A point source of electromagnetic radiation has average power output of 800 watt, then find
(a) Maximum value of electric field at a distance 3.5 m from the source
(b) Maximum value of magnetic field
(c) Average energy density at 3.5 m from the source.

Explanation

`l=(P)/(4pir^(2))=(800)/(4xx3.14xx(3.5)^(2))`
`l=5.2("watt")/(m^(2))`
`(a)l=(1)/(2)epsi_(0)E_(0)^(2(xxc`
`E_(0)=sqrt((2xxl)/(epsi_(0)xxc))=sqrt((5.2xx)/(8.85xx10^(-12)xx3xx10^(8)))=0.626xx10^(2)=62.6(N)/(C)`
(b) `B_(0)=(E_(0))/(c)=(62.6)/(3xx10^(8))=20.87xx10^(-7)xxT`
(c) `U=(1)/(2)epsi_(0)E_(0)^(2)=(8.85xx10^(-12))/(2)xx(62.6)^(2)=1.74xx10^(-8)(J)/(m^(-3))`