Why a sound produced when fingers are place over the guitar strings?

When fingers are placed over the guitar strings, it changes the effective length of the string. This, in turn, changes the frequency of the sound produced by the string. The higher the finger is placed on the string, the shorter the effective length of the string and the higher the frequency of the sound produced.

The exact frequency of a sound produced by a guitar string can be calculated using the following equation:

```

f = (1/2L)√(T/m)

```

where:

* f is the frequency of the sound in Hz

* L is the length of the string in meters

* T is the tension in the string in Newtons

* m is the mass of the string in kilograms

As you can see from the equation, the frequency of a sound is inversely proportional to the length of the string. This means that the shorter the string, the higher the frequency of the sound produced.

When you place your finger on a guitar string, you are effectively shortening the length of the string. This causes the frequency of the sound produced by the string to increase. The higher the finger is placed on the string, the shorter the effective length of the string and the higher the frequency of the sound produced.

This is why different notes are produced when different fingers are placed over the guitar strings. The higher the finger is placed on the string, the higher the note produced.