A glass slab of thickness `3cm` and refractive index `3//2` is placed on ink mark on a piece of paper. For a person looking at the mark at a distance `5.0 cm` above it, the distance of the mark will appear to be

A glass slab of thickness 3 cm and refractive index 3/2 is placed on ink mark on a piece of paper. For a person looking at the mark at a distance 2 cm above it, the distance of the mark will appear to be in cm

A glass slab (n - 1.5) of thickness 3.0 cm is placed on an ink spot. A person looks at it from a distance 5.0 cm above the ink spot. The distance of the spot will appear to be :

A glass slab of thickness 3cm and refractive index 1.5 is placed in front of a concave mirror of focal length 20cm. Where should a point object be placed if it is to image on to itself?

A glass slab of thickness 3cm and refractive index 1.5 is placed in front of a concave mirror of focal length 20cm. Where should a poing object be placed if it is to image on to itself?

A mark is made on the bottom of a vessel and over this mark, a glass slab to thickness 3.5 cm and refractive index (7)/(4) is placed. Now water (refractive inidex, (4)/(3)) is poured into the vessel so that the surface of water is 8 cm above the upper surface of the slab. Looking down of normally through the water, the apparent depth of the mark below the surface of water will be :

A flat glass slab of thickness 6 cm and index 1.5 is placed in front of a plane mirror. An observer is standing behind the glass slab and looking at the mirror. The actual distance of the observer from the mirror is 50 cm. The distance of his image from himself, as seen by the observer is