The correct answer of the question is : 0.001 s.
CALCULATION:
As per the question, the speed of sound v = 330 m/s
The frequency of the sound f = 990 Hz.
Let the wavelength of the wave is [tex]\lambda[/tex].
The wavelength of the wave is calculated as-
wavelength [tex]\lambda=\frac{speed}{frequency}[/tex]
= [tex]\frac{330}{990}\ m[/tex]
= 0.33 m.
Now we are asked to calculate the time period.
The time period of the wave is reciprocal of frequency.
Mathematically time period T = [tex]\frac{1}{f}[/tex]
= [tex]\frac{1}{990}\ s[/tex]
= 0.001 s.
As per the question, we need the period.
Hence, the period of the wave is 0.001 s.
