Consider the resistance of two wires made of the same material. Wire A has a length that is twice the length of wire B; the cross-sectional area of wire A is twice the cross-sectional area of wire B. The resistance of wire A is
A) the same as wire B.
B) twice the value of wire B.
C) half the value of wire B.
D) one-quarter the value of wire B.

Question

Quizplus · Accepted Answer

The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. Since wire A has twice the length (increasing resistance) and twice the cross-sectional area (decreasing resistance) compared to wire B, these changes cancel each other out, making the resistance of wire A the same as wire B.

Consider the Resistance of Two Wires Made of the Same