Question

The coefficient of thermal conductivity of a metal rod depends on its

• A. area of cross section
• B. mass
• C. material of the rod
• D. length used

Hint:

Thermal conductivity is a property of the material only.

Answer 1

The Correct Option is C

Step 1: Idea:
Ask which choice is an intrinsic property.

Step 2: Result:
Area, mass and length describe the size of a rod, and doubling any of them does not change what the rod is made of. $K$ stays the same for a thick or thin copper wire. Only the material matters.

Final Answer:
Thermal conductivity depends on the material of the rod, option (C). \[ \boxed{\text{Material of the rod}} \]