The filament of lamp is 80 cm from a screen and a converging lens forms an image of it on a screen, magnified three times. Find the distance of the lens from the filament and the focal length of the lens.

If the focal length of the lens is 20 cm, find the distance of the image from the lens in the following figure?

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

A pin of length 2.00 cm is placed perpendicular to the principal axis of a converging lens. An inverted image of size 1.00 cm is formed at a distance of 40.0 cm from the pin. Find the focal length of the lens and its distance from the pin.

A convex lens is used to throw on a screen 10 m from the lens, a magnified image of an object. If the magnification is to be 19 , find the focal length of the lens.

A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen

A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen

A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen

A candle is placed 15cm in front of a lens. If the image of the candle captured on a screen is magnified two time, calculate the focal length and nature of the lens.

A lens placed between a candle and a fixed screen forms a real triply magnified image of the candle on the screen. When the lens is moved away form the candle by 0.8m without changing the position of the candle, a real image one-third the size of the candle is formed on the screen. Determine the focal length of the 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 lens is