For a person with hypermeteropia, the near point has moved to 1.5 m. calculate the focal length of the correction lens in order to make his eyes normal.

Calculate the focal length of a corrective lens having power + 2.5 D .

The focal length of a normal eye lens is about

The focal length of the concave lens is 7 m. Calculate the power of lens.

The distance of the eye lens from the retina is x. For a normal eye, the maximum focal length of the eye lens

What is the focal length of a convex lens ( mu = 1.5) with radii of curvature R.

The eyepice of an astronomicasl telescope has a focasl length of 10 cm. The telescope is focussed for normal vision of distant objects when the tube length is 1.0 m. find the focal length of the bjective and the magnifying power of the telescope.

The total magnification produced by a compound microscopeis 20. The magnification produced by the eye piece is 5. The microscope is focussed on a certain object. The distance between the objective and eyepiece is observed to be 14 cm. If least distance of distinct vision is 20 cm, calculate the focal length of the objective and the eye piece.

A simple microscope has a magnifying power of 3.0 when the image is formed at the near point (25 cm) of a normal eye. (a) What is its focal length? (b) What will be its magnifying power if the image is formed at infinity?