One face of a rectangular glass plate 6 cm thick is silvered. An object held 8 cm in front of the first face, forms an image 12 cm behind the silvered face. The refractive index of the glass is

Options

A. 0.4
B. 0.8
C. 1.2
D. 1.6

Answer

C

Explanation

x + 8 = 12 + 6 − x
`rArr " " x `= 5 cm.
Now, `n = (t)/(x) = (6)/(5) = 1.2`
(Here x is the apparent position of silvered face)