Question

Frequency of Ultrasonic waves is .................

• A. less than $20,000Hz$
• B. greater than $20,000Hz$
• C. Less than $20Hz$
• D. $1000Hz$

Answer 1

The correct option is B greater than $20,000Hz$

having a frequency above the human ear's audibility limit of about 20,000 hertz —used of waves and vibrations