Question

The intensity of a laser light is 53.10 W/m². Find the amplitude of the electric field oscillation in it.

पर्याय

• `200sqrt2` N/C

• 400 N/C

• 200 N/C

• 100 N/C

Answer 1

200 N/C

Explanation:
The intensity of an electromagnetic wave is related to the amplitude of the electric field by the following formula:

I = `1/2ε_0 E_0^2 c`

53.10 = `1/2 xx 8.85 xx 10^-12 xx E_0^2 xx 3 xx 10^8`

`E_0^2 = (53.10 xx 2)/(8.85 xx 10^-12 xx 3 xx 10^8)`

`E_0^2 = 106.2/(26.55 xx 10^-4)`

`E_0 = sqrt(4 xx 10^4)`

∴ E₀ = 200 N/C