In Young.s double silt experiment the y co-ordinates of central maxima and 10th maxima are 2cm and 5 cm respectively. When the apparatus is immersed in a liquid of refractive index `1.5` the corresponding y co-ordinates will be :

Explanation

Fringe width `beta propto lambda`. Therefore, and hence `beta` will decrease `1.5` times when immersed in liquid. The distance between central maximum and 10th maxima is 3 cm in vacuum. When immersed in liquid it will reduce to `(3)/(1.5)= 2cm`. Position of central maxima will not change while 10th maxima will be obtained at y= 4cm.