Transmission Of Heat Question 121
Question: Four identical rods of same material are joined end to end to form a square. If the temperature difference between the ends of a diagonal is $ 100^{o}C $ , then the temperature difference between the ends of other diagonal will be
[MP PET 1989; RPMT 2002]
Options:
A) $ 0^{o}C $
B) $ \frac{100}{l}{{\ }^{o}}C $ ; where l is the length of each rod
C) $ \frac{100}{2l}{{\ }^{o}}C $
D) $ 100^{o}C $
Show Answer
Answer:
Correct Answer: A
Solution:
Suppose temperature difference between A and B is 100°C and qA > qB Heat current will flow from A to B via path ACB and ADB. Since all the rod are identical so (Dq)AC =(Dq)AD (Because heat current $ H=\frac{\Delta \theta }{R}; $ here R = same for all.)
Therefore $ {\theta _{A}}-{\theta _{C}}={\theta _{A}}-{\theta _{D}} $
Therefore $ {\theta _{C}}={\theta _{D}} $ i.e. temperature difference between C and D will be zero.
BETA
