Sound waves of a frequency beyond the hearing range of the human ear are referred toas ultrasonic waves or vibrations, and the term embraces all vibrational waves of frequency greater than approximately:

Sound waves of a frequency beyond the hearing range of the human ear a

1.	Sound waves of a frequency beyond the hearing range of the human ear are referred toas ultrasonic waves or vibrations, and the term embraces all vibrational waves of frequency greater than approximately:
A.	20 kHz
B.	2 MHz
C.	2 kHz
D.	200 kHz
Answer» B. 2 MHz