Ultrasonics are sound waves of frequency
- AGreater than 20,000 Hz
- BLess than 10,000 Hz
- CEqual to 1000 Hz
- DNone of these
Show answer and explanation
Correct answer: (a) Greater than 20,000 Hz
Explanation
Ultrasonic waves have frequency greater than 20,000 Hz (20 kHz), above the upper limit of human hearing.
The audible range for humans is 20 Hz to 20,000 Hz; sounds below 20 Hz are infrasonic.
Ultrasonics are used in sonography, distance measurement and flaw detection.