question_answer

In Youngs experiment, using light of wavelength \[6000\overset{\text{o}}{\mathop{\text{A}}}\,\] fringe width at distance 2.5 m is obtained as 0.8 mm. If the entire apparatus is immersed in a liquid of refractive index 1.6, the fringe width will be:

A)  0.2 mm               

B)  0.4 mm

C)  0.5 mm               

D)  0.6 mm