### Light - Exemplar Solutions 1

CBSE Class 8 Science
NCERT Exemplar Solutions
CHAPTER – 16
LIGHT

MULTIPLE CHOICE QUESTIONS
1. Part of the eye which controls the light entering is called
(a) iris
(b) cornea
(c) lens
(d) retina
Ans: (a) iris
Explanation: The iris controls the amount of light entering in the eye.

2. We can see a non-luminous object when light :
(a) emitted by the object falls on the eye.
(b) is reflected from the object towards our eye.
(c) completely passes through the object.
(d) gets completely absorbed by the object.
Ans: (b) is reflected from the object towards our eye.
Explanation: A non-luminous object does not produce its own light, but it reflects light from other sources. We can see a non-luminous object when light is reflected from the object towards our eyes.

3. Light is falling on surface S1, S2, S3 as shown in Fig.16.1.
Surfaces on which the angle of incidence is equal to the angle of reflection is/are
(a) S1 only
(b) S1 and S2 only
(c) S2 and S3
(d) all the three surfaces
Ans: (d) all the three surfaces
Explanation: In all the three surface the angle of incidence is equal to the angle of reflection.

4. A tiny mirror M is fixed on a piece of cardboard placed on a table. The cardboard is illuminated by light from a bulb. The position of eye with respect to position of bulb is shown in Fig.16.2 as A, B, C and D. In which position mirror will be visible?
a. A   b. B    c. C    d. D
Ans: (a) A
Explanation: The mirror will be visible in position A.

5. A small hole P is made in a piece of cardboard. The hole is illuminated by a torch as shown in Fig. 16.3. The point of light coming out of the hole falls on a mirror.
At which point, should the eye be placed so that the hole can be seen?
(a) A    (b) B     (c) C     (d) D
Ans: (a) A
Explanation: Eye should be placed at A to see the hole. Since, angle of incidence should be equal to angle of reflection.

6. Two mirrors A and B are placed at right angles to each other as shown in Fig.16.4.
A ray of light incident on mirror A at an angle of 25° falls on mirror B after reflection. The angle of reflection for the ray reflected from mirror B would be
(a) 25o    (b) 50o    (c) 65o    (d) 115o
Ans: (c) 65°
Explanation: The angle of reflection for that ray reflected from mirror B would be 65o.

7. Which of the following statements is correct regarding rods and cones in the human eye ?
(a) Cones are sensitive to dim light.
(b) Cones are sensitive to bright light.
(c) Rods are sensitive to bright light.
(d) Rods can sense colour.
Ans: (b) Cones are sensitive to bright light.
Explanation: Cones are sensitive to bright light. Rods are sensitive to dim light.

8. In the figure of the human eye (Fig.16.5), the cornea is represented by the letter
(a) A   (b) B    (c) C    (d) D
Ans: (c) C
Explanation: The transparent front part of an eye is called cornea.