Work and Power: Force That Gets Things Done

Section A: Work Done

Question 1mcq

In science, work is done when force causes what?

A.No movement

B.Displacement in direction of force

C.Only heating

D.Only mass change

Question 2mcq

A person pushes a wall hard, but wall does not move. Work done on wall is?

A.Zero

B.Large

C.Negative always

D.Equal to body weight

Question 3mcq

A force of

10\,N

moves an object

3\,m

. Work done is?

A.

13\,J

B.

10\,J

C.

3.3\,J

D.

30\,J

Question 4mcq

If

50\,J

work moves an object

5\,m

, force is?

A.

55\,N

B.

250\,N

C.

10\,N

D.

45\,N

Question 5mcq

When is work done negative?

A.Both zero

B.In opposite directions

C.Same direction

D.Perpendicular always positive

Question 6mcq

What is the SI unit of work?

A.joule

B.pascal

C.watt

D.newton

Section B: Power

Question 7mcq

Power is defined as the rate of what?

A.Making force zero

B.Changing mass

C.Producing sound only

D.Doing work

Question 8mcq

What is the SI unit of power?

A.joule

B.hertz

C.watt

D.newton

Question 9mcq

If

100\,J

work is done in

5\,s

, power is?

A.

500\,W

B.

20\,W

C.

105\,W

D.

5\,W

Question 10mcq

A motor does

600\,J

work in

30\,s

. Power is?

A.

20\,W

B.

18000\,W

C.

30\,W

D.

630\,W

Question 11mcq

Which option correctly completes this statement: Two machines do same work. The one taking less time has?

A.Less power

B.No energy

C.Zero power

D.Greater power

Question 12mcq

One watt is equal to which unit expression?

A.

1\,kg/s

B.

1\,N/m

C.

1\,J/s

D.

1\,m/J