Transmission Of Heat Question 315
Question: The radiant energy from the sun incident normally at the surface of earth is $ 20\ kcal/m^{2}min $ What would have been the radiant energy incident normally on the earth, if the sun had a temperature twice of the present one
Options:
A) $ 160\ kcal/m^{2}\ min $
B) $ 40\ kcal/m^{2}\ min $
C) $ 320\ kcal/m^{2}\ min $
D) $ 80\ kcal/m^{2}\ min $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{E _{2}}{E _{1}}={{( \frac{T _{2}}{T _{1}} )}^{4}} $
$ \Rightarrow $ $ \frac{E _{2}}{20}={{( \frac{2T}{T} )}^{4}} $ =16
$ \Rightarrow $ $ E _{2}=320\ kcal/m^{2} $ min.
BETA
