The image of the sun is formed on the photosensitive metal with a convex lens and the photoelectric saturation current obtained is I. If,the lens is replaced by another similar lens of half the diameter and double the focal-length, then photoelectric -current will be (Assume all lightpassing through lens felling on the photosensitive metal):

An image of the sun is formed by a lens, of the focal length of 30 cm, on the metal surface of a photoelectric cell and a photoelectric current I is produced. The lens forming the image is then replaced by another of the same diameter but of focal length 15 cm. The photoelectric current in this case is

An image of the sun is formed by a lens, of the focal length of 30 cm, on the metal surface of a photoelectric cell and a photoelectric current I is produced. The lens forming the image is then replaced by another of the same diameter but of focal length 15 cm. The photoelectric current in this case is

An image of the sun is formed on the metal surface of the photoelectric cell and it produces of current. The lens forming the image is then replaced by another of the same diameter but only half in focal length. a. What will be the effect on the photoelectric current? b. Is photoelectric emission possible at all frequencies ? c. If not give your explanation.

The image obtained while finding the focal length of a convex lens is ……………… .

When red light passing through a convex lens is replaced by light of blue colour, how will the focal length of the lens change ?

A convex lens forms the image of the sun at a distance of 10 cm. Where will be the image when another lens of same power but double the aperture is used ?

A convex lens forms the image of the sun at a distance of 10 cm. Where will be the image when Another lens of same aperture but double the power is used?

A convex lens is used to obtain a magnified image of an object on a screen . The object is at a distance 10 m from the lens . If the magnification is 19. the focal length of the lens is