At the upper surface of the earth's atmosphere, the time-averaged magnitude of the Poynting vector is referred to as the solar constant and is given by =1.35×103W⋅m−2 .

Question

At the upper surface of the earth's atmosphere, the time-averaged magnitude of the Poynting vector is referred to as the solar constant and is given by =1.35×103W⋅m−2 . (a) If you assume that the sun's electromagnetic radiation is a plane sinusoidal wave, what is the magnitude of the electric field in V/m? (b)What is the magnitude of the magnetic field in T? (c) What is the time-averaged power (in Watt) radiated by the sun? The mean sun-earth distance is res=1.50×1011m

Elena · Accepted Answer

(a) The time-averaged Poynting vector is =cε₀E₀²/2. The amplitude of electric field is E=sqrt{2/ cε₀} = =sqrt{2•1.35•10³/3•10⁸•8.85•10⁻¹²} = 1.01•10³ V/m. (b) The magnetic field is B₀=E₀/c =1.01•10³/3•10⁸ =3.4•10⁻⁶ T. (c) The time-averaged power radiated by the Sun at distance R is
=~~A = ~~4πR² = =1.35•10³•4π•(1.5•10¹¹)²=3.8•10²⁶W~~~~

Rohan · Answer

thnx Elena :)

At the upper surface of the earth's atmosphere, the time-averaged magnitude of the Poynting vector is referred to as the solar constant and is given by </S/>=1.35×103W⋅m−2 .