Tag: physics

Questions Related to physics

Which kind of sound is produced in an earthquake before the main shock wave begins?

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

  1. ultrasonic sound

  2. infrasonic sound

  3. audible sound

  4. none of the above

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Correct Option: B
Explanation:

Infrasonic waves are waves whose frequency is below 20Hz. These sounds are not heard by human ears. Audible sounds are between 20 Hz and 20,000 Hz.

We do not hear the screams of a bat because:

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

  1. screams are below 30,000 Hz

  2. the screams are infra sonic

  3. the screams are ultra sonic

  4. all

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Correct Option: C
Explanation:

This is because the screams are ultrasonic(above 20,000 hertz) which human ear cannot hear.

Bats detect the obstacle in their path by receiving the detected:

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

  1. infrasonic waves

  2. ultrasonic waves

  3. both

  4. none

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Correct Option: B
Explanation:

Bats can produce ultrasonic waves by flapping their wings.
They can also detect these waves.these waves produced by the bats after reflection from the obstacles like building guide them to  remain away from the obstacles during night with the help of ultrasonic waves.

Three different vibrating objects produce three types of sounds X, Y and Z.
Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily.
The sound X is used for echocardiography.The sound similar to that which is produced during an earthquake before the main shock wave is generated.
Name one device in a science laboratory which can produce sound like Y.

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

  1. simple pendulum.

  2. tuning fork

  3. glass

  4. all of the above

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Correct Option: A
Explanation:

Ultrasound is used in echocardiography. In this ultrasound are used to construct the image of heart. Ultrasounds and infrasounds are not audible to man. Ultrasound have frequency more than 20 kHz.
Infrasound have frequency below 20 Hz.
Y is infrasound .

The frequency, from the following list, which is not audible to the human ear is:

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

  1. 50 Hz

  2. 500 Hz

  3. 5000 Hz

  4. 50000 Hz

Show answer
Correct Option: D
Explanation:

The waves having frequency between 20Hz and 20,000Hz are known as sound waves. Thus the audible range of frequency is 20Hz to 20,000Hz.

Which of the following sounds is not audible?

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

  1. A tuning fork vibrating 400times in 2s

  2. A tuning fork vibrating 3600 times in 60s

  3. Tuning fork vibrating 1time in 1 s

  4. Tuning fork vibrating 900 times in 2s

Show answer
Correct Option: C
Explanation:

The range of audible frequency is 20 Hz to 20,000 Hz. In the first case frequency of the tuning fork will be 200Hz. In second case it will be 60Hz and In third case frequency will be 1 Hz ,which is out of the audible frequency range. In fourth case frequency is 450 Hz which is again in the audible range.

Rats also play games by producing __________.

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

  1. ultrasonic sound

  2. infrasonic sound

  3. audible sound

  4. all of the above

Show answer
Correct Option: A
Explanation:

Frequencies higher than 20 kHz are called ultrasonic sound or ultrasound. Ultrasound is produced by dolphins, bats and porpoises. Moths of certain families have very sensitive hearing equipment. These moths can hear the high frequency squeaks of the bat and know when a bat is flying nearby, and are able to escape capture. Rats also play games by producing ultrasound.

Three different vibrating bodies produce three types of sounds X, Y and Z.
Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. 
The sound X is used in for monitoring nuclear reactor. The sound similar to that which is produced during an earthquake before the mainshock wave is generated.


What type of sounds are (i) X (ii) Y, and (iii) Z?

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

  1. X - infrasound, Y - ultrasound, Z - audible sound

  2. X - audible sound, Y - infrasound, Z - ultrasound

  3. X - ultrasound, Y - infrasound, Z - audible sound

  4. X - infrasound, Y - audible sound, Z - audible sound

Show answer
Correct Option: C
Explanation:

Ultrasound is used to see what is happening in a nuclear reactor. Ultrasounds and infrasounds are not audible to man. Ultrasound have frequency more than 20 kHz.
Infrasound have frequency below 20Hz.

If a vibration is produced 200 times per second :

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

  1. it will be audible by the human ear

  2. it will not be audible by the human ear

  3. it will be audible depending on its amplitude

  4. none of these

Show answer
Correct Option: A
Explanation:

It will be audible by the human ear because vibration is produced 200 times/second. So,frequency =200Hz. And the range of audible frequency is 20Hz-20,000Hz. 

We are able to hear the sounds made by a source if the frequency of sound is:

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

  1. Within audible range in air

  2. Within audible range in vaccum

  3. Within audible range in water

  4. Within audible range in ${ CO } _{ 2 }$

Show answer
Correct Option: A
Explanation:

The human ear can not hear all frequency of sounds. The audible range of the frequency is 20 Hz to 20000 Hz. The human ear is able to hear the sounds those have frequencies in that audible range.