A transparent film of thickness and index of refraction is deposited on a glass…

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics

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

(b)

m = 4

(c)

m = 6

(d)

m = 3