Tag: study of sound

Questions Related to study of sound

It has been seen that the behaviour of animals becomes unusual just before the tremor is felt.what is the reason behind this?

physics study of sound conditions for hearing echo echo ultrasound and its applications

  1. Because animals are able to detect infrasonic waves produced at the time of tremor.

  2. Because animals are able to detect ultrasonic waves produced at the time of tremor.

  3. Because animals are able to detect audible waves produced at the time of tremor.

  4. All

Show answer
Correct Option: A
Explanation:

Has been seen that the behaviour of animals becomes unusual just before the tremor is felt.This is because animals are able to detect infrasonic waves produced at the time of tremor. Infrasonic waves are waves of frequency less than 20Hz.

State whether given statement is True or False
Sonar make use of ultrasound.

physics study of sound reverberation applications of reflection of sound applications of ultrasound

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Answer is A.
Ultrasound is sound with a frequency higher than 20 kHz. This is above the human range of hearing. The most common use of ultrasound, creating images, has industrial and medical applications.
Sonar illustrates how a ship on the ocean utilizes the reflecting properties of ultrasound waves to determine the depth of the ocean. A ultrasound wave is transmitted and bounces off the seabed. Because the speed of sound is known and the time lapse between sending and receiving the sound can be measured, the distance from the ship to the bottom of the ocean can be determined. This technique is called sonar (originally an acronym for SOund Navigation And Ranging).

In SONAR, we use

physics study of sound reverberation applications of reflection of sound applications of ultrasound

  1. ultrasonic waves

  2. infrasonic waves

  3. radio waves

  4. audible sound waves

Show answer
Correct Option: A
Explanation:

Answer is A.

Sonar illustrates how a ship on the ocean utilizes the reflecting properties of ultrasound waves to determine the depth of the ocean. A ultrasound wave is transmitted and bounces off the seabed. Because the speed of sound is known and the time lapse between sending and receiving the sound can be measured, the distance from the ship to the bottom of the ocean can be determined. This technique is called sonar (originally an acronym for Sound Navigation And Ranging).

SONAR is

physics study of sound reverberation applications of reflection of sound applications of ultrasound

  1. SOund Navigation And Ranging

  2. SOund Nullyfying And Ranging

  3. SOund Navigation with Amplitude and Ranging

  4. None

Show answer
Correct Option: A
Explanation:

SONAR is the best example that illustrates how a ship on the ocean utilizes the reflecting properties of sound waves to determine the depth of the ocean. A sound wave is transmitted and bounces off the seabed. Because the speed of sound is known and the time lapse between sending and receiving the sound can be measured, the distance from the ship to the bottom of the ocean can be determined. This technique is called sonar (SOund Navigation And Ranging).

In a good auditorium the reverberation time is

physics study of sound reverberation applications of reflection of sound applications of ultrasound

  1. 0.17 V/A

  2. > 0.17 V/A

  3. < 0.17 V/A

  4. none of these

Show answer
Correct Option: C
Explanation:

The time for which sound continues to be heard (due to persistence) after the source has stopped producing the sound is called reverberation time . Sabine gave a formula for reverberation time of a good building , which is 

               $T=0.16V/A$ ,
where $V=$ volume of building in cubic metre ,
           $A=$ total absorption of building ,
hence option C is correct .


State whether given statement is True or False
It is usually preferable to have a longer reverberation time in an auditorium for music than one for speeches.

physics study of sound reverberation applications of reflection of sound applications of ultrasound

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

The reverberant sound in an auditorium dies away with time as the sound energy is absorbed by multiple interactions with the surfaces of the room. In a more reflective room, it will take longer for the sound to die away and the room is said to be 'live'. In a very absorbent room, the sound will die away quickly and the room will be described as acoustically 'dead'. But the time for reverberation to completely die away will depend upon how loud the sound was to begin with, and will also depend upon the acuity of the hearing of the observer.
The desirable range of reverberation times for general purpose auditoriums is about 1.5 to 2.5 seconds. Longer reverberation times are sometimes desirable for music and shorter reverberation times are better if the auditorium is to be used for speech only.
Rooms used for speech typically need a shorter reverberation time so that speech can be understood more clearly. If the reflected sound from one syllable is still heard when the next syllable is spoken, it may be difficult to understand what was said. On the other hand the reverberation time is too short, tonal balance and loudness may suffer.
Basic factors that affect a room's reverberation time include the size and shape of the enclosure as well as the materials used in the construction of the room. Every object placed within the enclosure can also affect this reverberation time, including people and their belongings.
Hence, a longer reverberation time is preferred in an auditorium for music than one for speeches.

The device/instrument which does not work on the multiple reflections of sound waves is:

physics study of sound reverberation applications of reflection of sound applications of ultrasound

  1. Mega phone

  2. Sound board

  3. Guitar

  4. Stethoscope

Show answer
Correct Option: C
Explanation:

except guitar all the listed instruments work on multiple reflections of sound guitar works on vibration of strings 

so the answer is C.

Why the ceiling of concert halls, cinema halls made curved?

physics study of sound reverberation applications of reflection of sound applications of ultrasound

  1. to make the hall beautiful.

  2. for proper light conditions.

  3. so that the sound can reach all corners properly.

  4. So that the picture or the stage can be visible to each and energy person.

Show answer
Correct Option: C
Explanation:

In concert halls, cinema halls, conference halls, the ceiling are made curved, so that the sound after reflection from the curved surface reaches all corners of the hall evenly.

A sound waves having certain frequency travels with a speed of 336 m/s and wavelength 3 cm. Calculate the frequency. Will it be audible?

audible, infra and ultra sound with its application study of sound physics

  1. $1120 Hz,\ Yes$

  2. $11200 Hz,\ Yes$

  3. $11200 Hz,\ No$

  4. $1120 Hz,\ No$

Show answer
Correct Option: B
Explanation:

The relationship between frequency, speed of sound and wavelength of a sound wave is given as 

$Frequency=\dfrac { Speed\quad of\quad sound }{ Wavelength } \quad $.

Therefore, $Frequency,\quad \nu =\dfrac { 336\quad m/s }{ 0.03\quad m } \quad $, given that the speed of sound is 336 m/s and wavelength is 3 cm, that is 0.03 m.

$Frequency\quad \nu =11200\quad Hz\quad$.

Hence, the frequency of the sound wave is 11,200 Hz which audible because the human auditory system is sensitive to frequencies from about 20 Hz to a maximum of around 20,000 Hz.

Name the sounds of the frequencies given below $100Hz$.

audible, infra and ultra sound with its application study of sound physics

  1. $audible$

  2. $inaudible$

  3. $unbreakable$

  4. None of the above

Show answer
Correct Option: A
Explanation:

The generally accepted standard range of audible frequencies is 20 to 20,000 Hz, although the range of frequencies individuals hear is greatly influenced by environmental factors.
Hence, 100 Hz is an audible sound.