Question

Monochromatic light of wavelength of 600nm is used in a YDSE. One of the slits is covered by a transparent sheet of thickness $1.8\times {10}^{-5}m$ made of a material of refractive index 1.6. How many fringes will shift due to the introduction of the sheet?

• A. 18
• B. 12
• C. 20
• D. 10

Answer 1

The correct option is A

18

$n=\frac{(\mu -1)t}{\lambda }$
$=\frac{(1.6-1)1.8\times {10}^{-5}}{600\times {10}^{-9}}$
$=\frac{0.6\times 18\times {10}^{-6}}{6\times {10}^{-7}}$ ; Shift = 18