Available Answers

1. 1.

   Write true or false. Correct the false statements.

   1. A concave mirror is also known as a diverging mirror.
   2. The focal length of a special mirror is twice the radius of curvature.
   3. While sketching ray diagrams, the object should always be kept in front of the polished surface.
   4. A ray of light incident at the pole of a spherical mirror is reflected along a path, making the same angle with  the principal axis, as the incident ray does.
   5. A ray of light parallel to the principal axis, after reflection from a concave mirror, will pass through the centre of curvature.
2. 2.

   Fill in the blanks.

   1. A ________________________________ image can be obtained on a screen.
   2. The ______________________________ of a mirror denotes its size.
   3. The length of the straight line joining two opposite extreme points on the periphery of a spherical mirror is called ____________________________________________.
   4. The centre of the hollow sphere of which a spherical mirror forms a part is called its __________________________.
   5. A virtual image is always _________________________________________.
   6. In a concave mirror, an incident ray passing through the focus is reflected parallel to the _______________________________________________.
3. 3.

   Define refraction. State the two laws of reflection.

4. 4.

   What is the speed of light in vacuum?

5. 5.

   Define refractive index.

6. 6.

   Give two example of refraction of light.