Fill in the blanks with suitable words.

a) The to and fro motion of a body from its mean position is called …………………..

b) Number of vibrations per second is called …………………..

c) The intensity of sound can be measured in ………………….

d) Sound cannot travel in ………………….

e) Vibrating bodies produce ……………………

f) The maximum displacement of a body from its mean position is called …………..

(a) The to and fro motion of a body from its mean position is called One Vibration.

Explanation: Vibration is the disturbance created by some source for example human activity, due to which an object gets displaced forwards and backwards with respect to its initial position. A real life example of it is the vibration of a guitar string.

(b) Number of vibrations per second is called Frequency

Explanation: Frequency is nothing but the number of times an event is repeated in one second.

(c) The intensity of sound can be measured in dB (decibels).

Explanation: Decibels is the unit in which the numeric evaluation of sound is performed.

(d) Sound cannot travel in vacuum.

Explanation: Propagation of sound always requires a material medium and since in vacuum there is no material medium, sound cannot travel in vacuum.

(e) Vibrating bodies produce sound.

Explanation: For the production of sound a vibrating source is a must. For example, while playing guitar, the musical sound is produced due to the vibration of different strings.

(f) The maximum displacement of a body from its mean position is called amplitude.

Explanation: Amplitude is nothing but the farthest distance between an object’s mean position and the displaced position.