Transmission Of Heat Question 96
Question: Two rods (one semi-circular and other straight) of same material and of same cross-sectional area are joined as shown in the figure. The points A and B are maintained at different temperature. The ratio of the heat transferred through a cross-section of a semi-circular rod to the heat transferred through a cross section of the straight rod in a given time is
[UPSEAT 2002]
Options:
A) 2 : p
B) 1 : 2
C) p : 2
D) 3 : 2
Show Answer
Answer:
Correct Answer: A
Solution:
$ \frac{dQ}{dt}=\frac{KA\Delta \theta }{l} $ , For both rods K, A and Dq are same
Therefore $ \frac{dQ}{dt}\propto \frac{1}{l} $ So $ \frac{{{(dQ/dt)} _{semi,circular}}}{{{(dQ/dt)} _{straight}}}=\frac{l _{straight}}{l _{semicircular}}=\frac{2r}{\pi ,r}=\frac{2}{\pi } $ .
BETA
