Question

Which is a derived unit?

a.) kilogram
b.) joule
c.) micrometer
d.) millimeter

Answer 1

Joule us a derived unit

Answer 2

Answer : The correct option is, (b) joule

Explanation :

Derived unit : Derived units are derived from some basic units.

From the given options, option a, c and d are the basics units. While the option b is the derived unit.

The derived unit Joule is the unit of work which is derived as,

`work=force* displacement`

The unit of force is newton (N) and 1 N is equal to the
`1\text{ Kg }m/s^2`

The unit of displacement is meter (m).

Now by putting these units in above formula, we get the unit of work.

`work=(1\text{ Kg }m/s^2)* (m)=1\text{ Kg }m^2/s^2=Joule`

Hence, the derived unit is, joule.