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NEET-XII-Physics

08: Electromagnetic Waves

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  • #8
    Suppose that the electric field amplitude of an electromagnetic wave is E0 = 120 N/C and that its frequency is ν = 50.0 MHz. (a) Determine, B0, ω, k, and λ. (b) Find expressions for E and B.
    Ans : Electric field amplitude, E0 = 120 N/C

    Frequency of source, ν = 50.0 MHz = 50 × 106 Hz

    Speed of light, c = 3 × 108 m/s
    (a) Magnitude of magnetic field strength is given as:



    Angular frequency of source is given as:

    ω = 2``\pi``ν

    = 2``\pi`` × 50 × 106

    = 3.14 × 108 rad/s

    Propagation constant is given as:



    Wavelength of wave is given as:


    (b) Suppose the wave is propagating in the positive x direction. Then, the electric field vector will be in the positive y direction and the magnetic field vector will be in the positive z direction. This is because all three vectors are mutually perpendicular.

    Equation of electric field vector is given as:



    And, magnetic field vector is given as:


  • #8-a
    Determine, B0, ω, k, and λ.
    Ans : Magnitude of magnetic field strength is given as:



    Angular frequency of source is given as:

    ω = 2``\pi``ν

    = 2``\pi`` × 50 × 106

    = 3.14 × 108 rad/s

    Propagation constant is given as:



    Wavelength of wave is given as:


  • #8-b
    Find expressions for E and B.
    Ans : Suppose the wave is propagating in the positive x direction. Then, the electric field vector will be in the positive y direction and the magnetic field vector will be in the positive z direction. This is because all three vectors are mutually perpendicular.

    Equation of electric field vector is given as:



    And, magnetic field vector is given as: