doppler effect questions with solutions

Showing 1–10 of 32 questions

• MCQmediumWave Motiondoppler effect

  A stationary source and a stationary reflecting wall lie on opposite sides of an observer. The source emits frequency f. The observer moves towards the wall with speed u, so the direct wave reaches the observer from behind while the reflected wave reaches from ahead. What is the beat frequency heard by the observer?

  Options

  • Option A

    fu/v

  • Option B

    2f×u/v

  • Option C

    f×v/(v-u)

  • Option D

    2f×v/(v+u)

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →
• A/RmediumWave Motiondoppler effect

  Choose the correct option for the following Assertion (A) and Reason (R).

  Assertion

  A moving observer can hear a Doppler-shifted frequency even though the wavelength of the sound in the stationary medium remains unchanged.

  Reason

  Observer motion changes the rate at which the observer encounters successive wavefronts, not the spacing between wavefronts in the medium.

  Options

  • Option A

    Both A and R are true and R is the correct explanation of A.

  • Option B

    Both A and R are true but R is NOT the correct explanation of A.

  • Option C

    A is true but R is false.

  • Option D

    A is false but R is true.

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →
• Multi-correctmediumWave Motiondoppler effect

  For the classical Doppler effect of sound in a stationary medium, which statements are correct?

  Select all that apply

  • Option A

    Source motion changes the wavelength established in the medium.

  • Option B

    Observer motion does not alter the wavelength already present in the medium.

  • Option C

    Only velocity components along the instantaneous source-observer line enter the usual radial Doppler shift.

  • Option D

    For a source and observer approaching each other, f' = f×(v+uₒ)/(v-uₛ).

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →
• Multi-correctmediumWave Motiondoppler effect

  Which statements are correct for non-collinear or circular Doppler-motion situations in the classical approximation?

  Select all that apply

  • Option A

    At an instant, only radial velocity contributes to the usual first-order Doppler shift.

  • Option B

    A source moving exactly transverse to the source-observer line has zero instantaneous radial Doppler shift.

  • Option C

    A source moving in a circle centred on a stationary observer produces no classical Doppler shift at that observer.

  • Option D

    For a far-away observer viewing a circularly moving source, maximum and minimum frequencies occur near maximum approach and recession radial speeds.

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →
• NumericmediumWave Motiondoppler effect

  A stationary observer hears a moving source at 360 Hz while it approaches and at 300 Hz after it has passed and is receding. The speed of sound is 330 m/s. If the source speed is N m/s, find N.

  Your answer

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →
• MCQmediumWave Motiondoppler effect

  A siren of frequency 240 Hz is mounted on a vehicle moving at 60 m/s along a straight road. A stationary observer lies on the road ahead. The speed of sound is 300 m/s. What is the sudden drop in observed frequency as the vehicle passes the observer and changes from approaching to receding?

  Options

  • Option A

    60 Hz

  • Option B

    80 Hz

  • Option C

    100 Hz

  • Option D

    120 Hz

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →
• MCQmediumWave Motiondoppler effect

  A sound source moves with constant speed on a circle whose centre is occupied by a stationary observer. The source emits a constant frequency f. Neglect wind and relativistic effects. What frequency is heard by the observer?

  Options

  • Option A

    Always greater than f

  • Option B

    Always less than f

  • Option C

    Alternately greater and smaller than f

  • Option D

    Exactly f throughout the motion

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →
• NumericdifficultWave Motiondoppler effect

  An audio transmitter T and receiver R are suspended from identical 8 m strings. They are displaced in opposite horizontal directions by θ₀ = cos⁻¹(0.9) and released together. The transmitter frequency is 660 Hz and sound speed is 330 m s⁻¹. With g = 10 m s⁻², find the maximum variation in received frequency in hertz.

  

  Your answer

  Check answerShow answer

  JEE Advanced 2025 Paper 2

  Open question & full solution →
• NumericmediumWave Motiondoppler effect

  A person driving car at a constant speed of 15 m/s is approaching a vertical wall. The person notices a change of 40 Hz in the frequency of his car's horn upon reflection from the wall. The frequency of horn is ______ Hz.

  Your answer

  Check answerShow answer

  JEE Mains6 April 2023Shift 1Morning Shift

  Open question & full solution →
• MCQmediumWave Motiondoppler effect

  A stationary source emits frequency f towards a large reflecting wall moving directly towards the source with speed u. The reflected sound returns to the stationary source. Which expression gives the frequency received back at the source?

  Options

  • Option A

    f×(v+u)/(v-u)

  • Option B

    f×(v-u)/(v+u)

  • Option C

    f×v/(v-u)

  • Option D

    f×(v+u)/v

  Check answerShow answer

  JEE MainsNEETJEE Advanced

  Open question & full solution →