Question

What minimum separation between two parallel plates of glass (nglass =1.5) produces constructive interference for the reflected light with a 710 nm wavelength if the gap between the plates is filled with oil with noil =1.8?

Answer 1

The value is
`t = 9.861 *10^(-8) \ m`

Step-by-step explanation:

From the question we are told that

The refractive index of glass is
`n_(glass) = 1.5`

The wavelength is
`\lambda = 710 nm = (710)/(1 * 10^9) = 710*10^(-9) \ m`

The refractive index of oil is
`n_(oil) = 1.8`

Generally the condition for refractive index is mathematically represented as

`2 * t = [m + (1)/(2) ] (\lambda)/(n_(oil))`

Where t is the separation between two parallel plates of glass , now at minimum m which is the order of maxima produced is = 0

So

`2 * t = [0 + (1)/(2) ] (710 *10^(-9))/(1.8)`

`t = 9.861 *10^(-8) \ m`