Answer
given,
Area = 0.7 m²
electric field of wave = 0.0400 V/m
time = t =30 s
intensity of electromagnetic wave
[tex]I = \dfrac{E_0^2}{2\mu_0c}[/tex]
[tex]E_0^2 = 2 E_{rms}^2[/tex]
c is speed of light
[tex]I = \dfrac{2E_{rms}^2}{2\mu_0c}[/tex]
[tex]I = \dfrac{E_{rms}^2}{\mu_0c}[/tex]
[tex]I = \dfrac{0.04^2}{4\pi \times 10^{-7}\times 3 \times 10^8}[/tex]
I = 4.24 x 10⁻⁶ W/m²
the amount of energy required
E = I A t
E = 4.24 x 10⁻⁶ x 0.7 x 30
E = 8.9 x 10⁻⁵ J
