A certain sample carries a current of 4 A when the potential difference is 2 V and a current of 10 A when the potential difference is 4 V.This sample:
A)obeys Ohm's law
B)has a resistance of 0.5 $\Omega$ at 2 V
C)has a resistance of 2 $\Omega$ at 2 V
D)has a resistance of 25 $\Omega$ at 2 V
E)does not have a resistance

Question

Quizplus · Accepted Answer

According to Ohm's law, resistance is equal to the potential difference divided by the current (R=V/I). Using the given measurements, we can calculate the resistance at 2 V:
R = V/I = 2/4 = 0.5 Ω
Since the resistance is constant for different potential differences, we can assume that this sample follows Ohm's law. Therefore, the best choice is B, with a resistance of 0.5 Ω at 2 V.

A Certain Sample Carries a Current of 4 a When Ω\OmegaΩ

A Certain Sample Carries a Current of 4 a When $\Omega$