[" A point source of light is placed at a distance of "2ffrom],[" a converging lens of focal length "f" .The intensity on the "],[" other side of the lens is maximum at a distance "],[" (a) "fquad (b)" between "f" and "2f(c)2f(d)" more than "2f" ."]

A point source of light is placed at a distance of 2f from a converging lens of focal length f. The intensity on the other side of the lens is maximum at a distance

A point source of light is placed at a distance of 2f from a converging lens of focal length f. The intensity onteh other side of the lens is maximum at a distance

A point source of light is placed at a distance of 2f from a converging lens of focal length f. The intensity onteh other side of the lens is maximum at a distance

An object is placed at a distance of 20 cm from a convex lens of focal length 10 cm . The image is formed on the other side of the lens at a distance

A point source of light is placed at 2f from a converging lens of focal length f. A flat mirror is placed on the other side of the lens at a distanc d such that rays reflected from the mirror are parallel after passing through the lens again. If f = 30 cm, then d is equal to

A point object is placed at a distance of 12 cm from a convex lens of focal length 10 cm. On the other side of the lens, a convex mirror is placed at a distance of 10 cm from the lens such that the image formed by the combination coincides with the object itself. The focal length of the convex mirror is

A point object is placed at a distance of 12 cm from a convex lens of focal length 10 cm. On the other side of the lens, a convex mirror is placed at a distance of 10 cm from the lens such that the image formed by the combination coincides with the object itself. The focal length of the convex mirror is

A point source of light is kept at a distance of 15cm from a converging lens,on its optical axis.The focal length of the lens is 10cm and its diameter is 3cm ,A screen is placed on the other side of the lens ,perpendicular to the axis of lens,at a distance 20cm from it.Then find the area of the illuminated part of the screen?