Answer:
Explanation:
a )
Frequency n = 450 x 10⁶ .
20 light years = 20 x 9.461 x 10¹⁵m
Let power of source be P
Intensity at distance R = [tex]\frac{P}{4\pi R^2}[/tex]
Substituting the given values
8.5 x 10⁻¹⁰ = [tex]\frac{P}{4\pi ((20\times9.461\times10^{15})^2}[/tex]
P = 3822457 x 10²⁰ W.
b )
Half the power will be from electric and half will be from magnetic field.
Total power = 8.5 x 10⁻¹⁰ W
Half = 4.25 x 10⁻¹⁰ W .
power of electric field
= [tex]\frac{1}{2}\epsilon\times E_0^2\times c[/tex]
ε is permittivity , E₀ is amplitude of electric field , c is velocity of light .
Putting the values
4.25 x 10⁻¹⁰ = .5 x 8.85 x 10⁻¹² x E² x 3 x 10⁸
E₀² = .32 x 10⁻⁶
E₀ = .565 x 10⁻³ W / s .
