Question

A researcher measures the thickness of a layer of benzene (n = 1.50) floating on water by shining monochromatic light onto the film and varying the wavelength of the light. She finds that light of wavelength 590 nmnm is reflected most strongly from the film. What does she calculate for the minimum thickness of the film? Express your answer with the appropriate units.

Answer 1

98.33nm

Step-by-step explanation:

given:

refractive index 'n' = 1.50

wavelength of light' λ' = 590 nm

Required:

minimum thickness 't' = ?

By using formula

2nt= (m+
`(1)/(2)`)λ

where m=0,1,2,3..

For minimum thickness, m=0

2nt= λ/2

2 x 1.5 x t= 590 x
`10^-^9` /2

t=98.33 x
`10^-^9`m

t=98.33nm

Thus, minimum thickness of the film is 98.33nm