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

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 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

In a displacement method using lens, we obtain two images for separation of the lens d. One image is magnified as much as the other is diminshed . If m is the magnification of one image, find the focal length of the lens.

In a displacement method using lens, we obtain two images for separation of the lens d. One image is magnified as much as the other is diminshed . If m is the magnification of one image, find the focal length of the lens.

In a displacement method using lens, we obtain two images for separation of the lens d. One image is magnified as much as the other is diminshed . If m is the magnification of one image, find the focal length of the lens.

A convex lens forms an image of an object on a screen 30 cm from the lens. When the lens is moved 90 cm towards the object, then the image is again formed on the screen. Then, the focal length of the lens is

A convex lens forms an image of an object on a screen 30 cm from the lens. When the lens is moved 90 cm towards the object, then the image is again formed on the screen. Then, the focal length of the lens is