Question

Answer in one word. 1. Friction acting between the two surfaces which are in contact and placed at rest __________ 2. This kind of surface shows greater friction __________ 3. Friction acting when an object rolls over the surface of another __________ 4. This friction is also known as drag.​

Answer 1

Explanation:

Mirrors, whose reflecting surfaces are curved and can be imagined as part of a sphere, are called spherical mirrors. If the reflecting surface of a spherical mirror is curved outwards, it is called a convex mirror. Whereas a mirror with a reflecting surface, which is bent inwards, is called a concave mirror. Concave mirrors reflect and focus incoming light rays (parallel) at a point, called the focus point. Depending on the distance of an object from the reflecting surface, different types of images are formed. Both kinds of mirrors are used in science and technology. These are used in daily life also. Concave mirrors are used as headlights, torches, head mirrors, solar furnaces, microscopes, telescopes, etc.