Question

One watt is equal to __________

(a) one kilowatt per second

(b) one kilo joule per second

(c) one joule per second

(d) one joule per minute

The question was asked during an online exam.

This interesting question is from Current Electricity in section Current Electricity of Physics – Class 12

Answer 1

Correct choice is (c) one joule per second

The best explanation: Watt is the SI unit of power. Power = \(\frac { work \, done}{time}\). The SI unit of work done is the same as energy, that is, joule and that of time is seconds. Therefore, one watt is equal to one joule per second.