# Doppler effect MCQ for NEET | free Pdf

Practicing our Doppler effect MCQ for Class 12 with Answers is one of the best ways to prepare for the NEET exam. By practicing more Physics MCQs with Answers Pdf Download, students can improve their speed and accuracy which can help them during class 12 board exam.

## MCQs on Doppler effect for Class 12

1. Doppler effect is not applied to__________

(a) sound waves

(b) micro waves

(c) matter waves

(d) electromagnetic waves

2. When a source of light moves towards the observer with a certain speed, the observer receives________

(a) a light of lower frequency

(b) a light of higher frequency

(c) a light of higher wavelength

(d) light of the original frequency

3. When a source light moves away from the observer, there is_________

(a) a decrease in the wavelength of light

(b) an increase in the wavelength of light

(c) no change is the wavelength of light

(d) an increase in the frequency of light

4. A blowing whistle emitting a note of frequency 100 Hz is moved horizontally along the circumference of a circle of radius R. If a man is standing at the centre of the circle, then he will___________

(a) hear a variations in the frequency of sound in one round

(b) not hear any sound

(c) hear a sound of the same frequency

(d) hear the beats

5. The colour of a star is changing from blue to red. This indicates that the star is_______

(a) approaching the earth

(b) going away from the earth

(c) is stationary

(d) emitting waves of only blue and red lights

Read : MCQs on Gravitation

6. With what velocity should an observer move relative to a Statonary source so that he may hear a sound of double  theactual frequency of the source_______

(a) half the speed of sound

(b) equal to the speed of sound

(c) double the speed of sound

(d) thrice the speed of sound

7. Find the ‘wrong’ statement from the following

Doppler effect will not be observed if_____

(a) both the source and the observer are stationary

(b) the relative velocity bet ween the source and the observer is zero

(c) the source or the observer are moving at supersonic

speeds

(d) the speeds of the source and the sound are different but they are less than the speed of sound

8. Source is moving away from observer, observed frequency of light will be .. actual frequency of light emitted by the source________

a) less than

(b) greater than

(c)  same as

(d) doubled

9. Apparent wavelength of light reachingg to observer is greater than its actual value, source is moving_______

(a) towards observer

(b) away from observer

(c) either ‘a’ or ‘b’

(d) neither ‘a’ nor ‘b

Read : Uniform Circular Motion MCQs for NEET

10. Doppler shift in wavelength is 4A° when a star is moving towards earth with a velocity 4×10⁵ m/s. Wavelength of light emitted by star is________

(a) 4000 A°

(b) 6000 A°

(c) 3000 A°

(d) 8000 A°

11. Frequeny of star moving away from earth with a speed of 5 x 10⁷ m/s appear to be 6.4 x 10¹⁴ Hz. Frequency of star is_________

(a) 7.6 x 10¹⁴ Hz

(b) 6.4 x 10¹⁴ Hz

(c) 8.2 x 10¹⁴ Hz

(d) 5 x 10¹⁴ Hz

12. Frequency of a source moving towards object is 4 x 10¹⁴ Hz with a velocity 1.2 x 10⁷ m/s Doppler shift in frequency is_________

(a) 16 x 10¹⁴ Hz

(b) 16 x 10¹² Hz

(c) 1.6 x 10¹² Hz

(d) 1.6x 10² Hz

Read : Solid state MCQs for NEET

13. Find the wrong statement from the following:

The relative speed between a source of sound and the observer is zero but the wind is blowing with a velocity Vw from the source to the observer. In this case_________

(a) there is no change in the frequency of the sound heard

(b) the velocity of sOund is increased from V + Vw

(c) the wavelength of sound heard is decreased

(d) the wavelength of sound heard is increased

14. Two sources of sound A and B kept at a certain distance.produce sound waves ot the same Irequency (n). An

observer starts running from A and goes towards B. Then during his journey from A to B _________

(a) he will hear sound notes of the same frequency

(b) the sound received from A will be always of a frequency which is higher thann

(c) the sound received from B will be always of a frequency which is lower than n

(d) he will hear beats it the difference in apparent frequencies is small

15. Doppler’s effect is not observed when the speed of the sound is________

(a) equal to the speed of the sound

(b) is less than speed of sound

(c) is more than the speed of sound

(d) Zero

16. Doppler’s effect is not applicable when the speed of the source of sound is_________

(a) zero

(b) equal to the speed of the sound

(c) less then the speed of the sound

(d) more than the speed of sound

17. Radio waves are sent towards a moving aeroplane by a radar and the reflected waves are received by the radar. If the aeroplane is moving towards the radar, then the wavelength of the reflected wave__________

(a) Increases

(b) Decreases

(c) Both A and B

(d) None