Скачать или смотреть Ray Optics-NCERT solved numericals on Lenses-class 12

NCERT solved numericals on lenses are very important for class 12 Physics. Here the students may get detailed concept of numericals based on lens.
(9.20) A screen is placed 90cm from an object. The image of the object on
the screen is formed by a convex lens at two different locations
separated by 20cm. Determine the focal length of the lens.
(9.19) The image of a small electric bulb fixed on the wall of a room is to be
obtained on the opposite wall 3m away by means of a large convex
lens. What is the maximum possible focal length of the lens required
for the purpose?
(9.10) What is the focal length of a convex lens of focal length 30cm in
contact with a concave lens of focal length 20cm? Is the system a
converging or a diverging lens? Ignore thickness of the lenses.
(9.8 )A beam of light converges at a point P. Now a lens is placed in the
path of the convergent beam 12cm from P. At what point does the
beam converge if the lens is (a) a convex lens of focal length 20cm,
and (b) a concave lens of focal length 16cm?