A point source emits sound equally in all dir | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) For a point source emitting sound in all directions,the intensity $I$ at a distance $r$ is given by $I = \frac{P}{4\pi r^2}$,where $P$ is the powe

Vedclass · Accepted Answer

$25:9$

Vedclass · Answer

(C) For a point source emitting sound in all directions,the intensity $I$ at a distance $r$ is given by $I = \frac{P}{4\pi r^2}$,where $P$ is the power of the source. Thus,$I \propto \frac{1}{r^2}$.Since the intensity $I$ is proportional to the square of the amplitude $A$ $(I \propto A^2)$,we have $A^2 \propto \frac{1}{r^2}$,which implies $A \propto \frac{1}{r}$.Therefore,the ratio of the amplitudes at points $P$ and $Q$ is $\frac{A_P}{A_Q} = \frac{r_Q}{r_P}$.Given $r_P = 9 \ m$ and $r_Q = 25 \ m$,the ratio is $\frac{A_P}{A_Q} = \frac{25}{9}$.

$A$ point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$ are at a distance of $9 \ m$ and $25 \ m$ respectively from the source. The ratio of the amplitudes of the waves at $P$ and $Q$ is

Similar Questions

Which property distinguishes progressive waves from stationary waves?

The intensity of sound after passing through a slab decreases by $30\%$. On passing through two such slabs,the intensity will decrease by ..... $\%$

$A$ wave can transmit ...... from one place to another.

$A$ person speaking normally produces a sound intensity of $40 \ dB$ at a distance of $1 \ m$. If the threshold intensity for reasonable audibility is $20 \ dB$,the maximum distance at which he can be heard clearly is ... $m$.

$A$ string of mass $100 \, g$ is clamped between two rigid supports. $A$ wave of amplitude $2 \, mm$ is generated in the string. If the angular frequency of the wave is $5000 \, rad/s$,then the total energy of the wave in the string is ..... $J$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module