A beam of light of wavelength 650 nm is incident along the normal to two closely spaced parallel glass plates.For what air gap separation between the plates will the transmitted beam be of maximum intensity? (1 nm = 10^-9 m)

Question

Quizplus · Accepted Answer

The condition for maximum intensity in transmitted light through thin film interference is when the path difference is an integral multiple of the wavelength. For normal incidence, the path difference is twice the air gap. Thus, 2d = mλ, where m is an integer. For maximum intensity, m = 1, so d = λ/2 = 650 nm / 2 = 325 nm.

A Beam of Light of Wavelength 650 Nm Is Incident