Energy

Q.

The energy possessed by a body due to its motion is called_____

Q.

A man is pushing a cart down a slope. Suddenly the cart starts moving faster and he wants to slow it down. What should he do?

Q.

Which of the following physical quantities are measured in joules?

1. Force

2. Displacement

3. Work

4. Energy

Q.

When work is done on a body :

1. it gains energy

2. it looses energy

3. its energy remains constant

4. none of these

Q.

Define 1 joule. [1 MARK]

Q. Match the following based on the properties of magnets.

1. Repel
2. Bipolar
3. Attract

Q.

The output energy of a real-life machine is less than input energy because of :

1. moving parts of machine

2. friction at the moving parts

3. both (A) and (B)

4. none of these

Q.

A man is trying to push a wall as shown below:

He gets tired eventually. What is the work done by the man on the wall?

1. Infinite

2. Zero

3. Positive

4. Negative

Q.

The output energy of a good machine is always greater than the input energy.

1. True
2. False

Q.

Give an example in which a body possesses both kinetic energy and potential energy.

Q.

Energy is defined as the ___________ of doing work.

Q.

The kinetic energy of an object is the energy stored in it.

1. True
2. False

Q.

Energy is capable of doing:

1. Work

2. Pushing a wall

3. Digestion

4. None of the above

Q.

Energy is the capacity to do work

1. True
2. False

Q. What is energy?

Q.

Choose one more correct alternatives for work to be performed, energy must be

1. Destroyed

2. Must be transferred from one form to another

3. Concentrated

4. None of the above

Q. An engine can pump 3000 litre of water to a height of 0.045 km in 10 minute calculate work done by machine and its power rating take efficiency 75%.

Q.

Capacity to do work is called _____.

Q.

The energy possessed by virtue of motion is called ______ energy.

Q.

Machines require proper maintenance for :

1. their efficient use

2. preserving them

3. making them look good

4. both (A) and (B)

Q. Calculate the power of a water pump which lifts 800kg of water to a height of 30m in 300 seconds.

Q.

What is mechanical energy?

Q. What are the types of mechanical energy?

Q. A boy is riding a bicycle. From where do you think the boy is getting his energy?

1. Air
2. Sunlight
3. Food
4. Electricity

Q. LEDs are extensively used to replace bulbs because:

1. they consume less electricity.
2. they have a short life.
3. they have more power.
4. all of the above.

Q.

The SI unit of work is same as that of

1. Force

2. Displacement

3. Power

4. Energy

Q.

What do you mean by work-energy relationship?

Q.

A crane ‘P’ lifts a car upto a certain height in $1minute.$ Another crane ‘Q’ lifts the same car upto the same height in $2minutes$.

I. Crane ‘P’ consumes two times more fuel than crane ‘Q’.

II. Crane ‘P’ supplies two times more power than crane ‘Q’.

Based on the above information, identify the correct option.

1. Statement (I) is false while statement (II) is false.

2. Statement (I) is false while statement (II) is true.

3. Both statements (I) and (II) are true.

4. Both statements (I) and (II) are false.