Usually, we neglect the thickness of the mirror and assume that only reflection takes place. But what will happen if a point object is placed in front of a thick plane mirror? How do we locate the multiple images formed?
A point source of light S is placed at the bottom of a vessel containing a liquid of refracting index 5/3. A person is viewing the source from above the surface, there is an opaque disc of radius 2 cm floating on the surface of the liquid such that the center of the disc is vertically above the source S. The liquid from the vessel is gradually drained out through a tap. The maximum height of the liquid for which the source cannot be seen from above is?