Work And Energy

31.

The work done by friction is

A.	positive	B.	negative
C.	zero	D.	none of these

32.

The area under the force displacement graph represents

A.	area	B.	work done
C.	power	D.	none of these

33.

The dimension of power is

A.	[ML2T-3]	B.	[ML2T-2]
C.	[ML2T3]	D.	none of these

34.

Propulsion force of a rocket is

A.	non-conservative force	B.	conservative force
C.	both (a) and (b)	D.	non of these

35.

The dot product of force and velocity is

A.	power	B.	work
C.	impulse	D.	torque

36.

Geothermal energy is a ____________________ source of energy.

A.	non-renewable	B.	stable
C.	renewable	D.	none of the above

37.

The source of tidal energy is

A.	sun	B.	earth
C.	both (a) and (b)	D.	moon

38.

________________ cells converts solar energy into electrical energy

A.	rotory	B.	photovoltaic
C.	galvanic	D.	non of these

39.

On a clear day at noon the solar energy reaching the earth is

A.	1.44kw/m2	B.	1.4kw/m2
C.	1 kw/m2	D.	none

40.

Biomass can be converted into fuels by

A.	direct combustion	B.	fermentation
C.	both (a) and (b)	D.	none of these

Some Thing Urdu