Available Answers

1. 1.

   Tick (√) the correct options:

   1. A spherical mirror whose reflecting surface is curved inwards is called __________ mirror.
      1. concave
      2. convex
      3. plane
      4. none of these
   2. Shaving mirrors are __________.
      1. plane
      2. concave
      3. convex
      4. plano-convex
2. 2.

   Tick (√) the correct options:

   1. A man sees a magnified image of a closely kept object by holding a simple 'clear glass' device in his hand. The device is likely to be a ____________.
      1. concave mirror
      2. concave lens
      3. convex mirror
      4. convex lens
   2. A concave lens always produces a ____________.
      1. real, inverted and magnified image
      2. real, inverted and diminished image
      3. virtual, erect and magnified image
      4. virtual, erect and diminished image
   3. When a person moves closer to a plane mirror, the size of his image ____________.
      1. increases
      2. decreases
      3. remains the same
      4. first increases then decreases
   4. 'Make-up' mirrors are ____________ mirrors.
      1. concave
      2. convex
      3. plane
      4. all of these
3. 3.

   Look at the Fig. (a) given alongside and tick (√) the correct options:

   

   1. In Fig. (a), we are holding ______________.
      1. concave lens
      2. convex lens
      3. plane lens
      4. convex mirror
   2. In Fig. (a), the black paper ______________ after a few minutes.
      1. cools down
      2. starts spreading
      3. starts burning
      4. remains the same
4. 4.

   Fill in the blanks:

   1. ____________________ mirrors are used as rear-view mirrors in automobiles.
   2. The distance between the optical centre and the principal focus of the lens is called its ____________________.
   3. The band of seven colours formed on white screen when white light passes through a prism is called ____________________.
   4. The splitting of white light into seven colours is called ____________________ of light.
   5. ____________________ mirrors are used by dentists to see enlarged image of teeth.
   6. ____________________ lenses are used as reading glass.
   7. Sunlight (white light) is a combination of ____________________.
5. 5.

   State whether the following statements are true (T) or false (F). Rewrite the false statements correctly:

   1. The image formed by the plane mirror is real and erect.
   2. Concave mirrors are used in the headlights of car.
   3. The image formed by a convex lens is inverted, magnified and real, when an object is kept between the lens and the focus.
   4. Image that can be obtained on a screen is called a virtual image.
6. 6.

   Give one example of a virtual image.