Monochromatic light of wavelength in air strikes a thick coating ( ) on glass ( ) at…

PHYSICS · Subjective · A Level · Physics · Waves · Waves

Problem

Monochromatic light of wavelength

550\,\text{nm}

in air strikes a

110\,\text{nm}

thick coating (

n=1.30

) on glass (

n=1.50

) at

30^{\circ}

to the normal. Indicate whether the reflected light at this wavelength will be at a brightness maximum or minimum.