How do you calculate frequency of a wave?

Hint: To solve this question first we have to understand the term frequency. Frequency is defined as the number of occurrences of a repeating event per unit time.

Complete step by step answer:
- Frequency is defined as the number of repeating events per unit time. If we talk about a wave it is the number of waves occurring per unit time. The unit of frequency is hertz. One hertz is equal to the one occurrence of a repeating unit or a wave per unit second. Hertz is represented as capital H followed by a small z i.e. Hz.
- The formula to calculate frequency of a wave is mentioned below:
\[f=\dfrac{c}{\lambda }\]
Where, c is the speed of light and,
$\lambda $ is the wavelength .

Additional Information :We can calculate frequency, wavelength and wavenumber if only one of the quantities is mentioned. Wavelength is the distance between the identical points in the adjacent cycles of the wave signals. And the wave number can be defined as the spatial frequency of a wave which is measured in cycles per unit distance or sometimes in radian per unit distance.

Note: The energy which is carried out by a single photon i.e. the packet of light. Is directly proportional to the photons electromagnetic frequency and this means that it is inversely proportional to the wavelength. Do not confuse the terms wavelength and wave number and please take the case of the units while solving numerical problems related to the frequency.