The focal length of a convex lens is f. How does the size of the image placed in front of it changes as the object is brought progressively closer to the focus from a distance which is just greater than 2f?

Choose the correct alternative corresponding to the object distance 'u', image distance 'v' and the focal length 'F' of a converging lens from the following . The average speed of the image as the object moves with the uniform speed from distance (3F)/(4) to (F)/(2) is greater than the average speed of the image as the object moves with same speed from distance (F)/(2) "to" (F)/(4) The minimum distance between a real object and its real image in case of a converging lens is 4F where F is its focal length.

Focal length of concave mirror is f and ratio of heights of object to image for an object at x distance from mirror is .....

Give object and image distances, type, size and magnification for object placed in front of thin lens.

The focal length of a thin biconvex lens is 20 cm . When an object is moved from a distance of 25 cm in front of it to 50 cm , the magni-fication of its image changes from m_(25) to m_(50) . The ratio (m_(25))/(m_(50)) is.

A thin convex lens from a real Image of a certain object 'p' times it size .The size of real image become 'q' times that of object when the lens is moved nearer to the object by a distance 'a' find focal length of the lens?

What is the focal length of lens if the image distance remain same by keeping object at 24 cm and 16 cm from lens ?

A convex lens of focal length f forms an image which is 1/3 times the size of the object. Then, the distance of object from the lends is

For a thin convex lens when the heights of the object is double than its image, its object distance is equal to ....... Focal length of a lens is f.

An object of size 3.0cm is placed 14cm in front of a concave lens of focal length 21cm. Describe the image produced by the lens. What happens if the object is moved further away from the lens?

A biconvex lens of focal length f forms a circular image of radius r of sun in focal plane . Then which option is correct