A 150 W light bulb is designed for an ac voltage of 120 V rms. What is the resistance of the bulb?
A) 150 Ω
B) 144 Ω
C) 96 Ω
D) 68 Ω
E) 48 Ω

Name: A 150 W light bulb is designed for an ac voltage of 120 V rms. What is the resistance of the bulb? A) 150 Ω B) 144 Ω C) 96 Ω D) 68 Ω E) 48 Ω
Brand: Quizplus
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Question

Quizplus · Accepted Answer

Power, P = 150 W
Voltage, V = 120 V rms
Let the resistance be R.
Using Ohm's Law and the definition of rms voltage and current,
P = V^2/R
R = V^2/P = (120 V)^2 / 150 W = 96 Ω.

A 150 W Light Bulb Is Designed for an Ac