9702/Oct Nov/11/2016/Q24

The diagram shows an experiment to produce a stationary wave in an air column. A tuning fork,

placed above the column, vibrates and produces a sound wave. The length of the air column can

be varied by altering the volume of the water in the tube.

The tube is filled and then water is allowed to run out of it. The first two stationary waves occur

when the air column lengths are 0.14 m and 0.42 m.

What is the wavelength of the sound wave?

A 0.14 m 

B 0.28 m 

C 0.42 m 

D 0.56 m

Solution:
Answer: D

From the figure of first two stationary waves occur when the air column lengths are 0.14m and 0.42m, we can conclude that

½ wavelength = 0.42 – 0.14

    wavelength = 2 (0.28)

                        = 0.56 m

Reference: PYQ - Oct/Nov 2016 Paper 11 Q24