Question

Derive an equation for electric power

Answer 1

SoluTion:

Power = Rate of consumption of energy.

$\implies$ P = $\sf{\dfrac{E}{t}}$

Where, E is energy and t is time.

Energy can be changed into useful work, so we can write above expression as :

$\implies$ P = $\sf{\dfrac{W}{t}}$

We know that, W = V.Q [ where V is potential difference and Q is charge ]

$\implies$ P = $\sf{\dfrac{V.Q}{t}}$

Also, $\sf{\dfrac{Q}{t}}$ = I [ current ]

$\implies$ $\large{\boxed{\red{\sf{P\:=\:V.I}}}}$

$\rule{200}2$

• Power is rate of doing work.
• Power can also be said as rate of consumption of energy.
• It's S.I unit is watt.