Physics

Problem

A transparent film of thickness

t = 750\,\text{nm}

and index of refraction

n = 1.50

is deposited on a glass substrate of index

n = 1.60

. Light of wavelength

500\,\text{nm}

in air is incident normally on the film. The reflected light shows a dark fringe (destructive interference). What is the integer order

m

associated with this destructive interference? a)

m = 5

m = 4

m = 6

m = 3