Transmission Of Heat Question 299
Question: A black body radiates energy at the rate of $ 1\times 10^{5}J/s\times m^{2} $ at temperature of $ 227{}^\circ C $ . The temperature to which it must be heated so that it radiates energy at rate of $ 1\times 10^{9}J\text{/}sm^{2} $ , is
Options:
A) 5000 K
B) 5000$ {}^\circ C $
C) 500 K
D) 500$ {}^\circ C $
Show Answer
Answer:
Correct Answer: A
Solution:
$ \frac{E _{2}}{E _{1}}={{( \frac{T _{2}}{T _{1}} )}^{4}} $
$ \Rightarrow $ $ \frac{T _{2}}{T _{1}}={{( \frac{E _{2}}{E _{1}} )}^{1/4}}={{( \frac{10^{9}}{10^{5}} )}^{1/4}}=10 $
$ \Rightarrow $ $ T _{2}=10T _{1}=10\times (273+227)=5000,K $
BETA
