Question

The electric field in an electromagnetic wave is given by E = 56.5 sin ω(t - x/c)Nc^-1. Find the intensity of the wave if it is propagating along x-axis in the free space.

(Given ε₀ = 8.85 × 10^-12 C² N^-1 m^-2)

Options

• 5.65 Wm^-2

• 4.24 Wm^-2

• 1.9 × 10^-7 Wm^-2

•  56.5 Wm^-2

Answer 1

4.24 Wm^-2

Explanation:

Intensity of EM wave is given by

I = `1/2` ∈₀ E² C

= `1/2xx8.85xx10^-12xx(56.5)^2xx3xx10^8`

= 4.24 Wm^-2