Question

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 in hospitals to break kidney stones of a patient into fine grains which then get flushed out with urine. The sound Y is similar to that which is produced during an earthquake before the main shock wave is generated.

(a) What type of sounds are (i) X (ii) Y, and (iii) Z ?
(b) Name one device which can produce sound like X.
(c) Name one device in a science laboratory which can produce sound like Y.
(d) Name one device in our homes which can produce sound like Z.
(e) What is the frequency range of sounds like Z ?

Answer 1

(a)
(i) X is an ultrasonic sound as it is used in hospitals to break the kidney stones.
(ii) Y is an infrasonic sound as it is produced during the earthquake.
(iii) Z is an audible sound as it can be easily heard.

(b) Ultrasound machine in hospitals is used to produce ultrasonic sound waves.

(c) Simple pendulum can produce infrasonic sound waves.

(d) Loudspeaker can produce sound of audible range.

(e) Since Z is an audible sound, its frequency range is between 20 Hz and 20,000 Hz.