Transmission Of Heat Question 52
Question: If the radius and length of a copper rod are both doubled, the rate of flow of heat along the rod increases
Options:
A) 4 times
B) 2 times
C) 8 times
D) 16 times
Show Answer
Answer:
Correct Answer: B
Solution:
$ Q\propto \frac{A}{l}\propto \frac{r^{2}}{l} $
Therefore $ \frac{Q _{2}}{Q _{1}}=\frac{r _{2}^{2}}{r _{1}^{2}}\times \frac{l _{1}}{l _{2}} $
Therefore $ \frac{Q _{2}}{Q _{1}}=\frac{4}{1}\times \frac{1}{2} $
Therefore $ Q _{2}=2Q _{1} $
BETA
