Find the thickness fo a plate which will produce a change in optical path equal to half th ewavelength λ of the light passing through it normally. The refractive index of the plate is μ
a plate of thickness t made of a material of refractive index μ is placed in front of one of the slits in a double slit experiment (a) Find the change in th eoptical path due to introduction of th plate. (b) What should be the minimum thickness t which will make the intensity at the centre of the fringe pattern zero? WAvelength of the light used is λ Neglect any absorption of light in the plate.