Question 1

(a) Match a word in column A with a line in column B.

Light Which cannot be projected on a screen

Beam A luminous object

Reflection Collection of rays

Virtual Bouncing off of light from a surface

Sun Form of energy

(b) Fill in the blanks in the following

(i)

(ii) The first law of reflection states that the angle of incidence i is …………… to the angle

of reflection r.

(iii) The normal is an imaginary line which is ………………….. to the surface of the mirror.

(iv) The point O in the diagram is called the point of ………………………….

Worksheet Light Grade 9

Page 1

(c) State the value of the angle of reflection ‘r ‘ for each of the following

(i)

r = ……………

(ii)

r = ……………

(iii)

r = ………………….

(d) Consider the diagram below of a person looking at himself in the mirror.

(i) A, B, C and D are points on the person’s body. Which is the lowest point he can see?

………………………………………………………………………………………………………

(ii) Which part of his body he cannot see in the mirror, AB or BC or CD?

…………………………………………………………………………………………………….

Worksheet Light Grade 9

Page 2

The figure below shows the image of the alphabet F formed by a plane mirror.

Using the figure above, answer the following questions:

Using a ruler, measure and compare XY with X’Y’ and YZ with Y’Z’.

Complete the statement: The image size is the ……………as the object size.

Measure distance X from the mirror = …………………….. cm

Measure distance X’ from the mirror = ………………………. Cm

Complete the statement: The image distance is the …………………as the object

distance.

Tick the appropriate box(es) that corresponds to the characteristics of and image.

☐ The image is upside down

☐ The image is laterally inverted

☐ The image is enlarged

☐ The image is upright

Question 2

Worksheet Light Grade 9

Page 3

Question 1b.

The diagram shows a plane mirror. On the diagram label the following:

(a) incident ray

(b) point of incidence M

(c) normal NM

(d) the angle of incidence i

(e) the reflected ray

(f) the angle of reflection r

(g) the object O

(h) the image I

(i) the object distance

(j) the image distance

(k) the virtual ray

plane

mirror

Question 3

Worksheet Light Grade 9

Page 4

Question 4:A man stands in front of a vertical plane mirror which is fixed on a wall as shown in the diagram below. The image formed by the mirror is also shown.

(a) The man looks at the image of his feet.

(i) Complete the ray diagram to show how the man is able to see the image of his feet in the mirror.

(ii) What is the purpose of the normal line in the diagram in the previous page?

………………………………………………………………………………….............................

(iii) State which angle does x represent.

…………………………………………………………………...……………………………..…

(iv) Measure angle x.

Angle x = ………………...

(b) Show on the diagram above, by means of bracket ( } ), the part of the plane mirror which is not usedby the man when he sees his full image.

xNormal

Plane mirror Wall

Image

Worksheet Light Grade 9

Page 5

Question 4

(a) The figure below shows the image of a polar bear formed by reflection from a water surface.

(i) Suggest why the image is blurred

………………………………………………………………………………………………………………

………………………………………………………………………………………………………………

Question 5

Worksheet Light Grade 9

Page 6

(ii) State two characteristics of an image formed by reflection

1. ___________________________________________________________________________________

2. ___________________________________________________________________________________

(b) Fill in the blanks.

(i) The first law of refraction states that the incident ray, the __________________ ray, and the

______________ line lie on the same __________________.

(ii) The second law of refraction states that the ratio of the sine of the angle of __________________ to

the ________________ of the angle of refraction is __________________.

(i) State what is meant by “normal line”

………………………………………………………………………………………………………………

………………………………………………………………………………………………………………

Worksheet Light Grade 9

Page 7

(ii) State the value of the angle of incidence of the ray of light through block A.

Angle of incidence =…………………

(iii) On Fig 4.1, use a ruler to draw the path of the ray of light passing through Block A and emerging into air.

(iv) Measure the angle of incidence for the ray of light in block B.

Angle of incidence =…………………

(v) Sketch the path of the light ray inside Block B and emerging into air.

Worksheet Light Grade 9

Page 8