Home
Class 11
PHYSICS
A point source of sound emits a constant...

A point source of sound emits a constant power with intensity inversely proportinal to the square of the distance from the source . By how many decible does the sound intensity level drops when you move from point `P_(1)` to `P_(2)` ? Distance of `P_(2)` from the source is two times the distance of source from `P_(1)` .

Text Solution

Verified by Experts

The correct Answer is:
A, B, D
we label the two points `1` and `2`, and we use the equation `beta = 10`log `(I)/(I_(0)) (dB)` twice. The difference in sound intensity level `beta_(2) -beta _(1)` is given by
`beta_(2) -beta_(1) = (10 dB)(log .I_(2)/(I_(0))- log .I_(1)/(I_(0)))`
`(10dB)[(log I_(2)-log I_(0)) - (log I_(1) - log I_(0))]`
`= (10 dB) log .I_(2)/(I_(1))`
Now, `Iprop (1)/(r^(2))rArr :. (I_(2))/(I_(1))= ((r_(1))/(r_(2)))^(2)= (1)/(4) as r_(2) = 2r_(1)`
:. `beta_(2)- beta_(1) = (10 dB) log ((1)/(4)) = - 6.0 dB`
Promotional Banner

Topper's Solved these Questions

  • SOUND WAVES

    DC PANDEY ENGLISH|Exercise Example Type 1|4 Videos

  • SOUND WAVES

    DC PANDEY ENGLISH|Exercise Example Type 2|2 Videos

  • SOLVD PAPERS 2017 NEET, AIIMS & JIPMER

    DC PANDEY ENGLISH|Exercise Solved paper 2018(JIPMER)|38 Videos

  • SUPERPOSITION OF WAVES

    DC PANDEY ENGLISH|Exercise Level 2 Subjective|8 Videos

Similar Questions

Explore conceptually related problems

An isotropic point source 'S' of sound emits constant power. Two points A and B are situated at distance x and 2x from S. the difference between the loudness of points A and B is about (log 2=0.3)

A point P is such that the sum of the squares of its distances from the two axes of co-ordinates is equal to the square of its distance from the line x-y=1 . Find the equation of the locus of P.

The intensity of sound from a point source is 1.0 xx 10^-8 Wm^-2 , at a distance of 5.0 m from the source. What will be the intensity at a distance of 25 m from the source ?

A point source emits sound waves with an average power output of 80.0 W (a) Find the intensity 3.00 m from the source. (b) find the distance at which the intensity of the sound is 1.00xx10^-8(W)/(m^2)

A point source of sound is placed in a non-absorbing medium two points A and B are at the distance of 1 m and 2 m, respectively, from the source. The ratio of amplitudes of waves at A to B is

A point source of sound is placed in a non-absorbing medium two points A and B are at the distance of 1 m and 2 m, respectively, from the source. The ratio of amplitudes of waves at A to B is

The intensity produced by a long cylindrical light source at a small distance r from the source is proportional to

A point source emits sound equally in all directions in a non-absorbing medium. Two point P and Q are at distance of 2 m and 3 m respectively from the source. The ratio of the intensities of the wave at P and Q is :

The intensity of a point source emitting sound at distance 3 from the source is 0.707 W//m^2? What is the average power output of the source ?

A line source of sound of length 10 m, emitting a pulse of sound that travels radially outward from the source. The power of the source is P = 1.0.x 10^4 W What is the approximated intensity '/' of the sound when it reaches a distance of 10 m from the source?