A man who cannot see clearly beyond `5m` wants to see starts clearly. He should use a lens of focal length

A person who can see objects clearly at a distance of 10cm , requires spectacles to be able to see clearly objects at a distance of 30 cm. what type of spectacle should he use? Find the focal length of the lens.

A Person who can see objects clearly at a distance of 10cm, required spectacles to be able ot see clearly objects at a distance of 30cm. What types of spectacle should he use? Find the focal length of the lens.

Who can see nearer objects clearly ?

A man cannot see clearly the objects beyond a distance of 20 cm from his eyes. To see distant objects clearly he must use which kind of lenses and of what focal length

A short sighted person cannot see clearly beyond 2 m. The focal length of the concave lens to correct his eye to normal vision should be :

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