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A flood light is covered with a fitter t...

A flood light is covered with a fitter than transmits red light. The electric field of the emerging beam is represented a sinusolidal plane wave
`E_(x)=36 sin (1.20xx10^(7)z-3.6xx10^(15)t) V//m`
The average intensity of beam is `"watt"//("metre")^(2)` will be

A

`0.86 W//m^(2)`

B

`1.72 W//m^(2)`

C

`3.44 W//m^(2)`

D

`6.88 W//m^(2)`

Text Solution

Verified by Experts

The correct Answer is:
B
`I_(av)=(cepsilon_(0)E_(0)^(2))/(2)=(3xx10^(8)xx8.85xx10^(-12)xx36^(2))/(2)=1.72W/m^(2)`
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