Answer:
a)Frequency= Â 7.9 x 10 ^7Hz
b)Rms value of electric field=22.065 V/m
c) Intensity of light =1.291W/m²
Explanation:
a) Frequency of wave
first, The Angular wave number k is calculated as 2π/λ( wavelength)
and Wave number = 1.66 m -1
Wavelength = Â 2Ï€/k
     = 2(3.142) /1.66
      =3.786m
              Â
Therefore Frequency f = c/λ
       =3 x10^8 /3.786
         = 79,239,303Hz = 7.9 x 10 ^7Hz
b) The RMS of electric component
First, we find The amplitude of the  electric field,  E = c B Â
where the  Amplitude of the magnetic field, B  =  104nT =104 x10 -9 T
  = 3 x10^8 x 104 x10 -9 )
=31.2V/m
Rms value of electric field E rms = E /[tex]\sqrt2[/tex]
   = 31.2 / 1.414
   = 22.065 V/m
C) Intensity of light = (E rms)² / μ₀c
μ₀=magnetic permeability of free space, 4π x 10^-7N/A²
c= speed of light = 3x 10^8m/s
=(22.065)²/ 4π x 10^-7 x 3x 10^8m/s
=1.291W/m²
