Tag: sound: production of sound

Questions Related to sound: production of sound

A man fires a gun and hears the echo after $2\,\frac{1}{2}sec$. If the velocity of sound in air is $340ms^{-1}$ his distance from the cliff causing the echo is 

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. $2\,\frac{1}{2}km$

  2. $425m$

  3. $850m$

  4. $136m$

Show answer
Correct Option: B

A sound wave of pressure amplitude $5$ pascal propagates through the air medium. The normal pressure of air is $1.0\times10^5 N/m^2$. The difference between maximum and minimum pressure in the medium is 

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. $5\times10^5 N/m^2$

  2. $10\times10^5 N/m^2$

  3. $10 N/m^2$

  4. $None\ of\ these$

Show answer
Correct Option: C

A siren emitting a sound of frequency $1000 Hz$ moves away from you towards a cliff at a speed of $10 m/s$ [speed of sound in air $330 m/s$] Then. 

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. The frequency of the sound you hearing coming directly from the siren is $ \dfrac {33}{34} \times 1000 Hz $.

  2. The frequency of the sound you hearing coming directly from the siren is $ \dfrac {33}{32} \times 1000 Hz $.

  3. The frequency of the sound you hear reflect off the cliff $ \dfrac {33}{32} \times 1000 Hz $.

  4. The frequency of the sound you hear reflect off the cliff $ \dfrac {33}{34} \times 1000 Hz $.

Show answer
Correct Option: C

A person moving in a car with a velocity of $36kmph $ towards a fort wall blows a horn. If he hears the echo after $3s$, the distance of the wall from him. when he blows then horn (velocity of sound $340ms^P{-1}$)

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. $340m$

  2. $1050m$

  3. $700m$

  4. $525m$

Show answer
Correct Option: D

Bats detect the obstacles in their path by receiving the reflected

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. infrasonic waves

  2. ultrasonic waves

  3. micro waves

  4. radio waves

Show answer
Correct Option: B
Explanation:

Answer is B.

Most bats produce echolocation sounds by contracting their larynx (voice box). A few species, though, click their tongues. These sounds are generally emitted through the mouth. Echolocation calls are usually ultrasonic, ranging in frequency from 20 to 200 kilohertz (kHz), whereas human hearing normally tops out at around 20 kHz.
While using echolocation, the bats emit a series of short, high-frequency sounds from their mouths or nostrils that bounce off objects and surfaces and then return to the animals ears. Since high-frequency waves do not diffract, or bend, extensively, these ultrasonic vibrations provide bats with accurate maps of their surroundings. 

Echocardiography is used to diagnose heart diseases which utilises infrasonic waves.

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient

Show answer
Correct Option: B
Explanation:

An echocardiogram (also called an echo) is a type of ultrasound test that uses high-pitched sound waves that are sent through a device called a transducer. The device picks up echoes of the sound waves as they bounce off the different parts of your heart. These echoes are turned into moving pictures of your heart that can be seen on a video screen.
Hence, the statement is false.

The frequency of a wave is 5 Hz. It refers to (type of wave) ___________.

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. ultrasonics

  2. microwaves

  3. infrasonics

  4. radio waves

Show answer
Correct Option: C
Explanation:

The waves below the frequency of 20 Hz are infrasonic waves. So, the wave of 5 Hz is also an infrasonic wave.

Sound of frequency below $20 \ Hz$ is called

physics range of hearing sound: production of sound audible, infrasonic and ultrasonic sounds different sounds

  1. audio sounds

  2. infrasonic

  3. ultrasonic

  4. supersonics

Show answer
Correct Option: B
Explanation:

Sound waves are categorized on the basis of their frequency range.

Sound of frequency below $20 \ Hz$ is called as infrasonic. Sound of frequency above $20 \ kHz$ is called as ultrasonic whereas sound of frequency in between $20 \ Hz$ to $20 \ kHz$ is called as audio sound.

When sound wave is refracted from air to water, which of the following will remain unchanged?

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. wave number

  2. wavelength

  3. wave velocity

  4. frequency

Show answer
Correct Option: D
Explanation:

Frequency of a wave is characterised by the source of wave, therefore it will not be affected by change in medium . 

Ultrasound has frequency of vibration .....

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. between 20 Hz and 20000 Hz.

  2. below 20 Hz.

  3. above 20000 Hz.

  4. between 500 Hz and 10000 Hz.

Show answer
Correct Option: C
Explanation:

The term "Ultrasound" refers to the sound having frequency greater than the human audible frequency. Maximum limit of the human audible sound is $20000$ Hz.

So, ultrasound has  frequency of vibration above $20000$ Hz.