wave_mechanics basics_of_mechanical_waves Question 19

Question: In a medium sound travels 2 km in 3 sec and in air, it travels 3 km in 10 sec. The ratio of the wavelengths of sound in the two media is

[NTSE 1995]

Options:

A) 1 : 8

B) 1 : 18

C) 8 : 1

D) 20 : 9

Show Answer

Answer:

Correct Answer: D

Solution:

$ v\propto \lambda $

Therefore $ \frac{{\lambda _{1}}}{{\lambda _{2}}}=\frac{v _{1}}{v _{2}}=\frac{2/3}{3/10}=\frac{20}{9} $