Transmission Of Heat Question 231
Question: If the temperature of a hot body is increased by 50% then the increase in the quantity of emitted heat radiation will be
[RPET 1998; EAMCET 2001; MP PMT 2003]
Options:
A) 125%
B) 200%
C) 300%
D) 400%
Show Answer
Answer:
Correct Answer: D
Solution:
$ Q\propto T^{4} $
Therefore $ \frac{Q _{1}}{Q _{2}}={{( \frac{T _{1}}{T _{2}} )}^{4}} $
Therefore $ \frac{Q _{1}}{Q _{2}}={{( \frac{T}{T+T/2} )}^{4}}=\frac{16}{81} $
Therefore $ Q _{2}=\frac{81}{16}Q _{1} $ % increase in energy $ =\frac{Q _{2}-Q _{1}}{Q _{1}}\times 100=400% $
BETA
