Question

In a youngs double slit experiment the fringe width is b if the entire arrangement is now placed inside a liquid of refractive index u the fringe width will be

Answer 1

Answer:

The new fringe width will be b/u

Explanation:

If the screen distance id D, distance between the slits is d and the wave length is λ

then the fringe width is given by

b = λD/d

When the arrangement is immerse in a liquid of refractive index u then the new wavelength is 1/u times the original wavelength

If the new wavelength is λ' then

λ' = λ/n

Therefore, the new fringe width will be

b' = λ'D/d

$b'=\frac{\lambda D}{ud}$

or, b' = b/u

Therefore the fringe width will decrease by a factor of u.

Hope this helps.