LIGHT

Part of the eye which controls the light entering is called

• (a) iris

• b) cornea

• (c) lens

• (d) retina

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.

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

• S1 only

• s2 and S3

• S1 and S2

• All surfaces

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 degree falls on mirror B after reflection. The angle of reflection for the ray reflected from mirror B would be

• 25

• 65

• 50

• 115

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.

In the figure of the human eye (Fig.16.5), the cornea is represented by the letter

• A

• B

• C

• D

Name the part of the eye which gives colour to the eyes.

• cornea

• iris

• pupil

• retina

The angle between incident ray and reflected ray is 60°. What is the value of angle of incidence?

• 30

• 35

• 120

• 60

The distance between the object and its image formed by a plane mirror appears to be 24 cm. What is the distance between the mirror and the object?

• 24 cm

• 12 cm

• 10 cm

• infinity

Boojho planned an activity to observe an object A through pipes as shown in Fig. 16.8, so that he could see objects which he could not directly see.

How many mirrors should he use to see the objects?

• 2

• 3

• 4

• 1