Which of the following correctly defines ultrasound?

PHYSICS · Single correct · CBSE · Physics · Sound · Sound

Problem

Which of the following correctly defines ultrasound? (a) Sound waves with frequency greater than

2\,\text{kHz}

(b) Sound waves with frequency between

20\,\text{Hz}

and

20\,\text{kHz}

20\,\text{kHz}

(d) Sound waves with wavelength shorter than

17\,\text{cm}

in air