Question

If length of a wire is doubled and its cross-section is also doubled, then the resistance will

• A. increase 8 times
• B. decrease 4 times
• C. become 4 times
• D. remain unchanged

Answer 1

The correct option is D remain unchanged

Since the increase in length cancels out the increase in cross sectional area, The resistance remains unchanged.
$Resistance=\frac{\rho L}{A}$
Here $\rho$ is the resistivity of the wire.