An object 2.4 m in front of a lens forms a sharp image on a film 12 cm behind the lens. A glass plate 1cm thick, of refractive index 1.50 is interposed between lens and film with its plane faces parallel to film. At what distance (from lens) should object be shifted to be in sharp focus on film?
7.2 m
2.4 m
3.2 m
5.6 m
According to thin lens formula
When a glass plate is interposed between lens and film , so shift produced by it will be
to get image at film lens ,should form image at distance