wave_mechanics basics_of_mechanical_waves Question 10

Question: The wavelength of ultrasonic waves in air is of the order of

[EAMCET 1989]

Options:

A) $ 5\times {{10}^{-5}}cm $

B) $ 5\times {{10}^{-8}}cm $

C) $ 5\times 10^{5}cm $

D) $ 5\times 10^{8}cm $

Show Answer

Answer:

Correct Answer: A

Solution:

$ \lambda =\frac{v}{n};n\approx 50,000Hz $ , $ v=330 $ m/sec

Therefore $ \lambda =\frac{330}{50000}m $

$ =6.6\times {{10}^{-5}}cm\approx 5\times {{10}^{-5}}cm $