Teachoo Questions

Class 8
Chapter 16 Class 8 - Light

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## Part of the eye which controls the light entering is called

(a) iris

(b) cornea

(c) lens

(d) retina

Iris controls the amount of light entering the eye by adjusting the size of pupil.

So, (a) is correct

## 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

In a non-luminous object, light is reflected from other objects

So, (b) is correct

## Light is falling on surfaces  S 1   S 2 and  S 3 as shown in the figure.

Surfaces on which the angle of incidence is equal to the angle of reflection is/are

(a) Only S 1

(b) S 1 and S 2

(c) S 2 and S 3

(d) All the three surfaces

Laws of reflection are always followed, irrespective of the type of surface.

Hence, angle of incidence is equal to angle of reflection in all three cases.

So, (d) is correct

## 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

We know that

• Cones - They are sensitive to bright light.
• Rods - They are sensitive to dim light

So, (b) is correct

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

Iris is the part of the eye which gives color

## How many times is a ray of light reflected by two plane mirrors placed parallel and facing each other?

Since the two mirrors are parallel,

the ray of light is reflected infinite number of times

## Which of the following works on the concept of multiple reflections?

1. Telescope
2. Binoculars
3. Kaleidoscope
4. Sunglasses