Q1.
Explore various ways of producing sound.
Answer
Every method comes down to one thing — making something vibrate. The ways differ only in what is set vibrating.
| Way of producing sound | What vibrates | Everyday example |
|---|---|---|
| Plucking | A stretched string | Sitar, veena, guitar, ektara, rubber band |
| Striking / hitting | A stretched membrane or a metal body | Tabla, dholak, taal (manjira), temple bell, tuning fork |
| Blowing | The air column inside a pipe | Bansuri, shehnai, conch (shankh), whistle |
| Bowing | A string, rubbed by a bow | Sarangi, violin |
| Rubbing / scraping | The two rubbing surfaces | Crickets and grasshoppers rubbing wings or legs; chalk squeaking on a board |
| Forcing air past flaps | Vocal cords | Speaking, singing, animal calls |
| Sudden expansion of hot gas | The air itself | Firecracker, thunder, bursting balloon, sonic boom |
| Electrical signal driving a cone | Speaker diaphragm | Mobile phone, radio, loudspeaker |
The common thread: in every row, some object is made to move to and fro. That motion squeezes and stretches the neighbouring air, and the resulting density disturbance is what we call sound.