A parallel beam of light is incident on a lens of focal length 10cm. A parallel slab of refractive index 1.5 and thickness 3 cm is placed on the other side of the lens. The nature of the final image from the lens slab combination is: (Assume rays paraxial)

Options

A. At distance of 11 cm and image is vertual if X=12 cm
B. At distance of 11 cm and image virtual if X=14 cm
C. At the Distance of 11 cm and image is virtual if X=16 cm
D. All of the above

Answer

D

Explanation

As rays are parallel to the principal axis, image is created by lence at focus.
By placing of glass-slab
Shift `=(1-1/(mu)).t`
`=(1-1/1.5) 3=1 cm`.
Irrespective of separation
Image is shifted to the right by 1 cm
Total distance from lese 10+1=11 cm
Image will be virtual if X is greter than 11 cm