Question

The time period of a sound wave from a piano is $1.18\times {10}^{-3}s$. Find its frequency.

• A. $847.45Hz$
• B. $800Hz$
• C. $935.55Hz$
• D. $1000Hz$

Answer 1

Answer: (A)

$847.45Hz$

The frequency (f) of a wave is the number of full waveforms generated per second. This is the same as the number of repetitions per second or the number of oscillations per second.
Time Period (T) is the number of seconds taken to cover one wavelength or the number of seconds per oscillation. It is clear that frequency and period are reciprocals.
In this case, the time period is given as $1.18\times {10}^{-3}s$.
So, the frequency $f=\frac{1}{T}=\frac{1}{0.00118s}=847.45Hz.$