. A convex lens forms an image of a point object kept on its principal axis. The object is 50 cm away from the lens and image is also 50 cm away from the lens. If a glass slab ( μ = 1.5 , thickness =

Question

. A convex lens forms an image of a point object kept on its principal axis. The object is 50 cm away from the lens and image is also 50 cm away from the lens. If a glass slab ( μ = 1.5 , thickness = 3 cm ) is placed between the object and the lens, the image shifts by :

TestHub · Accepted Answer

The slab shifts the apparent object toward the lens by $t (1 - \frac{1}{μ}) = 3 (1 - \frac{2}{3}) = 1 cm$ , so u' = 49 cm while f = 25 cm (since u = v = 50 cm originally).

$\frac{1}{v ^{'}} = \frac{1}{25} - \frac{1}{49} = \frac{24}{1225} \Rightarrow v^{'} = \frac{1225}{24} = 51.04 cm$

Shift = $51.04 - 50 = \frac{25}{24} cm$ away from the lens. Hence (B).

Physics - Geometrical Optics Question with Solution | TestHub

Options:

Doubts & Discussion