Sound multiple Choice Questions and Answers PDF - YB Study

# Sound multiple Choice Questions and Answers PDF

Given below are a few MCQs on sound class 9 which will help the students analyze their conceptual knowledge. The answers are also provided for your reference.

## Sound multiple Choice Questions answer key

1. In gases a sound wave is________

(a) Longitudinal only

(b) Transverse only

(c) both A and B

(d) None of these

2. A body produces sound only if it is______

(c) Vibration

3. If a wave complete 20 vibration in 2.5s, then its frequency is_________

(a) 200 Hz

(b) 50 Hz

(c) 20 Hz

(d) 8 Hz

4. On increasing the temperature, the speed of sound in air__________

(a) Increases

(b) Decreases

(c) Does not change

(c) First increases then becomes

5. We can easily distinguish between the sounds of the different singers even without having seen them. This is all due to the different quality or timber of their sounds. On what factor does the quality of sound depend?

(a) Wavelength

(b) Waveform

(c) Wave frequency

(d) Wave amplitude

6. Which of the following can produce longitudinal as well as transverse waves under different conditions?

(a) Bats

(c) Tuning fork

(d) None of these

7. Frequency of infrasonic waves is _______ than the frequency of ultrasound waves.

(a) less

(b) more

(c) almost same

(d) none of the above

8. When the sound gets reflected from a surface

(a) the angle of incidence < angle of reflection

(b) the angle of incidence = the angle of reflection

(c) the angle of reflection is equal to 90°

(d) the angle of incidence > angle of reflection

9. The unit of quantity on which the pitch of the sound depends is__________

(a) Hertz

(b) Metre

(c) Metre/second

(d) Second

10. The hump on the + y-axis is called crest_____

(a) The hump on the – y axis is called the crest

(b) The highest point on the hump on the + y-axis is called the crest

(c) The highest point on the hump on the – y axis is called the crest

(d) None of the above

11. Sound travels in air if_________

(a) particles of medium travel from one place to another

(b) there is no moisture in the atmosphere

(c) disturbance moves

(d) both particles as well as disturbance travel from one place to another.

12. In the region of compression or rarefaction, in a longitudinal wave the physical quantity which does not change is____________

(a) Pressure

(b) Mass

(c) Density

(d) Volume

13. Infrasound can be heard by_______

(a) dog

(b) bat

(c) rhinoceros

(d) human beings

14. Which of the following quantities is transferred during wave propagation?

(a) Energy

(b) Particles

(c) Speed

(d) Mass

15. Loudness or softness of a sound is depend on__________

(a) Amplitude

(b) Frequency

(c) Type of a wave

(d) None of these

16. Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he is adjusting

(a) the intensity of sound only

(b) the amplitude of sound only

(c) frequency of the sitar string with the frequency of other musical instruments

(d) loudness of sound

17.The speed of sound is greater in________

(a) Nickel

(b) Ethanol

(c) Air

(d) Sulphur dioxide

18. If the pendulum oscillates 78 times in one minute then the frequency of that pendulum will be____________

(a) 2 Hz

(b) 1.5 Hz

(c) 1.3 Hz

(d) 1.2 Hz

19. Children under the age of 5 years can hear sounds up to________

(a) 10 kHz

(b) 20 2Hz

(c) 25 kHz

(d) 30 kHz

20. You must have seen the doctor checking the sounds produced in the chest or heartbeat of a patient using a medical instrument called a Stethoscope. On what principle does this Stethoscope work?

(a) Multiple refractions

(b) Multiple reflections

(c) Wave motion

(d) None of these