A person can see clearly only upto a distance of `25 cm`. He wants to read a book placed at a distance of `50cm`. What kind of lens does he require for his spectacles and what must be its power ?

A person is unable to see objects nearer than 50 cm. He wants to read a book placed at a distance of 25 cm. Find the nature, focal length and power of the lens he requires for his spectacles.

The distance of distinct vision of a person is 50 cm. He wants to read a book placed at 25 cm. What should be the focal length of the spectacles ?

A short-sighted person can read a book only up to 15 cm from his eyes. To read a book placed at a distance of 25 cm from him what type of spectacles should he use? What be the power of the spectacles?

The distance of distinct vision of a person is 50 cm . He wants to read a book placed at 25 cm . What should be the focal length of the spectacles ?

A person cannot clearly see distance more than 40 cm. He is advised to use lens of power.

A student can distinctly see the object upto a distance 15 cm . He wants to see the black board at a distance of 3m . Focal length and power of lens used respectively will be

A person cannot see beyond a distance of 50 cm.The power of corrective lens required to see distant object is