A copper wire is stretched to become 10% longer. Its resistance
A) stays the same.
B) becomes 1.2 times larger.
C) becomes 1.1 times larger.
D) becomes 1.1 times smaller.
E) becomes 1.2 times smaller.

Question

Quizplus · Accepted Answer

When a copper wire is stretched to become 10% longer, its length increases by 10%, and its cross-sectional area decreases, leading to an increase in resistance. The resistance of a wire is directly proportional to its length (L) and inversely proportional to its cross-sectional area (A). Since both L increases and A decreases, the overall effect is an increase in resistance. The exact calculation involves the square of the length change (1.1^2 = 1.21) due to the area's inverse relationship, making the resistance approximately 1.2 times larger.

A Copper Wire Is Stretched to Become 10% Longer