When a biconvex lens of glass having refractive index 1.47 is dipped in a liquid, it acts as a plane sheet of glass. This implies that the liquid must have refractive index,

Options

A. less that one
B. less than that of glass
C. greater than that of glass
D. equal to that of glass

Answer

A

Explanation

According to len.s maker formula, `(1)/(f)=((n_(2))/(n_(1))-1)((1)/(R_(1))-(1)/(R_(2)))`. Biconvex lens dipped in a liquid, acts as a plane sheet of glass, `f = oo : (1)/(f) = 0`
`(n_(2))/(n_(1))-1=0:n_(2)=n_(1)`