1)

Three very large plates of the same area are kept parallel and close to each other. They are considered ideal black surfaces and have very high thermal conductivity. The first and third plates are maintained at temperatures 2T and 3T respectively. The temperature of the middle (i.e., second) plate under steady-state conditions is


A) (652)14T

B) (974)14T

C) (972)14T

D) (97)14T

Answer:

Option C

Explanation:

Let temperature of middle plate in steady state is T0

611202162_n1.PNG

 Q1=Q2

 Q= net rate of heat flow

   σA(3T)4σAT40=σAT40σA(2T)4

 Solving this equation , we get

 T0=(972)14T