Question

Which of the following units can be used to measure the frequency of a sound wave?

• A. hertz
• B. second
• C. second${}^{-1}$
• D. metre

Answer 1

Answer: (A), (C)

The correct options are
A hertz
C second${}^{-1}$

The number of waves produced per unit time is called frequency $\left(f\right)$. The time taken to produce one complete wave is called timeperiod $\left(T\right)$. The frequency of a wave is equal to inverse of timeperiod i.e, $f$ = $\frac{1}{T}$.
The SI unit of frequency is hertz (Hz).
1 Hz = 1 s${}^{-1}$