Question

An incandescent light bulb can be regarded as a resistor. If its power output is 100W, calculate the resistance of the light bulb and the current drawn by the light bulb, assuming the voltage of the power source is 110V.

Answer 1

Answer:$121\ \Omega$

$0.909\ A$

Explanation:

Given

Power $P=100\ W$

Voltage applied $V=110\ V$

Resistance of the bulb is given by

$P=\frac{V^2}{R}$

$100=\frac{110^2}{R}$

$R=\frac{12100}{100}$

$R=121\ \Omega$

Current drawn by the Power source is given by

$P=V\cdot I$

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

$I=\frac{100}{110}$

$I=0.909\ A$