Question

The outer ends of two bars A and B are at 100°C and 50° respectively. Calculate the temperature at the welded joint if they have the same cross-section and the same length and their thermal conductivities are in the ratio of A:B = 7:5.

(a) 79.166°C

(b) 80.548°C

(c) 20.157°C

(d) 58.147°C

This question was posed to me in an online interview.

Asked question is from Thermal Conductivity topic in portion Thermal Properties of Matter of Engineering Physics I

Answer 1

Right option is (a) 79.166°C

To explain I would say: K1/K2 = (θ2-θ3)/(θ1-θ2)

θ2= 79.166℃