A point source is kept at the center of a sph | vedclass

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

Question

(D) The volume of a sphere is given by $V = \frac{4}{3} \pi R^3$,which implies $V \propto R^3$.If the volume $V$ increases by $8$ times,then $R^3$ inc

Vedclass · Accepted Answer

decrease by $4$ times

Vedclass · Answer

(D) The volume of a sphere is given by $V = \frac{4}{3} \pi R^3$,which implies $V \propto R^3$.If the volume $V$ increases by $8$ times,then $R^3$ increases by $8$ times,so the radius $R$ increases by $2$ times $(R \rightarrow 2R)$.The surface area of the sphere is $A = 4 \pi R^2$,which implies $A \propto R^2$.Since $R$ increases by $2$ times,the area $A$ increases by $2^2 = 4$ times $(A \rightarrow 4A)$.Intensity $I$ is defined as power per unit area,$I = \frac{P}{A}$.Since the power $P$ of the point source remains constant,$I \propto \frac{1}{A}$.Therefore,if the area $A$ increases by $4$ times,the intensity $I$ will decrease by $4$ times $(I \rightarrow \frac{I}{4})$.

$A$ point source is kept at the center of a spherically enclosed detector. If the volume of the detector is increased by $8$ times,the intensity will

Similar Questions

With the propagation of a longitudinal wave through a material medium,the quantities transmitted in the propagation direction are

The intensity of sound from a radio at a distance of $2 \ m$ from its speaker is $1 \times 10^{-2} \ \mu W/m^2$. The intensity at a distance of $10 \ m$ would be:

The intensity ratio of two waves is $1 : 16$. The ratio of their amplitudes is

The ratio of intensities of two waves is given by $4:1$. The ratio of the amplitudes of the two waves is

The intensity of a sound wave while passing through an elastic medium falls by $10\%$ as it covers $1 \ m$ distance through the medium. If the initial intensity of the sound wave was $100 \ dB$,its value after it has passed through $3 \ m$ thickness of the medium will be .... $dB$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module