Question

A uniform film of a material that has index of refraction 1.30 covers the front surface of a pane made of glass with index of refraction 1.55. When a beam of monochromatic light initially traveling in air strikes the film at normal incidence, the minimum film thickness for which the light reflected from the air-film interface and the light reflected from the film-glass interface cancel is 115 nm .
Part A
What is the energy of each photon in the light beam?

Answer 1

Answer:

The energy of each photon in the light beam is $1.73\times10^{-18}\ J$.

Explanation:

Given that,

Index of refraction of glass =1.55

Index of refraction of material =1.30

Wavelength = 115 nm

We need to calculate the energy of each photon in the light beam

Using formula of energy

$E=\dfrac{hc}{\lambda}$

Where, h = Planck constant

$\lambda$=wavelength

c = speed of light

Put the value into formula

$E=\dfrac{6.63\times10^{-34}\times3\times10^{8}}{115\times10^{-9}}$

$E=1.73\times10^{-18}\ J$

Hence, The energy of each photon in the light beam is $1.73\times10^{-18}\ J$.