 25 J. What will be its speed?
32. What is Efficiency? Write its formula and unit (if any)
33. What is meant by the efficiency of a system?
34. What is meant by the term power?
35. What is Power? Write down its unit and define it.
36. When does a force do work? Explain.
37. Which form of energy is most preferred and why?
38. Why do we need energy?
39. Why fossil fuels are called non-renewable form of energy?
Long Questions
1. Define K.E. and derive its relation.
2. Define potential energy and derive its relation.
3. How is the energy converted from one form to another? Explain.
4. Derive the relation for work done by a force inclined with the displacement?
5. Define K.E. and derive its relation.
6. Prove that K.E. = 1/2 m v².
7. Define potential energy and derive its relation?
8. List the different forms of energy with examples?
9. How is energy converted from one form to another? Explain.
10. List major sources of energy?
11. Differentiate energy resources as renewable and non-renewable resources of energy with examples of each?
12. Explain the functioning of the solar house heating system?
13. Explain by drawing flow diagram electricity from fossil fuels.
14. List the environmental issues associated with energy. Highlight the solution to these issues?
15. Explain by drawing energy flow diagrams through steady-state system such as filament lamp a power station, a vehicle travelling at a constant speed on a level road?
16. A man has pulled a cart through 35 m applying a force of 300 N. Find the work done by the man.
17. A block weighing 20 N is lifted 6 m vertically upward. Calculate the potential energy stored in it.
18. A car weighing 12 k N has a speed of 20 ms⁻¹. Find its kinetic energy.
"19. A 500 g stone is thrown up with a velocity of 15 ms⁻¹. Find its
(i) P.E. at its maximum height
(ii) K.E. when it hits the ground"
20. On reaching the top of a slope 6 m high from its bottom, a cyclist has a speed of 1.5 ms⁻¹. Find the kinetic energy and the potential energy of the cyclist. The mass of the cyclist and his bicycle is 40 kg.
21. A motor boat moves at a steady speed of 4 ms⁻¹. Water-resistance acting on it is 4000 N. Calculate the power of its engine.
22. A man pulls a block with a force of 300 N through 50 m in 60 s. Find the power used by him to pull the block.
23. A 50 kg man moved 25 steps up in 20 seconds. Find his power, if each step is 16 cm high.
24. Calculate the power of a pump which can lift 200 kg of water through a height of 6 m in 10 seconds.
25. An electric motor of 1hp is used to run water pump. The water pump takes 10 minutes to fill an overhead tank. The tank has a capacity of 800 liters and height of 15 m. Find the actual work done by the electric motor to fill the tank. Also find the efficiency of the system. (Density of water = 1000 kgm⁻³ ) (Mass of 1 liter of water = 1 kg)
26. Define work. Derive its mathematical formula.
27. Define kinetic energy and derive its mathematical formula
28. Define Gravitational Potential Energy and derive its mathematical formula.
29. Explain different Forms of Energy.
30. Explain Renewable Energy Sources.
31. Explain Solar House Heating.
32. What are the future hopes of the world about energy?
33. Explain Mass — Energy Equation.
34. Explain the electricity from fossil fuels with block diagram.
35. Explain the effect of consumption of Energy on Environment.
36. Draw the Flow Diagram Of An Energy Converter.
37. What is Efficiency? Explain the ideal machine and practical systems.
38. What is Power? Write down its unit and define it.