Light Worksheet-1

Light Worksheet-1

1. Lunar eclipse is more frequent as compared to solar eclipse because:

(a) the earth forms a much bigger shadow which always reaches the moon

(b) the moon takes longer time to come out of the earth's shadow

(c) both

(d) None of these

2. When the sun, the moon and the earth happen to be in the same straight line and the same plane, such that the moon is in the middle, the eclipse caused is known as :

(a) solar eclipse                            (b) lunar eclipse

(c) Solar or lunar                          (d) None of these

3. A source of light which is larger than a point source of light is called :

(a) bigger source of light

(b) larger source of light

(c) extended source of light

(d) None of these

4. Sunlight passing through a small rectangular hole may be called as:

(a) convergent beam                   (b) divergent beam

(c) parallel beam                          (d) None of these

5. The old unit of luminosity of light is :

(a) watt                                           (b) candle power

(c) lumen                                        (d) watt or lumen

6. A mirage is observed when

(a) Density of air decreases with increase of height

(b) Density of air increases with height

(c) Refractive index of air decreases with increase of height

(d) Earth acts like a mirror

7. Which one of the following statements regarding a rainbow is correct?

(a) It is always seen as a circle

(b) The order of colours is always (from the top to bottom as seen from the ground) violet, indigo, blue, green, yellow, orange, red.

(c) Its order of colours is always (from the top to bottom as seen from the ground) red, orange, yellow, green, blue, indigo, violet.

(d) The order of colours can be either violet to red or red to violet depending upon the time of the day.

8. Which one shows lateral inversion

(a) Plane Mirror

(b) Convex Mirror

(c) Concave Mirror

(d) None of these

9. The image which can be obtained on screen is called

(a) Erect             (b) Real              (c) Virtual          (d) Inverted

10. When a light ray is reflected repeatedly by a set of parallel plane mirrors, the intensity of light rays decreases after some reflections. This is because of

(a) Poor reflection from mirrors

(b) Absorption of some amount of light by mirrors

(c) Dispersion of light when the rays travel through the atmosphere

(d) Scattering of light by the mirrors

Answer Key:

1. (c)
2. (a)
3. (c)
4. (c)
5. (b)
6. (a)
7. (c)
8. (a)
9. (b)
10. (b)