Available Answers

1. 1.

   Tick (√) the correct options:

   1. Which of the following is a translucent material?
      1. air
      2. tissue paper
      3. brick
      4. stone
   2. A dark patch formed behind an opaque material is called a/an _______________.
      1. shadow
      2. image
      3. both (a) and (b)
      4. screen
2. 2.

   Tick (√) the correct options:

   1. Shadow of an object is always _______________.
      1. colourful
      2. white
      3. dark (black)
      4. transparent
   2. Pinhole camera is based on the principle of _______________.
      1. rectilinear propagation of light
      2. rectangular propagation of light
      3. circular propagation of light
      4. none of these
3. 3.

   Tick (√) the correct options:

   1. The material through which we can see clearly is called _______________ material.
      1. opaque
      2. transparent
      3. translucent
      4. none of these
   2. Which of the following is a non-luminous object?
      1. star
      2. firefly
      3. lighted candle
      4. the earth
   3. We are able to see image in a mirror due to _______________.
      1. reflection
      2. dispersion
      3. refraction
      4. lateral inversion
   4. We cannot see the candle flame through the bent rubber tube because _______________.
      1. light does not reach us
      2. light reflects
      3. light moves in a zigzag manner
      4. none of these
   5. Which of the following is not a translucent object?
      1. grounded glass
      2. cellophane paper
      3. butter paper
      4. tissue paper
   6. Which of the following is an opaque material?
      1. butter paper
      2. wood
      3. air
      4. water
4. 4.

   Match the following:

   Column A	Column B
   1. Transparent	(a) travels in a straight line
   2. Translucent	(b) air and glass
   3. Light	(c) dark
   4. Shadow	(d) butter paper and tissue paper

    

5. 5.

   Fill in the blanks:

   1. The Sun is a _______________ source of light.
   2. A _______________ is a dark patch formed behind an opaque object.
   3. A smooth or regular surface reflects the light in _______________ direction.
   4. A shadow only shows the _______________ of an object.
   5. An opaque substance on which a shadow is formed is called a _______________.
6. 6.

   Name three luminous objects.