Transmission Of Heat Question 36
Question: Two rectangular blocks A and B of different metals have same length and same area of cross-section. They are kept in such a way that their cross-sectional area touch each other. The temperature at one end of A is 100°C and that of B at the other end is 0°C. If the ratio of their thermal conductivity is 1 : 3, then under steady state, the temperature of the junction in contact will be
[MP PMT 1985]
Options:
A) 25°C
B) 50°C
C) 75°C
D) 100°C
Show Answer
Answer:
Correct Answer: A
Solution:
It is given that $ \frac{K _{1}}{K _{2}}=\frac{1}{3} $
Therefore $ K _{1}=K $ then $ K _{2}=3K $ the temperature of the junction in contact $ \theta =\frac{K _{1}{\theta _{1}}+K _{2}{\theta _{2}}}{K _{1}+K _{2}} $
$ =\frac{1\times 100+3\times 0}{1+3}=\frac{100}{4} $ = 25°C
BETA
