A point object is placed on the principal axis of a convex lens (f = 15 cm) at a distance of 30 cm from it. A glass plate (μ = 1.50) of thickness 1 cm is placed on the other side of the lens perpendicular to the axis. Locate the image of the point object.
focal length of the convex lens
= 15cm
Distance of object from the lens, u = -30cm

By using lens formula,
![]()
![]()
![]()
The image is formed at 30 cm of right side due to lens only. Again, shift due to glass slab is,
![]()
![]()
![]()
The image will be formed at 30 + 0.33 = 30.33 cm from the lens on right side.