Which of the following are appropriate units for power?

Question: Which of the following are appropriate units for power?

A) newton·meter

B) watt

C) H.P./sec

D) joule/sec

Watt  and Joule/sec are the appropriate units for power.

Explanation:

As per the question, the physical quantity given is power.

The power is defined as the rate of consumption of energy or the rate of doing work.

Let us consider W is the amount of work done by a body in time t .

Mathematically the power of that body is written as -

                                power

The unit of work is joule and the unit of time is second.

Hence, the unit of power is joule/sec.

we know that one joule/sec. = one watt.

Hence, watt is also another unit of power. Newton-metre can not be a unit of power . It may be considered as a unit of work.

Similarly H.P/sec is also not a unit of power. Here H.P stands for horse power which is another unit of power . Hence, joule/sec. and watt are the appropriate units of power.