Science [ 1 mark questions ]

As a dentist’s head mirror: You would have seen a circular mirror attached to a band tied to the forehead of the dentist/ENT specialist. A parallel beam of light is made to fall on the concave mirror; this mirror focuses the light beam on a small area of the body (such as teeth, throat etc.).

The speed of light in vacuum is known to be almost exactly 300,000 km per second. In 1665 the Danish astronomer Ole Roemer first estimated the speed of light by observing one of the twelve moons of the planet Jupiter.

 If an object is placed at the focus of a concave mirror at infinity image is formed.

Concave mirror

Concave mirror is having a negative focal length.

Yes, at the point of incidence both laws of reflection will hold good.

No change. The focal length of a convex mirror does not depend on the nature of the medium.

It means that light travels 2.42 times faster in a vacuum than in a diamond.