Transmission Of Heat Question 239
Question: Star A has radius r surface temperature T while star B has radius 4r and surface temperature T/2. The ratio of the power of two starts, PA : PB is
[MP PMT 2004]
Options:
A) 16 : 1
B) 1 : 16
C) 1 : 1
D) 1 : 4
Show Answer
Answer:
Correct Answer: C
Solution:
Power $ P\propto AT^{4}\propto r^{2}T^{4} $
Therefore $ \frac{P _{2}}{P _{1}}={{( \frac{r _{2}}{r _{1}} )}^{2}}\times {{( \frac{T _{2}}{T _{1}} )}^{4}} $
$ ={{( \frac{4r}{r} )}^{2}}\times {{( \frac{T/2}{T} )}^{4}} $ =1.
BETA
