Name one musical instrument each in which the sound is produced:

(a) by vibrating a stretched string.

(b) by vibrating air enclosed in a tube.

(c) by vibrating a stretched membrane

(d) by vibrating metal plates.

Explain why, the flash of lightning is seen first but the sound of thunder is heard a little later (though lightning and thunder take place in the sky at the same time and same distance from us).

Name the object (or part) which vibrates to produce sound in the following musical instruments :

(a) Sitar

(b) Dholak

(c) Flute

(d)Cymbals

(e) Veena

(f) Tabla

Give two examples of each of the following :

(a) stringed musical instruments.

(b) wind musical instruments.

(c) membrane musical instruments.

(d) plate type musical instruments.

Which of the sounds having the following frequencies can be heard by the human beings and which cannot?

(a) 6 hertz

(b) 5000 hertz

(c) 10000 hertz

(d) 35000 hertz

(e) 18kHz