suresh kumar
Last Activity: 4 Years ago
the example of cylindrical source is the line of light. it emits cylindrical expanding wave fronts.
intensity
I=P/area ,
P is the power of source which is constant
Hence I∝1/area
area of cylinder ,
a=2πrh , (h=height of cylinder) ,
therefore intensity of wave ,
I∝1/2πrh ,
which implies I∝1/r
we have , I∝A2 (A= amplitude)
we get , A2 ∝1/r ,
A∝1/sqt(r)
Hence, last option is correct
