NTA Abhyas JEE Main2020PhysicsThermal Properties of MatterPractice
Two rectangular blocks A and B of different metals have the same length and the same area of cross-section. They are kept with their lengths aligned and their cross-sections in contact. The temperature at one end of A is 100 ° C and that of at the other end B is 0 ° C . If the ratio of their thermal conductivity is 1 : 3 , then under steady-state, what will be the temperature (in ° C ) of the junction?
Correct answer
25
Step-by-step solution
it is given that K 1 K 2 = 1 3 ⇒ K 1 = K then K 2 = 3 K The temperature of the junction in contact θ = K 1 θ 1 + K 2 θ 2 K 1 + K 2 = 1 × 100 + 3 × 0 1 + 3 = 100 4 = 25   ° C