Question
93. A glass slab of thickness 4 centimetre contains the same number of waves as 5 centimetre of water when both are Traversed by the same monochromatic light if the refractive index of water is 4 by 3 what is that of glass 1) 5 by 3 2) 5 by 4 3) 16 by 15 4) 3 by 2