A disturbance is the cause of a wave it may be a simple pulse or shock like the clapping of hands. It may also be periodic in nature that is, repeated again and again at regular intervals. A vibrating guitar string produces continuous periodic waves. Some of the wave characteristics are used to explain the periodic wave motion.
The oscillations of a wave may be characterized in terms of frequency. |

The wave frequency (f) is the number of oscillations or cycles that
occur during a given period of time usually a second. That is frequency
is the number of cycles per second, but this unit gives the name
hertz(Hz). One hertz is one cycle per second. The frequency and period
are inversely proportional.

As mentioned earlier, frequency and period are inter related quantity. So we can formulate the equation for frequency in terms of period. Frequency is denoted as f and period is denoted as T. Expressing this in equation form,

Frequency = $\frac{1}{Period}$

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

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

Radio waves are nothing but the electromagnetic radiation which produces the radio wave spectrum. The frequency is range is from 30 kHz to 300 GHz. It has lowest frequency among the waves in electromagnetic spectrum. These waves are used in antennas and they are used in transmission purposes etc.

In the case of sound waves, it propagates through a medium with definite velocity. This velocity depends on the nature of the medium. According to frequency, the important category under sound waves are high frequency and low frequency sound waves. High frequency wave means the number of vibration per second is more compared to that of low frequency wave.

Sine wave is nothing but the representation of mathematical curve with periodic oscillation. The expression for sine wave is given by,

where,

$\omega$ = 2$\pi$ f

Some solved problems related to the frequency of wave mentioned in this section.**y = A sin($\omega$ t+$\phi$ )**

where,

*is the amplitude of the wave***A***is the angular frequency***$\omega$**$\omega$ = 2$\pi$ f

*is the frequency of wave***f***is the phase of the wave***$\phi$**### Solved Examples

**Question 1:**Calculate the frequency of a wave whose period is given by 0.1s?

**Solution:**

From the question it is clear that,

T = 0.1s

The equation for wave frequency is,

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

f = $\frac{1}{0.1}$ = 10 Hz

**Question 2:**If the period of a wave is 0.025s, calculate its frequency?

**Solution:**

From the question it is clear that,

T=0.025s

The equation for wave frequency is,

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

f=$\frac{1}{0.025}$=40 Hz