In the figure shown , a point object O is placed in air on the principal axis. The radius of curvature of the spherical surfaces is `60 cm.` I is the final image formed after all reflections and refractions.

Options

A. If `x=120 cm,` then I is formed on O for any value of y
B. If `x=240 cm,` then I is formed on O for any value of `y=360 cm`
C. If `x=240 cm,` then I is formed on O for any value of y
D. None of these

Answer

A

Explanation

Using `mu_2/u-mu_1/u=(mu_2-mu_1)/R` we get
`(3//2)/oo-1.0/(-x)=(3//2-1)/(+60)`
`:. x=120 cm`
Hence, for `x=120 cm,` rays of light becomes
parallel to principal axis and fall normal to
polished surface.
Hence, rays retrace their path.