The sound from a mosquito is produced when it vibrates its wings at an average rate of 500 vibrations per second. What is the time period of the vibration?

Given,

Total number of vibrations = 500

Total time taken = 1 s

We know,

Time period = $\dfrac{1}{\text{Frequency}}$ and

Frequency = $\dfrac{\text{Total number of oscillations}}{\text{Total time taken}}$

Hence,

Time period = $\dfrac{\text{Total time taken}}{\text{Total number of oscillations }}$

Substituting we get,

Time period = $\dfrac{1}{500}$ = 0.002 s

So, time period = 0.002 s.