Ray Optics and ...

A person cannot see the object distinctly, when placed at a distance less than 100cm. What is the power of the spectacles that he should use to see clearly the objects placed at 25 cm?​

An astronomical telescope has a large aperture to:

Resolving power of a telescope depends on

A far- sighted person has lost his spectacles. He can read a book at usual distance by looking through a pin hole because while looking through the pin hole:

A myopic person can see things clearly if they lie between 8 cm and 100 cm from his eye. The lens will enable him to see the moon distinctly if its focal length is:​

The earth takes 24 h to rotate once about its axis. How much time does the sun take to shift by 1º when viewed from the earth?​

A slide projector gives a magnification of 10. If a slide of dimensions 3 cm x 2 cm is projected on the screen, the area of the image on the screen is:​

What happens to the magnifying power of microscope, when its length increases?​

The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the objective and eyepiece is found to be 20 cm. The focal lengths of lenses are:​

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?​