Question

What is the minimum thickness of a soap bubble needed for constructive interference in reflected light, if the light incident on the film is 750 nm? Assume that the refractive index for the film is `n=1.33`
A. 282 nm
B. 70.5 nm
C. 141 nm
D. 387 nm

Answer 1

Correct Answer - C
As, `2mut_("min")=(lambda)/(2)`
` :. t_("min")=(lambda)/(4mu)=(750)/(4xx1.33)=141 nm`