Physics · Science General

Acoustics and Sound Waves

2,006 Questions

Acoustics and sound waves deal with mechanical vibrations traveling through media like air and water. Key concepts include wave reflection, beats, echoes, the Mach number, and infrasound. These physics fundamentals are regularly tested in general science sections of multiple competitive exams.

Sound wave propagationEchoes and reflectionWave interferenceMach numberInfrasound frequency

Acoustics and Sound Waves Questions

Multiple choice

Which of the following statements is/are false? a. Sound is produced when an object moves to and fro rapidly. b. The energy required to make an object vibrate and produce sound is produced by some outside source. c. Sound of a radio speaker is produced due to the vibrating air columns of the speaker.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option, as this statement is false. Sound of a radio speaker is not produced due to the vibrating air columns of the speaker. It is due to the vibrations of the cone of speaker.

Multiple choice

Due to which of the following reasons, sound cannot be heard on the surface of moon?

a. Due to absence of gravity. b. Due to absence of air on moon. c. Due to uneven terrain on moon.

  1. Only a and b

  2. Only a

  3. Only b and c

  4. Only b

  5. Only c
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct option. Sound waves need a medium to travel. As there is no air on moon, there is no medium for air waves to travel. Thus, sound cannot be heard on the surface of moon. 

Multiple choice

Which of the following statements is/are false?

a. The function of anvil in the middle ear is to pass the vibrations from the hammer to the stirrup. b. The outer part of the ear is called pinna and is attached to a long passage called ear canal. c. Three tiny bones in the middle part of the ear act as a system of levers and amplify sound vibrations coming from the cochlea.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct answer option as this is an incorrect statement. Three tiny bones in the middle part of the ear act as a system of levers and amplify sound vibrations coming from the ear drum, and not cochlea.

Multiple choice

Which of the following statements is/are false:

a. When an object vibrates, then the air around it also starts vibrating in exactly the same way and carries the sound to our ears through the vibration of its molecules. b. Human beings produce sound by using the voice box which is called the 'cochlea'. c. The human voice box contains two ligaments known as the vocal cords which produce sound due to their vibrations.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option as this is a false statement. Human beings produce sound by using the voice box which is called the 'larynx', and not the 'cochlea'.

Multiple choice

The different sounds produced by different singers or different musical instruments can be distinguished on the basis of a characteristic of sound called ____________.

  1. frequency

  2. pitch

  3. loudness

  4. timbre

  5. none of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct option. Sounds produced by different singers or different musical instruments can be distinguished on the basis of a characteristic of sound called timbre. Timbre of sound is the combination of qualities of a sound that distinguishes it from other sounds with same pitch and volume.

Multiple choice

Which of the following statements is/are false? a. The loudness of sound depends upon the amplitude of vibrations of the vibrating object. b. The loudness of sound is inversely proportional to the square of amplitude of vibrations of the sound producing object. c. The pitch of sound is directly proportional to its frequency.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option, as the statement is false. The loudness of sound is directly proportional to the square of amplitude of vibrations of the sound producing object. If the amplitude of vibrations is doubled. then the loudness will become four times and if the amplitude of vibrations is halved, then the loudness will become one-fourth. 

Multiple choice

Decibel is a term connected with which of the following physical factors?

  1. Air volume

  2. Water

  3. Sound

  4. Soil

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Intensity of sound is measured in decibles. The decibel measures sound pressure or electrical pressure (voltage) levels. It is a logarithmic unit that describes the ratio of two intensities, such as two different sound pressures, two different voltages and so on.

Multiple choice

Sound travels fastest through _________.

  1. Steel

  2. Air

  3. Vacuum

  4. Water

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sound travels fastest in solids. This is because the molecules in solids are close together, which makes it easier for the vibrations to pass from one molecule to the next.Speed of sound : Metal (5000 m/s).