The focal length of convex tens is `f` and the distance of an object from the principal focus is x. The ratio of the size of the real image to the size of the object is

The focal length of a concave mirror is f and the distance of the object from the principal focus is x . The magnification of the image produced is

What is the distance of an object from a concave mirror of focal length 20 cm so that the size of the real image is three times the size of the object ?

Assertion : The focal length of the mirrorr is f and distance of the object from the focus is u , the magnification of the mirror is f//u . Reason : Magnification =("Size of the image")/("Size of object" )

Find the position of the object for a convex mirror of focal length 20 cm, when the size of the image is half the size of the object.

The focal length of a convex lens is 30 cm and the size of image is quarter of the object.Them,the object distance is

The focal length of convex lens is 30 cm and the size of image is quarter of the object, then the object distance is

The focal length of a convex lens is 30cm and the size of the real image is (1)/(4)th of the object. Then the object distance is