Home
Class 12
PHYSICS
In a plance electromagnetic wave, the el...

In a plance electromagnetic wave, the electric field oscillates with a frequency `2xx10^(10) s^(-1)` and amplitude `40 Vm^(-1)`, then the energy density due to electric field is `(epsilon_(0)=8.85xx10^(-12)Fm^(-1))`

A

`1.52xx10^(9)" Jm"^(-3)`

B

`2.54xx10^(9)" Jm"^(-3)`

C

`3.54xx10^(9)" Jm"^(-3)`

D

`4.56xx10^(9)" Jm"^(-3)`

Text Solution

Verified by Experts

The correct Answer is:
C
Energy density due to electric field is
`U=(1)/(2) epsi_(0) E^(2)`
Here, `E=(E_(0))/(sqrt(2))=(40)/(sqrt(2))`
`therefore" "U=(1)/(2)xx8.85xx10^(-12) xx (40xx40)/(2)`
`=3.54xx10^(-9) J//m^(3)`
Promotional Banner

Similar Questions

Explore conceptually related problems

In a plane electromagnetic wave, the electric field oscillates sinusoidally at a frequency of 2.0xx10^(10) Hz and amplitude 48 V m^(-1) .

In a plane electromagnetic wave, the electric field oscillates sinusoidally at a frequency of 2.0xx10^(10) Hz and amplitude 48 V m^(-1) . What is the wavelength of the wave ?

A wave has a frequency of 3 xx 10^(15) sec^(-1) . The energy of that photon is

An electromagnetic wave having frequency 4 xx 10^(14)Hz is passing through a small volume. The energy contained in this volume oscillates with frequency.

The magnetic field in a plane electromagnetic wave is given by B_(y)=2xx10^(-7)sin (0.5xx10^(3)x + 1.5 xx 10^(11) t)T . Write an expression for the electric field.