A certain bulb with a resistance of 95 ohms and labeled "150 W" is designated for use in a
A)120-V circuit.
B)240-V circuit.
C)either
D)not enough information

Question

Quizplus · Accepted Answer

We can use the formula P=V^2/R to find the voltage required for the bulb to produce 150 W of power.
For 120 V circuit: P= (120^2)/95 = 151 W (more than the labeled 150 W)
For 240 V circuit: P= (240^2)/95 = 604 W (way more than the labeled 150 W)
Since the bulb is labeled "150 W", it is intended to be used at 120 V, so the answer is A) 120-V circuit.

A Certain Bulb with a Resistance of 95 Ohms and Labeled