Question

The period of a source of a sound wave whose frequency is $400Hz$

• A. $2.5s$
• B. $2.5ms$
• C. $2.5\mu s$
• D. $25s$

Answer 1

The correct option is B $2.5ms$

Given the frequency of the wave is $f=400Hz$

We know that time period is

$T=\frac{1}{f}$

$T=\frac{1}{400}=2.5\times {10}^{-3}=2.5ms$

So B is the correct answer.