Question

A copper bar MN of length 50 cm has a water layer of thickness 0.5 mm at end m as shown in Fig. The temperatures maintained at ends are as shown in Fig. θ is nearly.

Given: 

Thermal conductivity of copper = 45 x 10^-2 Wm^-1 (K)^-1 

Thermal conductivity of water = 60 x 10^-4 Wm^-1 (K)^-1)

(1) 98°C

(2) 96°C

(3) 93°C

(4) 90°C

Answer 1

(3) 93°C

The rate of flow of heat in water layer at end M and copper bar MN is same. Therefore