A light wave is incident normally on a glass slab of refractive index 1.5. If 4% of light gets reflected and the amplitude of the electric field of the incident light is 30V/m, then the amplitude of the electric field for the wave propagating in the glass medium will be:
Options

Question

A light wave is incident normally on a glass slab of refractive index 1.5. If 4% of light gets reflected and the amplitude of the electric field of the incident light is 30V/m, then the amplitude of the electric field for the wave propagating in the glass medium will be:

Options

G1 Physics · Accepted Answer

The transmitted intensity is 96% of the incident intensity. For a non-magnetic dielectric, I∝nE². Thus 1.5Eₜ²=0.96Eᵢ², giving Eₜ=30√(0.96/1.5)=24 V m⁻¹. Option B.