Question

A certain piece of silver of given mass is to be made like a wire. Which of the following combination of length (L) and the area of cross-sectional (A) will lead to the smallest resistance

• A. L and A
• B. 2L and A/2
• C. L/2 and 2A
• D. Any of the above, because volume of silver remains same

Answer 1

The correct option is C L/2 and 2A

We know,
$R=\frac{\rho \times L}{A}⟹R\propto \frac{L}{A}$ ( As $\rho$ is same for all the cases)

Clearly, value of $\frac{L}{A}$ is minimum for C.