Two 100 W bulbs differ in that one is designed for the American 120 V rms and the other is designed for the European 220 V rms.Which bulb has the greater resistance,and what is that resistance?
A) American,288 $\Omega$
B) American,144 $\Omega$
C) European,484 $\Omega$
D) European,242 $\Omega$
E) they are the same,265 $\Omega$

Question

Quizplus · Accepted Answer

The resistance of a bulb can be calculated using the formula $ R = \frac{V^2}{P} $. For the European bulb: $ R = \frac{220^2}{100} = 484 \, \varOmega $. For the American bulb: $ R = \frac{120^2}{100} = 144 \, \varOmega $. The European bulb has the greater resistance.

Two 100 W Bulbs Differ in That One Is Designed Ω\OmegaΩ

Two 100 W Bulbs Differ in That One Is Designed $\Omega$