Transmission Of Heat Question 243

Question: If the initial temperatures of metallic sphere and disc, of the same mass, radius and nature are equal, then the ratio of their rate of cooling in same environment will be

[J & K CET 2004]

Options:

A) 1 : 4

B) 4 : 1

C) 1 : 2

D) 2 : 1

Show Answer

Answer:

Correct Answer: D

Solution:

$ E\propto AT^{4} $

Therefore $ \frac{{E _{\text{sphere}}}}{{E _{\text{Disc}}}}=\frac{4\pi r^{2}}{2\pi r^{2}}\times {{( \frac{T}{T} )}^{4}}=\frac{2}{1} $