Question

The ratio of the thermal conductivity of two rods of different materials is 6:5. The two rods of same area of cross section and same thermal resistance will have the length in the ratio

• A. \(5:6\)
• B. \(6:5\)
• C. \(1:3\)
• D. \(3:1\)

Hint:

Thermal resistance R = L / (kA).

Answer 1

The Correct Option is B

Step 1: Formula
$R = L/(kA)$.

Step 2: Equate
Same $R$ and $A$ imply $L \propto k$.

Step 3: Answer
$6:5$, option (B).

Final Answer:
Option (B). \[ \boxed{6:5} \]