Transmission Of Heat Question 342
Question: One end of a conducting rod is maintained at temperature $ 50{}^\circ C $ and at the other end, ice is melting at $ 0{}^\circ C $ . The rate of melting of ice is doubled if:
Options:
A) the temperature is made $ 200^\circ C $ and the area of cross-section of the rod is doubled
B) the temperature is made $ 100{}^\circ C $ and length of rod is made four times long
C) area of cross-section of rod is halved and length is doubled
D) the temperature is made $ 100{}^\circ C $ and the area of cross-section of rod and length both are doubled
Show Answer
Answer:
Correct Answer: D
Solution:
Rate of melting of ice $ \propto $ rate of heat transfer and rate of heat transfer $ =\frac{\text{Temperature difference}}{\frac{l}{KA}} $ or rate of heat transfer $ \propto \frac{\text{(Temperature difference)}}{l}A $ . If temperature difference, A and l, all are doubled, then obviously rate of heat transfer or rate of melting of ice will be quadrupled.
BETA
