Question

(a) What is ultrasound ? What is the difference between ordinary sound and ultrasound ?
(b) Write any three applications (or uses) of ultrasound.

Answer 1

(a) Ultrasound waves are high-frequency sound waves. Due to higher frequency, they can penetrate into matter to a large extent.
We can differentiate between ordinary and ultrasonic waves as:

Audible sound waves	Ultrasound waves
They have a frequency range of 20 Hz–20,000 Hz	They have frequencies above 20,000 Hz
These sounds are audible to human ears.	These sounds are inaudible to human ears.

(b) We have the following applications of ultrasound:
(i) Ultrasound is used in industry for detecting flaws in metal blocks without damaging them.
(ii) Ultrasound is used in hospitals as a medical checkup to investigate the internal organs of the human body such as liver, kidneys, and uterus.
(iii) Ultrasound is used to monitor the growth of fetus inside the mother’s uterus.