Describe an experiment to show the production of sound having low and high pitch.

The following experiment shows the production of sound having low and high pitch.

1. Take four test tubes. In first test tube take a little amount of water in it.
2. Blow air in the tube by placing your lip on the mouth of the test tube.

You will hear a flat sound i.e. sound of low pitch.

3. Now add more and more water in the remaining three test tubes as shown in below figure.
4. Again blow air in each of these three test tubes.

You will notice sound becomes more and more shrill i.e. high pitch.

In first tube water is very less, so flat sound (low pitch) is produced. As we add more and more water in the tubes, the length of vibrating air column above water level decreases, so sound becomes more shriller (high pitch).