The frequency of ultrasound wave is typically (a)Above 20 kHz (b)Above 20000 kHz (c)Below 20 kHz (d)Below 02 kHz
Option A. Ultrasound refers to a valid wave with a frequency extra than the top restriction of human hearing, that's commonly over 20 kHz. In general, human beings can listen sounds with a frequency among 20 Hz and 20 kHz.
