Problem

A parallel beam of white light falls on a thin film whose refractive index is equal to

4/3

. The angle of incidence

i = 53^\circ

. What must be the minimum film thickness if the reflected light is to be coloured yellow (

\lambda

of yellow =

0.6 \mu\text{m}

) most intensively? (

\tan 53^\circ = 4/3

)