If object is placed at 25 cm in front of a concave mirror of focal length 15 cm, then find out the image distance v.

Stars twinkle because:

If we shine green light on a tree, the tree will

Match the following lenses/mirrors with their correct applications.
Column-I (Lenses/Mirrors): i. Concave mirror, ii. Convex mirror, iii. Convex lens, iv. Concave lens
Column-II (Application): p. Used in cameras and projectors for focusing light, q. Used in correcting myopia (short-sightedness), r. Used in vehicles for rear-viewing, s. Used in shaving to produce magnified upright image
Select the correct matching option:

Which of the following correctly represents the sequence of colours observed on the screen when white light passes through a prism in its standard orientation?

We cannot see in the fog, because

The cause of diamond shine is

A boy stands at 30 cm distance in front of a mirror. He sees his direct image whose height is 1/5 of his actual height. Which mirror does he use?