Angle of incidence is equal to the angle of reflection

1

(a)

Always

(b)

Sometimes

(c)

Under special conditions

(d)

Never

As the angle between two plane mirrors is decreasing gradually, the number of images of an object placed between them

1

(a)

first increases then decreases

(b)

first decreases then increases

(c)

increases

(d)

decreases

How does the eye change in order to focus on near or distant objects?

1

(a)

The eye lens moves in or out

(b)

The retina moves in or out

(c)

The eye lens becomes thicker or thinner

(d)

The pupil becomes larger or smaller

The change in converging power of an eye lensis caused by the action of

1

(a)

retina

(b)

optic nerve

(c)

ciliary muscles

(d)

iris

Which of the following statements is correct regarding rods and cones in the human eye?

1

(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

The size of the pupil becomes ____________ when you see in dim light.

1

(a)

large

The image of an object persists on the retina of an eye for about _______ second even after the object has disappeared.

1

(a)

1/16

If the still pictures of a moving object are flashed on our eyes at a rate faster than _________ pictures per second, the eye perceives the object as moving.

1

(a)

16

In a movie, the still pictures in proper sequence are projected on the screen usually at the rate of ___________ pictures per second.

1

(a)

24

The muscles attached to the eye lens make it thicker to see _________ objects.

1

(a)

Under special conditions

Diffused/Irregular reflection takes place from rough surfaces.

1

(a) False

(b) True

Sunlight, called white light consists of seven colours.

1

(a) False

(b) True

Visually challenged people can read and write with hearing aid.

1

(a) True

(b) False

An eye lens focuses light behind the eye at cornea.

1

(a) True

(b) False

The part of the eye that renders colour to it is cornea.

1

(a) True

(b) False

State the function of eyelids.

2

(a)

Mention for how much duration, image stays on retina.

2

(a)

Why are we able to see the tap water in the glass even though it is colourless?

2

(a)

Black objects appear black. Why?

2

(a)

White light is a combination of which colours?

2

(a)

Gurmit wanted to perform Activity using a laser torch. Her teacher advised her not to do so. Can you explain the basis of the teacher’s advise?

3

(a)

Explain how you can take care of your eyes.

3

(a)

(a) Find out the position of the image of an object situated at A in the plane mirror.
(b) Can Paheli at B see this image?
(c) Can Boojho at C see this image?
(d) When Paheli moves from B to C, where does the image of A move?

3

(a)

Explain in brief, how do ciliary muscles affect the functioning of eye.

3

(a)

Draw figure showing the position of the plane mirror. Also, label the angle of incidence and angle of reflection on it.

3

(a)

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

(a) Mention how many mirrors should he use to see the objects.
(b) Indicate the positions of the mirrors in the figure.
(c) State what must be the angle w.r.t. the incident light at which he should place the mirrors.
(d) Indicate the direction of rays in the figure.
(e) If any of the mirrors is removed, will he be able to see the objects?

5

(a)

How is the phenomenon of reflection used in making a kaleidoscope? What are the applications of a kaleidoscope?

5

(a)