Sound

Question 1

State the relation between velocity frequency and wavelength

Answer 1

V=fλ

Question 2

Define echo

Answer 2

The sound heard after reflection from a distant obstacle after the original sound has seed

Question 3

Conditions for an echo

Answer 3

The minimum distance between the source of the sound and the selector in the air must be 17 m the size of the reflector must be large enough as compared to the wavelength of the sound the intensity of the sound should be sufficient

Question 4

State the safe limit of sound level in terms of decibel for human earing

Answer 4

30 DB to 10db

Question 5

Define noise pollution

Answer 5

Undesirable loud and Harsh sound of level above 120 DB which causes headache is called noise pollution

Question 6

Define loudness

Answer 6

Loudness is a characteristic of sound which helps distinguish between loud and faint sound of the same pitch and quality

Question 7

Define natural vibration and give its example

Answer 7

The periodic vibrations of a body in the absence of any external force on it is called natural vibration example the bob of a simple pendulum load suspended from a spring

Question 8

State the relation between the frequency and tension

Answer 8

F = /T

Question 9

State the relation between frequency and length

Answer 9

F = 1/L

Question 10

State the relation between frequency and amplitude

Answer 10

F = a²

Question 11

Define damped vibration and give its example

Answer 11

Periodic vibrations of a body of decreasing amplitude in the presence of resistive force are called damped vibration example slim branch of a tree spoiled tuning 4 coins proved on a rubber band simple pendulum oscillating in air

Question 12

Define forced vibration and give its example

Answer 12

Vibration of a body which take place under an influence of an external periodic force acting on it is called flues vibration example guitar stem of A vibrating tuning for best against the top of a table

Question 13

Define resonance

Answer 13

Resonance is a special case of forced vibration when the frequency of the externally applied periodic force on a body is equal to its natural frequency a body readily begins to vibrate with an increased amplitude

Question 14

State the conditions for resonance

Answer 14

Resonance occurs only when the plied force causes first vibration in the body and the frequency of the applied force is exactly equal to the natural frequency of the vibrating body