Question

Rods \( A \) and \( B \) have their lengths in the ratio \( 1 : 2 \). Their thermal conductivities are \( K_1 \) and \( K_2 \) respectively. The temperatures at the ends of each rod are \( T_1 \) and \( T_2 \). If the rate of flow of heat through the rods is equal, the ratio of area of cross section of \( A \) to that of \( B \) is

• A. \( \frac{2K_2}{K_1} \)
• B. \( \frac{K_2}{4K_1} \)
• C. \( \frac{K_2}{K_1} \)
• D. \( \frac{K_2}{2K_1} \)

Hint:

For equal heat flow through rods, use \( \frac{KA}{L} \) comparison when temperature difference is same.

Answer 1

The Correct Option is D