Practicing Success
A two slit Young's experiment is done with monochromatic light of wavelength 6000 Å. Slits are 2 mm apart and fringes are observed on a screen placed 10 cm away from the slits. If a transparent plate of thickness 0.5 mm is placed in front of one of the slit, interference pattern shifts by 5 mm. Then refractive index of transparent plate should be |
1.1 1.2 1.3 1.5 |
1.2 |
$(\mu-1) t=\frac{x d}{D}$ or $\mu=1+\frac{x d}{D t}$ or $\mu=1+\frac{0.5 \times 0.2}{10 \times 0.05}=1+0.2=1.2$ |