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A plane EM wave travelling along z direc...

A plane EM wave travelling along z direction is described by
`E=E_0sin (kz-omegat) hati and B=B_0 sin (kz-omegat)hatj`.
show that
(i) The average energy density of the wave is given by `u_(av)=1/4 epsilon_0 E_0^2+1/4 (B_0^2)/(mu_0)`.
(ii) The time averaged intensity of the wave is given by `I_(av)=1/2 cepsilon_0E_0^2`.

Text Solution

AI Generated Solution

To solve the problem, we need to find the average energy density and the time-averaged intensity of a plane electromagnetic wave described by the electric field \( E = E_0 \sin(kz - \omega t) \hat{i} \) and the magnetic field \( B = B_0 \sin(kz - \omega t) \hat{j} \). ### Part (i): Average Energy Density 1. **Energy Density in Electric Field**: The energy density \( u_E \) in the electric field is given by: \[ u_E = \frac{1}{2} \epsilon_0 E^2 ...
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Knowledge Check

  • An electromagnetic wave travelling along z-axis is given as E=E_(0) " cos "(kz- omegat). Choose the correct options from the following

    A
    The associated magnetic field is given as `vec(B)=(1)/(c)hat(k) xx vec(E)=(1)/(omega)(vec(k)xxvec(E))`
    B
    The electromagnetic field can be written in terms of the associated magnetic field as `vec(E)=c(vec(B)xxhat(j))`
    C
    `hat(k).vec(E)=0,hat(k).vec(B)ne0`
    D
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  • The electric field of an electromagnetic wave travelling through vacuum is given by the equation E = E_(0) "sin"(kx - omegat) The quantity that is independent of wavelength is

    A
    `komega`
    B
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    D
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