Question

If an increase in the length of copper wire is 0.5% due to stretching, the percentage increase in its resistance is:

• A. 1%
• B. 0.2%
• C. 1%
• D. 2%

Answer 1

The correct option is A

1%

As R = ρ$\frac{L}{A}$
Therefore, for small increase in length 'x' in percentage, percentage increase in resistance is 2x.