JEE Main202313 Apr 2023Evening ShiftPhysicsThermal Properties of MatterActual
Two plates A and B have thermal conductivities 84 W m - 1 K - 1 and 126 W m - 1 K - 1 respectively. They have same surface area and same thickness. They are placed in contact along their surfaces. If the temperatures of the outer surfaces of A and B are kept at 100 ∘ C and 0 ∘ C respectively, then the temperature of the surface of contact in steady state is_____ C ∘ .
Correct answer
0
Step-by-step solution
Let the temperature of the contact surface be T , So, H A = H B K A A ' ( T A - T ) L = K B A ' ( T - T B ) L ⇒ 84 ( 100 - T ) = 126 ( T - 0 ) ⇒ 2 ( 100 - T ) = 3 T ⇒ T = 40   ° C