In a Young's double slit experiment, it is desired to modify the setup such that the new angular fringe width is 1.5 times its initial value, and the new linear fringe width is 3 times its initial value. Which of the following combinations of changes will achieve this?

Step-by-step solution

Let the initial angular fringe width be and the initial linear fringe width be . The new angular fringe width is ' = 1.5 . The new linear fringe width is ' = 3 . The linear fringe width is given by = D , which implies the screen distance is D = . The new screen distance required is: D' = ' ' = 3 1.5 = 2 ( ) = 2 D Thus, the screen distance must be doubled. The angular fringe width is given by = d . To achieve ' = 1.5 , we can either increase the wavelength by 50 % (so ' = 1.5 ) or decrease the slit separation d by 3