Why is a normal eye not able to see clearly the objects placed closer than 25 cm?

For a long sighted man the least distance of distinct vision is 100 cm. Calculate the power of the lens that will enable him to see an object placed at a distance of 50 cm.

A person with a myopic eye is not able to see objects beyond 1.25 m from it. What is the nature, the focal length and power of the lens used to correct the' defect?

Why is it not possible to see an atom with naked eyes?

Why are we able to sip hot tea or milk faster from a saucer rather than a cup?

A concave lens of focal length 15cm forms an image 10cm from the lens. How far is the object placed from the lens? Draw the ray diagram.

Why should a simple magnifying glass be placed closer to the eye ?

The objective lens and eye piece lens of a Compound microscope have focal length 1.5cm and 5 cm respectively. The object is placed at a distance 1.8 cm. What is its magnification?

A concave mirror of focal length 8cm produces a real image of size 4cm when an object 2cm high is placed at a certain distance from the mirror . Find the position of the image and the object.