A convex lens has focal length 5 m. At what distance should an object be placed, so as to have a real image magnified twice?

Establish a relationship between object distance, image distance and focal length for a thin concave lens. At w hat distance from a convex lens of focal length 20 cm m ust on object be placed in order th a t an erect image may be formed twice the size of the object?

stablish a relationship between object distance, image distance and focal length for a thin concave lens. At what distance from a convex lens of focal length 20 cm must on object be placed in order that an erect image may be formed twice the size of the object?

A terrestrial telescope has an objective of focal length 180cm and an eyepiece of focal length 5.0cm. The erecting lens has focal length of 3.5cm. What is the separation betwee the objective and the eyepiece?What is the magnifying power of the telescope?

At what distance from a concave mirror of focal length 15 cm must an object be placed, so that the linear size of the image be half that of the object?

A convex lens of focal length 5 cm is used as a simple microscope. What is its magnifying power ?

A convex lens of focal length f_1 and a concave lens of focal length f_2 are placed in contact. The focal length of the combination is f. Then

A convex lens of focal length 5 cm is used as a simple microscope. What will be the magnifying power when the image is formed at the least distance of distinct vision?

A convex lens of focal length 20 cm forms a real image of a point object at a distance of 50 cm from the convex lens. A concave lens is placed 10 cm behind the convex lens on the image side. On placing a plane mirror on the image side and facing the concave lens, it is observed that the final image, now coincides with the object itself. Find the focal length of the concave lens. Will there be any change in position of the image, if the mirror is moved parallel to its reflecting surface?