The objective lens of a compound microscope produces magnification of 10. In order to get an overall magnification of 100 when image is formed at `25cm` from the eye, the focal length of the eye lens should be

An object is seen through a simple microscope of focal length 20 cm. Find the angular magnification produced, if the image is formed at 30 cm from the lens.

A simple magnifying lens is used in such a way that an image is formed at 25 cm away from the eye. In order to have 10 times magnification, the focal length of the lens should be

The magnification power of a convex lens of focal length 10cm, when the image is formed at the near point is

In a compound microscope magnification will be large, if the focal length of the eye piece is

A convex lens produces an image of a real object on a screen with a magnification of 1/2. When the lens is moved 30 cm away from the object, the magnification of the image on the screen is 2. The focal length of the lens is

(a) An object is seen through a simple microscope of focal length 12cm . Find the angular magnification produced if the image is formed at the near point of the eye which is 25cm away from it. (b) A 10D lens is used as a magnifier. Where shold the object be placed to obtain maximum angular magnification for a nirmal eye (near point = 25cm) ?