Wave Mechanics Question 833
Question: The temperature at which the speed of sound in air becomes double of its value at $ 27^{o}C $ is
[CPMT 1997; UPSEAT 2000; DPMT 2003]
Options:
A) $ 54^{o}C $
B) $ 327^{o}C $
C) $ 927^{o}C $
D) $ -123^{o}C $
Show Answer
Answer:
Correct Answer: C
Solution:
$ v=\sqrt{\frac{\gamma RT}{M}} $
Therefore $ v\propto \sqrt{T} $ i.e. if v is doubled then T becomes four times, hence $ T _{2}=4T _{1}=4(273+27)=1200K=927{}^\circ C $