Quiz for Doppler Effect

Q1: What happens to the frequency heard by a listener when a source moves toward them?

A. It increases B. It decreases C. It remains the same D. It becomes zero

Q2: Which of the following does not affect the Doppler effect?

A. Speed of sound B. Relative velocity of source and observer C. Amplitude of wave D. Frequency of source

Q3: Doppler effect occurs in which of the following?

A. Only sound waves B. Only light waves C. Both sound and light waves D. Only mechanical waves

Q4: In Doppler effect, the apparent frequency is ____ if the source and observer move toward each other.

A. Greater than real frequency B. Less than real frequency C. Equal to real frequency D. Zero

Q5: If a source moves away from an observer, the wavelength observed is:

A. Shorter B. Longer C. Unchanged D. Depends on amplitude

Q6: Which formula represents Doppler effect when source is stationary and observer moves?

A. f’ = f(v±vo)/v B. f’ = f(v±vs)/v C. f’ = f(v/(v±vs)) D. f’ = f(v/(v±vo))

Q7: In Doppler effect, when does the observed frequency become less than the actual frequency?

A. Source approaching observer B. Observer moving toward source C. Source moving away from observer D. Both move toward each other

Q8: A train blows a whistle at 500 Hz while approaching. The listener hears:

A. More than 500 Hz B. Exactly 500 Hz C. Less than 500 Hz D. No sound

Q9: When both source and observer move with the same speed in the same direction:

A. Apparent frequency is greater B. Apparent frequency is lesser C. Apparent frequency is same D. Frequency becomes zero

Q10: If speed of sound is 340 m/s, source emits 600 Hz and moves toward observer at 20 m/s, observed frequency is approximately:

A. 635 Hz B. 600 Hz C. 560 Hz D. 680 Hz

Q11: Which parameter must differ for Doppler effect to occur?

A. Temperature B. Wavelength C. Relative motion D. Pressure

Q12: Doppler effect in light shows a red shift when:

A. Source approaches observer B. Observer moves toward source C. Source moves away from observer D. Source is stationary

Q13: Doppler effect for sound is most noticeable when:

A. High frequencies are used B. Low speeds are involved C. Speed of source is more than speed of sound D. Source is at rest

Q14: When a moving source passes a stationary observer, the frequency shift:

A. Increases B. Decreases then increases C. Suddenly drops D. Suddenly rises

Q15: In Doppler effect, speed of sound depends on:

A. Frequency B. Temperature C. Amplitude D. Observer speed

Q16: The Doppler shift in frequency becomes zero when:

A. Source moves toward observer B. Observer moves away from source C. No relative motion D. Both move in opposite directions

Q17: In a vacuum, Doppler effect is observed for:

A. Sound waves B. Mechanical waves C. Electromagnetic waves D. No waves

Q18: If source and observer both move toward each other, apparent frequency is:

A. Same B. Increased C. Decreased D. Zero

Q19: In Doppler effect, frequency observed by moving observer from a stationary source is given by:

A. f × (v ± vo)/v B. f × (v ± vs)/v C. f × v/(v ± vs) D. f × v/(v ± vo)

Q20: A source emits sound of 400 Hz. Observer moves toward source with 10 m/s. Speed of sound = 330 m/s. Apparent frequency is:

A. 412 Hz B. 388 Hz C. 400 Hz D. 420 Hz

Q21: Which of these statements is false regarding Doppler effect?

A. Occurs in all waves B. Depends on source and observer motion C. Frequency increases when source recedes D. Apparent frequency changes with relative velocity