Transmission Of Heat Question 49
Question: Two rods of same length and material transfer a given amount of heat in 12 seconds, when they are joined end to end. But when they are joined lengthwise, then they will transfer same heat in same conditions in
[BHU 1998; UPSEAT 2002]
Options:
A) 24 s
B) 3 s
C) 1.5 s
D) 48s
Show Answer
Answer:
Correct Answer: D
Solution:
Let the heat transferred be Q. When rods are joined end to end. Heat transferred by each rod$ =Q=\frac{KA\Delta \theta }{l}\times 12 $ ?..(i) When rods are joined lengthwise, $ Q=\frac{KA\Delta \theta }{2l}t $ ?..(ii) From equation (i) and (ii) we get $ t=48\ s $
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