Tag: range of hearing

Questions Related to range of hearing

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 

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

  2. $425m$

  3. $850m$

  4. $136m$


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 

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

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

  3. $10 N/m^2$

  4. $None\ of\ these$


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. 

  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 $.


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 $340ms^P{-1}$)

  1. $340m$

  2. $1050m$

  3. $700m$

  4. $525m$


Correct Option: D

Bats detect the obstacles in their path by receiving the reflected

  1. infrasonic waves

  2. ultrasonic waves

  3. micro waves

  4. radio waves


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.

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient


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) ___________.

  1. ultrasonics

  2. microwaves

  3. infrasonics

  4. radio waves


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

  1. audio sounds

  2. infrasonic

  3. ultrasonic

  4. supersonics


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.

The sounds having frequency less than 20 Hz are called ultrasonics.

  1. True

  2. False


Correct Option: B
Explanation:

Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear.

so the answer is B.

Human ears can sense sound wave travelling in air having wavelength of ................... .

  1. $10^{-3}$ m

  2. $10^{-2}$ m

  3. 1 m

  4. $10^{2}$ m


Correct Option: C
Explanation:

The audible wave length range of human beings in (16.5 mm - 16.5 m)
Hence 1 m is the correct option.