Tag: study of sound

Questions Related to study of sound

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

  1. infrasonic waves

  2. ultrasonic waves

  3. both

  4. none


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.

  1. simple pendulum.

  2. tuning fork

  3. glass

  4. all of the above


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:

  1. 50 Hz

  2. 500 Hz

  3. 5000 Hz

  4. 50000 Hz


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?

  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


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 __________.

  1. ultrasonic sound

  2. infrasonic sound

  3. audible sound

  4. all of the above


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?

  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


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 :

  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


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:

  1. Within audible range in air

  2. Within audible range in vaccum

  3. Within audible range in water

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


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.   

A pendulum vibrates with a time period of 1 second. What kind of sound is produced by it?

  1. Supersonic

  2. Audible

  3. Infrasonic

  4. Ultrasonic


Correct Option: C
Explanation:

The low frequency vibration of infrasonic wave is less than $20\,Hz$. The pendulum vibrates at this low frequency with a time period of $1$ second.

How are bats able to fly in the dark?

  1. They produce infrasonic waves.

  2. They can hear ultrasonic sounds.

  3. They produce infrared waves.

  4. They can hear infrared waves.


Correct Option: B
Explanation:

Bats emit ultrasonic sound waves which bounces back from the objects and enables them to sense an obstruction and also hunt for prey.