Question

When the same monochromatic ray of light travels through glass slab and through water, the number of waves in glass slab of thickness 6 cm is same as in water column of height 7 cm. If refractive index of glass is `1.5`, then refractive index of water is
A. 1.258
B. 1.269
C. 1.286
D. 1.31

Answer 1

Correct Answer - C
No. of waves is glass slab =No. of waves in water column.
`therefore mu_(g). H_(g) =mu_(w). H_(w)`
`therefore mu_(w)=(mu_(g).h_(g))/(hw)=(1.5 xx 6)/(7)`
`therefore mu_(w)=9/7=1.286`