Question

An electric lamp uses energy at the rate of 48 W on a 12 V supply.
How much charge passes through the lamp in 2.0 seconds ?

Answer 1

Given that,

Power of an electric lamp, $P=48W$

Voltage, $V=12V$

Time, $t=2s$

Power is the product of voltage and the current flowing.

$I=\frac{P}{V}$

$I=\frac{48W}{12V}$

$I=4A$

Also, the electric current is the ratio of electric charge and time

$I=\frac{q}{t}$

$q=I\times t$

$q=4A\times 2s$

$q=8C$

The charge that is passing through the lamp is $8$ Coulombs.