subject

Doppler Effect

Physics ⇒ Waves and Sound

Doppler Effect starts at 11 and continues till grade 12. QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Doppler Effect. How you perform is determined by your score and the time you take. When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 12
A car is moving at 20 m/s towards a stationary observer. The car's horn emits a sound at 440 Hz. The speed of sound is 340 m/s. What frequency does the observer hear?
A police car is moving towards a stationary observer at 40 m/s, emitting a siren at 600 Hz. The speed of sound is 340 m/s. What is the observed frequency?
A sound source moves away from a stationary observer at 25 m/s. The speed of sound is 340 m/s and the source frequency is 700 Hz. What is the observed frequency?
A source emits sound at 1000 Hz. An observer moves towards the source at 30 m/s. The speed of sound is 330 m/s. What is the observed frequency?
A stationary observer hears a frequency of 450 Hz from a source moving towards them at 15 m/s. The speed of sound is 330 m/s. What is the emitted frequency of the source?
A stationary source emits sound at 400 Hz. An observer moves away from the source at 20 m/s. If the speed of sound is 340 m/s, what frequency does the observer hear?
A train approaches a stationary observer at 30 m/s. The speed of sound is 340 m/s and the train's whistle emits a frequency of 500 Hz. What frequency does the observer hear?
Describe the difference between the Doppler Effect for sound and for light.
Describe what is meant by 'redshift' and 'blueshift' in the context of the Doppler Effect for light.
Explain why the Doppler Effect is important in medical imaging.
Explain why the Doppler Effect is not observed when the source and observer are stationary relative to each other.
Explain why the Doppler Effect is not symmetrical for sound waves when the source and observer move at the same speed but in opposite directions.
Explain why the pitch of an ambulance siren appears to change as it passes by an observer.
The formula for the observed frequency f' when the source moves towards a stationary observer is f' = f \frac{v}{v - v_s} . Identify what each symbol represents.
What is the Doppler Effect?