Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
BITSAT2023PhysicsWaves and SoundActual

The engine of a train moving with speed 10 ~ms ⁻¹ towards a platform sounds a whistle at frequency 400 ~Hz . The frequency heard by a passenger inside the train is (neglect air speed. Speed of sound in air 330 ~ms ⁻¹ )

Options

  1. A200 ~Hz
  2. B400 ~Hz
  3. C412 ~Hz
  4. D388 ~Hz

Correct answer

B. 400 ~Hz

Step-by-step solution

The relative velocity of a passenger with respect to source of sound (engine of train) is 0 . So there will be no Doppler's effect. So frequency heard is 400 ~Hz .

Practice Waves and Sound on Quantrex Academy →

More from Waves and Sound

The speed of sound in oxygen at S.T.P. will be approximately: (Given, . R =8.3 JK ⁻¹, =1.4 ) 2024A plane progressive wave is given by y=2 2 (330 t-x) m . The frequency of the wave is: 2024The ratio of speed of sound in hydrogen gas to the speed of sound in oxygen gas at the same temperature is: 2023A submarine A travelling at 17 ~m / s is being chased along the line of its velocity by another submarine B travelling at 34 ~m / s . B sends a sonar signal of 600 ~Hz to detect A 2022Transverse waves of the same frequency are generated in two steel wires A and B . The diameter of A is twice that of B and the tension in A is half that in B . The ratio of the vel 2022A direct current of 6 ~A is superimposed on an alternating current I=10 t flowing through a wire. The effective value of the resulting current will be 2022The frequency of whistle of an engine appears to be (4 / 5)^ th of initial frequency when it crosses a stationary observer. If the velocity of sound is 330 ~m / s , then the speed 2021The displacement y of a particle in a medium can be expressed as, y=10⁻⁶ (100 t+20 x+ 4 ) m where t is in second and x in meter. The speed of the wave is 2021 Full Waves and Sound list All BITSAT PYQs