question_answer

What changes in the interference pattern in Young's double slit experiment will be observed when (i) light of smaller frequency is used?  (ii) the apparatus is immersed in water?

Answer:

                In Young's double slit experiment, the fringe width is given by \[\beta =\frac{D\lambda }{d}=\frac{Dc}{dv}\] Clearly, (i) When light of smaller frequency \[\left( \text{v} \right)\] is  used, fringe width increases. (ii) Wavelength of light in water decreases, so fringe width \[\text{(}\beta \propto \lambda \text{)}\] also decreases.