An oil slick of uniform thickness floats on water

PHYSICS · Single correct · CBSE · Physics · Wave Optics · Wave Optics

Problem

An oil slick

\left(n=1.40\right)

of uniform thickness

110\,\text{nm}

floats on water

\left(n=1.33\right)

. White light in air strikes the oil at

45^{\circ}

from the normal. Which of the following is the shortest wavelength in air that will be constructively reinforced in the reflected light? (a)

3.7\times10^{2}\,\text{nm}

(b)

4.3\times10^{2}\,\text{nm}

(c)

5.3\times10^{2}\,\text{nm}

(d)

5.6\times10^{2}\,\text{nm}