Question

A mica slit of thickness t and refractive index \( \mu \) is introduced in the ray from the first source \( S_1 \). By how much distance of fringes pattern will be displaced?

• A. \( \frac{D}{\mu - 1} t \)
• B. \( \frac{D}{\mu} t \)
• C. \( \frac{D}{\mu - 1} \)
• D. \( \frac{D}{\mu} \)

Hint:

Introducing a mica slit causes a displacement of the fringe pattern proportional to its thickness and inversely proportional to the refractive index.

Answer 1

The Correct Option is B

Step 1: Displacement of fringes formula.
When a mica slit is introduced, the displacement of the fringes is proportional to the thickness of the slit and inversely proportional to the refractive index \( \mu \). The displacement is given by: \[ \text{Displacement} = \frac{D}{\mu} t \] where \( D \) is the distance between the slits and the screen, and \( t \) is the thickness of the mica slit.
Thus, the correct answer is (2).