Amichelson interferometer operating at a 500 nm wavelength has a 3.73-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then, a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.

how many bright-dark-bright fringe shifts are observed as the cell fills with air?

The number of bright-dark fringe is 42

Solution:

As per the question:

Wavelength of light,

Length of the glass cell, x = 3.73 cm = 0.0373 m

Refractive index,

Now,

To calculate the bright-dark fringe shifts, we use the formula given below:

Now, substituting the appropriate values in the above formula:

≈ 42

x+2 because it just doubles hon so the pattern can actually tell you the expression.

so for example,

if x=2 then 2+2 is 4

if x=4 then 4+4 is 8

and so on and so forth.

i really hope that this makes sense and you out in a way hon: )