Question

The resistance of a wire of length L and radius r is R. Which one of the following would provide a wire of the same material of resistance `R/2`?

Options

• Using a wire of same radius and twice the length.

• Using a wire of same radius and half length.

• Using a wire of same length and twice the radius.

• Using a wire of same length and half the radius.

Answer 1

Using a wire of same radius and half length.

Explanation:

We know that a wire's resistance is directly correlated with its length. If the radius of the wire is kept fixed and the length of the wire becomes half, then the resistance of the wire will also be halved. (As the question indicates that the resistivity is constant.)