A source of sound is emitting a waves of wavelength 40 cm in air. If this source starts moving towards east with a velocity one-fourth the velocity of sound then the apparent wavelength of sound in a direction opposite to that of source will be

20 cm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

50 cm

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

80 cm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

100 cm

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B 50 cm
$λ^{'} = \frac{(v + v_{s}) λ}{v}$ , here $λ = 40 cm$ ,

$v_{s} = (\frac{1}{10}) v$ , substituting these values in the equation,
$λ^{'} = (1 + \frac{1}{10}) 40 = 50 cm$

Suggest Corrections

Similar questions

Q. A source of sound produces waves of wavelength 20 cm in air. It is moving with a velocity one-fourth the velocity of sound towards east. The apparent wavelength noted by a man moving in the same direction with velocity equal to 2/3rd of velocity of sound wave and at the back of source is :

Q. A source of sound produces waves of

λ = 60

cm in air. It is moving with a velocity one-sixth the velocity of sound towards a stationary observer. The apparent wavelength noted by the observer is?

Q. A source of sound produces waves of wave length 48 cm. This source is moving towards north with speed 1/4 th that of sound. The apparent wavelength of the waves to an observer standing south of the moving source will be

The wavelength is 120 cm when the source is stationary. If the source is moving with relative velocity of 60 m/sec towards the observer, then the wavelength of the sound wave reaching to the observer will be (velocity of sound = 330 m/s)

Q. A source of sound emits waves of frequency

f_{0} = 1200 Hz .

The source is travelling with a velocity

v_{1} = 30 m/s .

towards east. There is a large reflecting surface in front of the source which is travelling with a velocity

v_{2} = 60 m/s

towards west. Speed of sound in air is

v = 330 m/s

. Find the ratio of wavelength

(λ_{1})

of sound emitted by source when travelling towards the reflecting surface to the wavelength

(λ_{2})

of sound approaching the source after getting reflected.

Join BYJU'S Learning Program

A source of sound is emitting a waves of wavelength 40 cm in air. If this source starts moving towards east with a velocity one-fourth the velocity of sound then the apparent wavelength of sound in a direction opposite to that of source will be

The correct option is B 50 cmλ′=(v+vs)λv, here λ=40 cm, vs=(110)v, substituting these values in the equation,λ′=(1+110)40=50 cm

The correct option is B 50 cm
$λ^{'} = \frac{(v + v_{s}) λ}{v}$ , here $λ = 40 cm$ ,

$v_{s} = (\frac{1}{10}) v$ , substituting these values in the equation,
$λ^{'} = (1 + \frac{1}{10}) 40 = 50 cm$