CBSE Class 8 Answered

(a) We can demonstrate the working of vocal to produce sound as follows: Take two rubber strips of the same size. Place these two rubber strips one above the other. Hold the two ends of the rubber strips in your hands and stretch them tight. Keep the stretched rubber strips in front of your mouth and blow air through the thin gap between them (see figure).

As the air blows through the stretched rubber strips, a sound is produced. This sound is produced by the vibrations of stretched rubber strips when air rushes through the thin gap between them. Our vocal cords produce sound in a similar way.