1. Frequency of the electromagnetic wave,ν = 2.0 x 1010 Hz Electric field amplitude, Eo = 48 V m⁻¹ Speed of light, c = 3 x 108 m/s Ans (a). Wavelength of a wave is given by : λ = c/ν  =  (3 x 108) /(2.0 x 1010) = 0.015 m Ans (b). Magnetic field strength is given by: B0= E0/c = 48 /(3 x 108)= 1.6 x 10⁻⁷Read more

    Frequency of the electromagnetic wave,ν = 2.0 x 1010 Hz

    Electric field amplitude, Eo = 48 V m⁻¹

    Speed of light, c = 3 x 108 m/s

    Ans (a).

    Wavelength of a wave is given by :

    λ = c/ν 

    =  (3 x 108) /(2.0 x 1010) = 0.015 m

    Ans (b).

    Magnetic field strength is given by:

    B0= E0/c = 48 /(3 x 108)= 1.6 x 10⁻⁷ T

    Ans (c).

    Energy density of the electric field is given by :

    UE = 1/2 ε0

    And, energy density of the magnetic field is given as:

    UB = 1/2 μ0

    Where,

    ε0 = Permittivity of free space

    μ0 = Permeability of free space We have the relation connecting E and B as:

    E = cB———————–Eq-1

    Where,

    c = 1/√(ε0μ0)————-Eq-2

    Putting equation (2) in equation (1), we get

    E = [1/√(ε0μ0)]B

    Squaring both sides, we get

    E² = [1/(ε0μ0)]B²

    =>  E²ε0 = B²/μ0

    =>1/2 x E²ε0 = 1/2 x B²/μ0

    => UE = UB

     

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  2. Energy of a photon is given as: E = hν = hc/λ  Where, h = Planck’s constant = 6.6 x 10-34 Js c = Speed of light = 3 x 1o8 m/s λ = Wavelength of radiation Therefore, E = (  6.6 x 10-34 x 3 x 1o8) /λ = (19.8 x 10⁻²⁶ )/λ J =  (19.8 x 10⁻²⁶ )/( λ x 1.6 x 10⁻¹⁹)    = (12.375x10⁻7 )/λ eV The given table lRead more

    Energy of a photon is given as:

    E = hν = hc/λ 

    Where,

    h = Planck’s constant = 6.6 x 10-34 Js

    c = Speed of light = 3 x 1o8 m/s

    λ = Wavelength of radiation

    Therefore,

    E = (  6.6 x 10-34 x 3 x 1o8) /λ

    = (19.8 x 10⁻²⁶ )/λ J

    =  (19.8 x 10⁻²⁶ )/( λ x 1.6 x 10⁻¹⁹)

       = (12.375×10⁻7 )/λ eV

    The given table lists the photon energies for different parts of an electromagnetic spectrum for different λ are:

    λ(m) 10³ 1 10⁻³ 10⁻⁶ 10⁻⁸ 10⁻¹⁰ 10⁻¹²
    E (eV) 12.375 x 10⁻¹⁰ 12.375 x 10⁻⁷ 12.375 x 10⁻⁴ 12.375 x 10⁻¹ 12.375 x 10¹ 12.375 x 10³ 12.375 x 10⁵

    The photon energies for the different parts of the spectrum of a source indicate the spacing of the relevant energy levels of the source.

     

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  3. Electric field amplitude, Eo = 120 N/C Frequency of source, ν = 50.0 MHz = 50 x 106 Hz Speed of light, c = 3 x 108m/s Ans (a). Magnitude of magnetic field strength is given as: B0 =E0 /c = 120/(3 x 108) = 4 x 10⁻7 T= 400 nT Angular frequency of source is given as: ω =2πν = 2π x 50 x 106 = 3.14 x 108Read more

    Electric field amplitude, Eo = 120 N/C

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

    Speed of light, c = 3 x 108m/s

    Ans (a).

    Magnitude of magnetic field strength is given as:

    B0 =E0 /c

    = 120/(3 x 108)

    = 4 x 10⁻7 T= 400 nT

    Angular frequency of source is given as:

    ω =2πν = 2π x 50 x 106 = 3.14 x 108 rad/s

    Propagation constant is given as:

    k = ω/c   = (3.14 x 108 )/(3 x 108) =6.0 m

    Ans (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:

    E = E0 sin (kx-ωt)j 

    = 120 sin [ 1.05 x -3.14 x 10⁸ t] j

    And, Magnetic field vector is given as :

    B = B0 sin (kx-ωt)k

    = (4 x 10 sin⁻⁷ )[ 1.05 x -3.14 x 10⁸ t] k

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  4. Amplitude of magnetic field of an electromagnetic wave in a vacuum, Bo = 510 nT = 510 x 10⁻9T Speed of light in a vacuum, c = 3 x 108 m/s Amplitude of electric field of the electromagnetic wave is given by the relation, E = cBo = 3 x 108x 510 x 10⁻9= 153 N/C Therefore, the electric field part of theRead more

    Amplitude of magnetic field of an electromagnetic wave in a vacuum,
    Bo = 510 nT = 510 x 10⁻9T
    Speed of light in a vacuum, c = 3 x 108 m/s
    Amplitude of electric field of the electromagnetic wave is given by the relation,
    E = cBo
    = 3 x 108x 510 x 10⁻9= 153 N/C

    Therefore, the electric field part of the wave is 153 N/C.

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  5. The frequency of an electromagnetic wave produced by the oscillator is the same as that of a charged particle oscillating about its mean position i.e., 109 Hz.

    The frequency of an electromagnetic wave produced by the oscillator is the same as that of a charged particle oscillating about its mean position i.e., 109 Hz.

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