Doppler's Effect - MCQ - Basic

Doppler's Effect - MCQ - Basic Level

Dear Readers,

Physics is an important subject in preparation for various Competitive exams. To keep a track of your preparation we have designed a small quiz of Basic Level Questions on Doppler's Effect. You have 10 minutes to solve the quiz, click the start timer button in order to start the timer and then click on submit button at the end to submit the quiz and view your scores and correct answers.

Q1. Doppler effect is independent of

•  Distance between source and listener
•  Velocity of source
•  Velocity of listener
•  None of these

Q2. A source and an observer approach each other with same velocity 50 m/s. If the apparent frequency is 435 s–1, then the real frequency is

•  320 sec^-1
•  360 sec^-1
•  390 sec^-1
•  420 sec^-1

Q3. A source emits a sound of frequency of 400 Hz, but the listener hears it to be 390 Hz. Then

•  The listener is moving towards the source
•  The source is moving towards the listener
•  The listener is moving away from the source
•  The listener has a defective ear

Q4. A source and an observer are moving towards each other with a speed equal to v/2 where v is the speed of sound. The source is emitting sound of frequency n. The frequency heard by the observer will be

•  Zero
•  n
•  n/3
•  3n

Q5. A police car moving at 22 m/s, chases a motorcyclist. The police man sounds his horn at 176 Hz, while both of them move towards a stationary siren of frequency 165 Hz. Calculate the speed of the motorcycle, if it is given that he does not observes any beats

•  33 m/s
•  22 m/s
•  Zero
•  11 m/s

Q6. An observer moves towards a stationary source of sound with a speed 1/5th of the speed of sound. The wavelength and frequency of the source emitted are λ and f respectively. The apparent frequency and wavelength recorded by the observer are respectively

•  1.2f, λ
•  f, 1.2λ
•  0.8f, 0.8λ
•  1.2f, 1.2λ

Q7. When an engine passes near to a stationary observer then its apparent frequencies occurs in the ratio 5/3. If the velocity of engine is

•  540 m/s
•  270 m/s
•  85 m/s
•  52.5 m/s

Q8. A siren placed at a railway platform is emitting sound of frequency 5 kHz. A passenger sitting in a moving train A records a frequency of 5.5 kHz while the train approaches the siren. During his return journey in a different train B he records a frequency of 6.0 kHz while approaching the same siren. The ratio of the velocity of train B to that of train A is

•  242/252
•  2
•  5/6
•  11/6

Q9. A racing car moving towards a cliff, sounds its horn. The driver observes that the sound reflected from the cliff has a pitch one octave higher than the actual sound of the horn. If v is the velocity of sound, then the velocity of the car is

•  v/ √2
•  v/2
•  v/3
•  v/4

Q10. A person carrying a whistle emitting continuously a note of 272 Hz is running towards a reflecting surface with a speed of 18 km/hour. The speed of sound in air is 345ms–1. The number of beats heard by him is

•  4
•  6
•  8
•  3