Transmission Of Heat Question 123
Question: One end of a copper rod of length $ 1.0\ m $ and area of cross-section $ {{10}^{-3}} $ is immersed in boiling water and the other end in ice. If the coefficient of thermal conductivity of copper is $ 92\ cal/m\text{-}s{{\text{-}}^{o}}C $ and the latent heat of ice is $ 8\times 10^{4}cal/kg $ , then the amount of ice which will melt in one minute is
[MNR 1994]
Options:
A) $ 9.2\times {{10}^{-3}}kg $
B) $ 8\times {{10}^{-3}}kg $
C) $ 6.9\times {{10}^{-3}}kg $
D) $ 5.4\times {{10}^{-3}}kg $
Show Answer
Answer:
Correct Answer: C
Solution:
Heat transferred in one minute is utilised in melting the ice so, $ \frac{KA({\theta _{1}}-{\theta _{2}})t}{l}=m\times L $
$ \Rightarrow m=\frac{{{10}^{-3}}\times 92\times (100-0)\times 60}{1\times 8\times 10^{4}}=6.9\times {{10}^{-3}}kg $
BETA
