A Young's double slit apparatus produces interference fringes of width 1.2 ~mm on a screen when the experiment is performed in air. If the entire apparatus is immersed in a transparent liquid of refractive index 4 3 , the new fringe width will be

Step-by-step solution

The fringe width in air is given by = D d When the entire apparatus is immersed in a liquid of refractive index , the wavelength of light in the liquid becomes ' = . The new fringe width ' is: ' = ' D d = D d = Substitute the given values: = 1.2 ~mm = 4 3 ' = 1.2 4 3 = 1.2 3 4 = 0.9 ~mm Answer: 0.9 ~mm