Question

Chapter - 13 Sound
I. FILL IN THE BLANKS
or the
1. To and fro or back and forth motion of an object is called
2. In humans, the sound is produced by the
2. are stretched across the voice box or larynx.
4. The vocal cords in men are about mm long.
5. The determines the shrillness or pitch of a sound.
6. Noise becomes physically painful at dB.
7.
on the roadside and elsewhere can reduce noise pollution.
8.
and are the two important properties of sound.
9.
senses the vibration of sound.
10. The loudness of sound depends on its
No

Answer 1

Answer:

1. ans=vibration and oscillation

2.ans=

Answer 2

Answer:

(1)- Oscillatory motion

(2)-The vibrating vocal cords

(3)- Two vocal cords

(4)-About 20mm

(5)-The frequency

(6)- Above 80db

(7)-Plantation

(8)- Speed,Loudness and pitch

(9)- Hearing

(10)-Amplitude