Physics Questions and Answers Part-17

1. The number of waves per second in a sound is called ________ of that sound.
a) Velocity
b) Frequency
c) Displacement
d) Acceleration

Answer: b
Explanation: The number of waves per second in a sound is called frequency of that sound.

2. Sound waves do not show the phenomenon of
a) Refraction
b) Interference
c) Diffraction
d) Polarisation

Answer: d
Explanation: As sound waves are longitudinal waves, they don't exhibit Polarization phenomenon, which is exhibited by the transverse wave only.

3. Speed of sound is maximum in which among the following?
a) Gases
b) Vaccum
c) Liquids
d) Solids

Answer: d
Explanation: We know that, in solids all the particles are packed together and hence sound can travel from one to one very fast. Hence, speed of sound is maximum in solids and decreases from solids to liquids and liquids to gases. Sound can't travel through vacuum.

4. The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because
a) The ringing is not loud enough
b) The glass of the bell jar absorbs the sound waves
c) The bell jar is too small
d) There is no air or any other gas in the bell jar

Answer: d
Explanation: The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because there is no air or any other gas in the bell jar.

5.What is the full form of "RADAR" ?
a) Radio Detecting and Ranging
b) Region Device and Ranging
c) Radio Detect and Rangs
d) Radio Device and Ranging

Answer: a
Explanation: Radio Detecting and Ranging is the full form of "RADAR".

6. What is the SI unit of intensity of sound?
a) Decibel
b) Newton
c) Heartz
d) Tesla

Answer: a
Explanation: Decibel is the SI unit of intensity of sound.

7. Sound cannot pass through
a) water
b) steel
c) air
d) Vacuum

Answer: d
Explanation: Sound cannot travel through a perfect vacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibration to work in.

8. Sound waves cannot travel in
a) vucum
b) water
c) glass
d) Hydrogen gas

Answer: a
Explanation: Sound cannot travel through a perfect vacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibration to work in.

9. The quality or tone of a musical sound produced by a stringed instrument depends on
a) Frequency of vibration
b) Length of the strings in the instrument
c) Amplitude of vibration
d) Wave form of the sound

Answer: d
Explanation: The timbre or quality of a sound depends on its wave form, which varies with the number of overtones, or harmonics, that are present, their frequencies, and their relative intensities. In simple terms, timbre is what makes a particular musical sound have a different sound from another, even when they have the same pitch and loudness.

10. Which determines the frequency of a sound wave?
a) Amplitude
b) speed
c) Source
d) medium

Answer: a
Explanation: Amplitude determines the frequency of a sound wave.