Question

Unit of power is:
$A.$ watt per second
$B.$ joule
$C.$ watt
$D.$ none of these

Answer 1

Hint: Here we will proceed by writing the formula of unit of power because from that we can calculate the unit of power.

Complete Step-by-Step solution:
Power is defined as the rate at which energy is transferred or converted as the rate at which energy is transferred or converted or the rate of doing work.
The power can be calculated by using the formula of $P = \dfrac{W}{T}$ .
Where P = power
W= work
T= Time
The power is a scalar quantity and is basically the amount of energy consumed per unit time which has no direction.
Power is measured in watts:
$
  1W = 1\dfrac{j}{s} \\
   = 1\dfrac{{kg \times {m^2}}}{{{s^2}}} \\
   = 1\dfrac{{n \times m}}{s} \\
 $
$1watt = 1\dfrac{j}{s} = 1kg \times \dfrac{{{m^2}}}{{{s^2}}}$
According to popular standards the S.I. unit of power is none other than Watt which is represented by the symbol W. Jame Watt’s contribution to industry efficiency was commemorated by naming the watt (W) for him.
Therefore, the correct option is C.
Option A is not a unit of power.
Option B is the unit of energy.

Note: Whenever we come up with this type of problem where we asked to find the unit of a quantity. Then we first write the formula of that quantity and then we will simplify the formula. After simplifying we will get the required unit asked for the quantity (here unit of power).