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Grade 8 Light and Optics Unit Review

Total questions: 79

Worksheet time: 2hrs 28mins

Name
Class
Date
1.
A student placed a pencil in a cup of water.  The pencil appears broken because light-
a)
always travels in a straight line
b)
bends when it passes through water
c)
makes the water in the glass evaporate
d)
reflects the pencil on the water's surface
2.
a)
Reflection
b)
Refraction
3.

Which lens represents the path light takes through a diverging lens?

a)
b)
c)
d)
4.

Which figure represents the path light takes through a converging lens?

a)
b)
c)
d)
5.

Which optical device bends light inward?

a)

convex lens

b)

concave lens

c)

plane mirror

d)

convex mirror

6.

A lens that is thicker in the middle than on the outside is called ___.

a)

diverging

b)

concave

c)

convex

d)

achromatic

7.

A lens that is thinner in the middle than on the outside is called ___.

a)

diverging

b)

concave

c)

convex

d)

achromatic

8.

Which technology CAPTURES and MAGNIFIES light?

a)

Telescope

b)

Microscope

c)

Camera

d)

All of them

9.

Which optical technology do we use to observe small things?

a)

Telescope

b)

Microscope

c)

Camera

d)

ALL of them

10.

Which technology do we use to observe FARAWAY objects?

a)

Telescope

b)

Microscope

c)

Camera

d)

All of them

11.

Which technology focuses light onto film/sensor so it can create a picture?

a)

Telescope

b)

Microscope

c)

Camera

d)

All of them

12.

What do all optical technologies need?

a)

Light

b)

Something to focus

c)

A machine

d)

A magnifying glass

13.
Which part of the eye opens in dark places and closes in bright places?  
a)
Cornea
b)
Retina
c)
Pupil
d)
Lens
14.
Which part of the eye is where images are converted to nerve impulses?  
a)
Retina
b)
Cornea
c)
Optic Nerve
d)
Lens
15.
Regulates the amount of light entering the eye and gives the eye its color.
a)
Iris
b)
Lens
c)
Pupil
d)
Retina
16.
True
a)
Cone cells detect light and dark
b)
Rods focus light
c)
Cones detect color
d)
Rods detect color
17.

Which statement is true?

a)

Rods detect light.

b)

Rods detect colour.

c)

Rods are the material which colours the eye.

d)

All of the above

18.

Pixel stands for

a)

image dot

b)

picture element

c)

image element

d)

none of the above

19.
What is this?
a)
Opaque
b)
transparent
c)
translucent
20.
What is this
a)
opaque
b)
transparent
c)
translucent
21.
The water is what
a)
opaque
b)
translucent
c)
transparent
22.

We see objects because light is reflected off of them.

a)

True

b)

False

23.

Which of the following is NOT a true statement about light?

a)

Light can be absorbed.

b)

Light can be abstracted.

c)

Light can be bent.

d)

Light can be reflected.

24.

Light changes _____________ as it moves from air to water.

a)

its mind

b)

direction

c)

color

d)

focus

25.

Your eyes are ____________ lenses.

a)

convex

b)

concave

c)

contact

d)

all of the above

26.

Light is a form of ___________ that travel in a straight line.

a)

energy

b)

resources

27.

which type of lens will help correct this vision problem

a)

convex

b)

concave

c)

opaque

d)

plano

28.

The angle of incidence is equal to the angle of reflection

a)

Law of Reflection

b)

Law of Light

c)

Incidence Ray

d)

The Normal

29.
Opaque means...
a)
No light passes through it
b)
All light passes through it
c)
Some light passes through it
30.

This is an example of

a)

Refraction.

b)

Transparent

c)

Opaque

d)

None.

31.
How does light energy move?
a)

In a straight line

b)
In different directions
32.

What is the law of reflection?

a)

The angle of incidence is greater than the angle of reflection.

b)

The angle of reflection is perpendicular to the angle of incidence.

c)

The angle of reflection is less than the angle of incidence.

d)

The angle of incidence is equal to the angle of reflection.

33.

A beam of light drawn as straight lines with arrows

a)

Incidence Ray

b)

Reflected Ray

c)

X-ray

d)

Ray

34.

The picture shows which type of reflection?

a)

Specular

b)

X-ray

c)

Diffuse

d)

Normal

35.

The ray of light that strikes a mirror

a)

Reflected Ray

b)

Incidence Ray

c)

Angle of Incidence

d)

Angle of Reflection

36.

The ray that bounces off the mirror.

a)

Angle of Reflection

b)

Incidience Ray

c)

Reflected Ray

d)

Angle of Reflection

37.

The angle between the incident ray and the normal. (X on the diagram)

a)

Angle of X-Ray

b)

Angle of Reflection

c)

Angle of Incidence

d)

Angle of Normal

38.

The angle between the reflected ray and the normal (labelled Y on the diagram).

a)

Angle of Incidence

b)

Angle of Reflection

c)

Angle of Normal

d)

Angle of Light

39.

An imaginary line that is drawn at a right angle (90 degrees) to a mirror (Green line)

a)

Reflection Ray

b)

Normal

c)

Incidence Ray

d)

Light Ray

40.

If the angle of incidence in the diagram is 80°, the angle of reflection will be:

a)

10°

b)

100°

c)

90°

d)

80°

41.

True or False: This diagram shows the correct position of the mirrors so that the light hits the target

a)

True

b)

False

42.

Which of the following concepts is associated with Sir Isaac Newton?

a)

Sight occurred when light beams from the eyes struck an object.

b)

Sight occurs when light bounces off an object to the eye.

c)

Light travels in straight lines, and the law of reflection.

d)

White light is a mixture of colors.

43.

The best explanation for shadows is

a)

black light is projected onto an object

b)

light bends only part way round solid objects

c)

when light hits an opaque object, it cannot go any further

d)

when light strikes an object, the object projects a black light

44.

Lin’s theatre group wants to create a dark and gloomy forest scene. They cut out a silhouette of trees from thick, black paper and hold it in front of a stage light to create a shadowy effect. The problem is the shadow cast on the backdrop is too small. What could they do to increase the size of the shadow?

a)

Move the light away from the paper cutout.

b)

Move the paper cutout closer to the curtain.

c)

Move the paper cutout closer to the light.

d)

Trim the paper cutout to a smaller size.

45.
Where might you find a concave mirror?
a)
car headlights
b)
the corner of a convenience store
c)
inside a microscope
d)
in your eyeball
46.
Where might you find a convex mirror?
a)
car headlights
b)
the corner of a convenience store
c)
inside a microscope
d)
in your eyeball
47.
Where might you find a convex lens?
a)
car headlights
b)
the corner of a convenience store
c)
inside a microscope
d)
in your eyeball
48.
The part of the eye that is covered with rods and cones is the
a)
cornea
b)
iris
c)
vitreous humour
d)
retina
49.

The primary colors of light are

a)

red, green, indigo

b)

red, green, blue

c)

black, white, yellow

d)

magenta, cyan, yellow

50.

What causes the light to refract as it passes from air to water?

a)

a change in temperature of the light

b)

a change in illumination of the light

c)

a change in speed of the light

d)

a change in brightness of the light

51.

#1 Refers to the clear tissue that covers the front of the eye

a)

Retina

b)

Cornea

c)

Pupil

d)

Iris

52.

# 5 refers to the layer of receptor cells at the back of the eye in which the image is focused

a)

Retina

b)

Lens

c)

Optic Nerve

d)

Lens

53.

#3 Refers to the circular structure that surrounds the pupil and regulates the amount of light entering the eye.

a)

Cornea

b)

Pupil

c)

Retina

d)

Iris

54.

#2 refers to

a)

optic nerve

b)

cornea

c)

iris

d)

pupil

55.

Which type of vision allows you to see distance clearly but nearby objects appear blurry?

a)

farsighted

b)

nearsighted

56.

Which cells distinguish between black, white and shades of gray?

a)

Cones

b)

Rods

c)

Optic Nerves

d)

Iris

57.

What do you call the spot where there is a lack of cones and rods, where the optic nerve begins at the back of the eye?

a)

Optical Nerve entrance

b)

Optical Divide

c)

Blackspot

d)

Blindspot

58.

Which of the following would result in a larger shadow to be cast on the screen?

a)

Move the screen nearer the object.

b)

Move the object closer to the screen.

c)

Move the light source nearer the object.

d)

Move the light source away from the object.

59.

Given that the angle of incidence = 30 degrees


Which is the correct diagam?

a)

A

b)

B

c)

C

d)

D

60.

If you were using a plane mirror to help put in an earring, which of the following statements would be true?

a)

Your image appears larger and inverted.

b)

Your image appears smaller and inverted vertically.

c)

Your image is the same size and upright

d)

Your image is the same size and inverted vertically.

61.

What occurs to light rays after they hit a convex mirror?

a)

They converge

b)

They diverge

c)

They reflect at right angles.

d)

They are absorbed.

62.

Light travels fastest through which of the following materials?

a)

Diamond

b)

Glass

c)

Water

d)

Air

63.

On the diagram, E is:

a)

The angle of incidence

b)

The normal

c)

The angle of reflection

d)

The angle of refraction

64.

In the ray diagram below, which angle represents the refracted angle?

a)

A

b)

B

c)

C

65.

Based on the diagram, which is statement is correct?

a)

P and Q are media with different densities

b)

P and Q shares equal densities

c)

Q is denser than P

d)

P is denser than Q

66.

If medium Q is more optically dense than medium P, which of the following is a possible refracted ray?

a)

A

b)

B

c)

C

d)

D

67.
What is the order of the path of light in the human eye?
a)
cornea, pupil, lens, retina, optic nerve, brain
b)
 lens,cornea, pupil, retina, optic nerve, brain
c)
pupil, lens, retina, optic nerve, cornea, brain
d)
brain, pupil, lens, retina, optic nerve, cornea,
68.
For clear vision, an image must be focused exactly on the ________________.
a)
retina
b)
pupil
c)
optic nerve
d)
lens
69.

Which one of the following is true both for human eye and digital camera?

a)

the sensor detects light.

b)

the aperture controls the amount of light that enters.

c)

the lens focuses the light.

70.

What is the responding variable in this experiment?

a)

distance between lens and eraser

b)

length of eraser

c)

type of lens in visualizer

d)

length of image

71.
A CCD is in a ...
a)
digital camera
b)
telescope
c)
microscope
d)
compound eye
72.
Insects have ...
a)
compound eyes
b)
camera eyes
73.
An ommatidium is a small part of a ...
a)
camera eye
b)
compound eye
c)
digital image
d)
telescope
74.
What is the effect of increasing the resolution of an image?
a)
The image has more white
b)
The image gets bigger
c)
The image quality improves
d)
The image gets smaller
75.
More pixels in an image produces ____ resolution.
a)
higher
b)
lower
76.
The camera’s aperture controls 
a)
the opening and closing of the lens
b)
amount of light entering a camera
c)
the recording of the image
d)
focusing of the image
77.

Why does your pupil increase in size when you enter a dark room?

a)

To protect the eye

b)

to allow more light to enter the eye

c)

to allow less light to enter the eye

d)

to creep people out

78.
A characteristic of fish eyes is...
a)
a rigid lens
b)
a round lens
c)
5 cone types
d)
tapetum lucidum
79.
A characteristic of cat eyes is...
a)
a rigid lens
b)
a round lens
c)
5 cone types
d)
tapetum lucidum