RRB Technician 2014 Ques 17
Question: A sound wave of wavelength 90 cm in glass is refracted into air. If the velocity of sound in glass is 5400 m/s, the wavelength of the wave in air is
Options:
A) 55 cm
B) 5.5cm
C) 55m
D) 5.5m
Show Answer
Answer:
Correct Answer: B
Solution:
- Velocity = Frequency x Wavelength In glass, $ 5400\times 100=n\times 90 $
$ \Rightarrow $ $ n=\frac{5400\times 100}{90}cps $ in air $ \frac{330\times 100}{\lambda }=n=\frac{5400\times 100}{90} $
$ \therefore $ $ \lambda =\frac{330\times 100\times 90}{5400\times 100}=5.5cm $
BETA
