Physics · Science General

Acoustics and Sound Waves

2,160 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 physics sound sound is produced by a vibrating body propagation of sound production and propagation of sound

Which of the following will produce sound through vibration.

  1. A plastic scale when bent over the edge of a bench

  2. Saying 'Ah' for few seconds

  3. Plucking a rubber string by fingers

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All vibration produces sound. In some cases vibrations are visible to our naked eyes but Observe that sound is produced by vibration in some cases they can only be felt not seen. In all the above activities sound can be produced.

Multiple choice physics sound sound is produced by a vibrating body propagation of sound production and propagation of sound

The waves that transfer vibrations and disturbance are

  1. Sound waves

  2. Light waves

  3. Infrared waves

  4. Ultrasonic waves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sound is a form of energy produced and transmitted by vibrating matter. Sound travels in waves. When sound moves through matter (solid, liquid, or a gas), the molecules of the matter move backward and forward in the direction in which the wave is travelling. This movement is called a vibration. Sound travels more quickly through solids than through liquids and gases because the molecules of a solid are closer together. Sound travels the lowest through gases because the molecules of a gas are farthest apart. In a vacuum sound cannot travel because there is no matter for it to move through.
Hence, the sound waves transfer vibrations or disturbance to produce sound.

Multiple choice physics sound sound is produced by a vibrating body propagation of sound production and propagation of sound

Sound is produced in a bamboo flute because:

  1. air starts vibrating

  2. bamboo starts vibrating

  3. air hits the bamboo

  4. direction of air is changed
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

   When we put air in a bamboo flute by our mouth , we give energy to the air inside the flute and air inside the bamboo flute starts vibrating and we get a sweet sound .

Multiple choice physics world of sounds sound is produced by a vibrating body propagation of sound production and propagation of sound

The membrane of a drum vibrates to produce sound. Similarly the string of a sitarvibrates to produce sound. Based on these two examples answer the following question. Which part of a whistle vibrates to produce sound?

  1. body of whistle

  2. air

  3. mouth of the person

  4. all ofthe above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The vibrations produced in the air while blowing a whistle, produces sound.

Multiple choice physics world of sounds sound is produced by a vibrating body propagation of sound production and propagation of sound

Tuning fork causes them to vibrate and produce sound. This is due to 

  1. the two metal prongs of that tuning fork

  2. the length of the prongs of that tuning fork

  3. the speed of the molecules hit the tuning fork

  4. both A and B
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

tuning  fork has two metal prongs which are vibrated and sound is produced so the answer is A.

Multiple choice physics world of sounds sound is produced by a vibrating body propagation of sound production and propagation of sound

Assuming that the period of vibration of a tuning fork depends upon the length $l$ of its prongs density $\rho$ of its material and the elastic constant  $E$ of its material what would be the formula for the period of its vibration.

  1. $\frac{k}{l}\sqrt{\frac{y}{d}}$
  2. $\frac{2k}{l}\sqrt{\frac{y}{d}}$
  3. $\frac{k}{2l}\sqrt{\frac{2y}{d}}$
  4. $\frac{3k}{l}\sqrt{\frac{y}{2d}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Considering $n=k{l}^{a}{d}^{b}{y}^{c}$--------(A) 

where k=dimensionless quantity 
l=length $=L$;  d=density$=kg/{m}^{3}$ and y=Young modulus$=kg/m{s}^{2}$
Substituting the above mentioned dimension in A we get,
$[{T]}^{-1}=[{L]}^{a}[{M{L}^{-3}]}^{b}[{M{L}^{-1}{T}^{-2}]}^{c}$
Comparing the power of $ML$  and $T$ we have,
$b+c=0$---------(1)
$a-3b-c=0$------(2)
$-2c=-1$
$c=\dfrac{1}{2}$
Putting the values of c in 1 we get,
$b=\dfrac{-1}{2}$
 Putting the values of b and c in 2 we get,
$a=-1$
Thus putting the values of a,b and c in A we get,
$n=k{l}^{-1}{d}^{1/2}{y}^{1/2}=\dfrac{k}{l}\sqrt{\dfrac{y}{d}}$ 

Multiple choice physics world of sounds sound is produced by a vibrating body propagation of sound production and propagation of sound

The membrane of a drum vibrates to produce sound. Similarly the string of a sitar vibrates to produce sound. Based on these two examples answer the following question. Which part of a whistle vibrates to produce sound?

  1. Body of whistle

  2. Air

  3. Mouth of the person

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A body of whistle is responsible for the whistle to produce sound.

As air enters the whistle at one end.As the air reaches the other, closed end, all the air molecules fill up on top of each other and cause a high pressure region.The air escapes out the little hole in the end making a sound you hear.The frequency of sound depends on the length of the whistle.

Multiple choice physics world of sounds sound is produced by a vibrating body propagation of sound production and propagation of sound

If we strike a water-filled bowl with spoon, then why there is variation in the sound produced due to change in water level of the bowl?

  1. due to change in pitch

  2. due to change in amplitude

  3. both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Due to change in air column the wavelength and fundamental frequency changes. So the pitch of the sound changes which results in difference in the produced sounds .

so the answer is A.

Multiple choice the nature of electromagnetic waves space exploration and forms of light observing space: telescopes electromagnetic waves physics

In which of the following media can non-mechanical waves travel?

  1. In vacuum as well as in a medium

  2. In vacuum but not in a medium

  3. In a medium but not in a vacuum

  4. Neither in a medium nor in vacuum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Non mechanical waves are waves that do not require a medium for transfer of their energy to occur electromagnetic waves are the only type of non mechanical waves.

Non mechanical waves can travel both in vacuum or in any medium