Tag: study of sound

Questions Related to study of sound

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 a range of hearing but sound Z can be heard easily.  

The sound X is used in a hospital to break kidney stones of a patient into fine grains which then get flushed out with Urine. The sound similar to that which is produced during an earthquake before the main shock wave is generated. What is the frequency range of sounds like Z?

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

  1. 20 - 20,000 Hz

  2. 20,000-50000Hz

  3. 2-10Hz

  4. all

Show answer
Correct Option: A
Explanation:

Ultrasound is used for removing kidney stones.when ultrasound are targeted on such stone,the stones start vubrating at high frequency.the stone due to this vibratory motion. Breakdown into fine particles.ultrasounds and infrasounds are not audible to man.ultrasound have frequency more than 20kHz.



Infrasound have frequency below 20Hz, X is ultrasound. Y is infrasound, Z is audible sound.


Audible sound has frequency between 20Hz -20,000Hz. 

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

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

  1. ${10}^{-3}m$

  2. ${10}^{-2}m$

  3. $1 m$

  4. ${10}^{2}m$

Show answer
Correct Option: C
Explanation:

Human ears can sense sound waves travelling in air whose frequencies $f$ lie in the range of $20Hz$ to $20kHz$

The average speed $v$ of sound in air is $335m/s$
Wavelength $\lambda=\cfrac vf$
Hence the wavelength range of audible sounds is $\cfrac{335}{20000}$  $to$  $\cfrac{335}{20}$
That is $1.675\times{10^{-2}}$ metres to $16.75$ metres
You can see that among all the 4 options given, only $1m$ fits in the audible range.

Voices of men, Women and children different because of

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

  1. The pitch

  2. The length and the thickness of vocal cords.

  3. Both

  4. None

Show answer
Correct Option: C
Explanation:

The voices of men, women and children differ from each other
due to the following factors:

i) The pitch is one of the most essential factors to determine the voice of the individual. For example, men have lower-pitched voices while women have higher-pitched voices.

(ii) Second factor which brings in the difference in the voices is the length and the thickness of vocal cords.  from each other due to the following factors

 State True or False.

All inaudible sounds produces frequencies less than 20 Hz.

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

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

The frequency range of audible sound is $20 Hz$ to $20000 Hz$. Thus, the sound below the frequency 20 Hz is inaudible for human ear and the sound above the frequency 20000 Hz is inaudible for human ear. Thus, the given statement is false.