Question

A tuning fork’s vibrate 250 times in 2.0s. Find the frequency of vibration.
A. 125Hz
B. 200Hz
C. 250Hz
D. 600Hz

Answer 1

Hint: Frequency is the representation of the number of cycles covered by a wave up unit time required to achieve those cycles. Commonly these cycles are also termed as vibration. The SI unit of frequency is hertz denoted as "Hz”.

As per the given data,
No of vibration = 250
Time duration in which 250 vibrations occurs = 2s

Formula to be used:
$f=\dfrac{vibrations}{time}$

Complete answer:
The cycles of any wave are termed as oscillation and oscillations performed per unit time is known as frequency. It shows how often an event can take place. Many factors of a wave are dependent on frequency. One of the dependent functions is the speed of any wave.
The frequency is dependent on the no of cycle repetition performed by the wave per the time required for these repetitions.
$f=\dfrac{vibrations}{time}$
By putting the values of no of vibrations and time
$\begin{align}
  & f=\dfrac{250}{2} \\
 & \Rightarrow f=125Hz \\
\end{align}$

So, the correct option is option A.

Additional information:
The frequency and wavelength of a wave are inversely proportional to each other. Greater will be the wavelength lower will be the frequency of the wave. $\lambda \propto \dfrac{1}{f}$
The greater the frequency of a wave higher will be the speed of the propagation of the wave. $f=\dfrac{c}{\lambda }$

Note:
A period is a time the wave takes to do a particular work. Both the frequency and period are different concepts. The period depends on frequency but both are different. The period of a wave is measured in the unit of time.