Question

The number of oscillations or vibrations made by a vibrating body in one second is known as the frequency of the wave. The SI unit of frequency is $hertz\left(Hz\right)$which is named after the name of scientist Heinrich Hertz. Time taken to complete one vibration by the vibrating body is known as the time period. Time period and frequency are related as

$Timeperiod=\frac{1}{frequency}$

The frequency of sound is $20Hz$. Find its time period.

• A. 0.05 s.
• B. 0.5 s.
• C. 0.2 s.
• D. 0.02 s.

Answer 1

The correct option is A

0.05 s.

Step 1: Given data

Frequency of sound, $f=20Hz$

Time period, $T=?$

Step 2: Formula used

The time period in terms of the frequency of the wave is,

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

Step 3: Calculation of the time period

Substituting the given value of frequency in the above equation,

$$\begin{gathered} T=\frac{1}{20Hz} \\ T=0.05s \end{gathered}$$

Hence, option (A) is correct.