Situation 17.1
A 360 nm thick oil film floats on the surface of the water.The indices of refraction of the oil and the water are 1.50 and 1.33,respectively.The surface of the oil is illuminated from above at normal incidence with white light.
-In Situation 17.1,the two wavelengths of light in the 400 nm to 800 nm wavelength band that are most strongly reflected,in nm,are closest to:

Question

Quizplus · Accepted Answer

The condition for constructive interference in thin films is given by $2nt = m\lambda$, where $n$ is the refractive index, $t$ is the thickness, and $\lambda$ is the wavelength. For the oil film, $2 \times 1.50 \times 360 \, \text{nm} = m\lambda$. Solving for $m$ gives wavelengths around 430 nm and 720 nm.

Situation 17.1 A 360 Nm Thick Oil Film Floats on the Surface