Unit 1 – Light and Sound
5.3 Light, Sound and
Electricity
Daily life sketches
1.
Based on the following situation, answer the questions.
A.
B.
Why does everything
appear smaller in the
mirror?
1) Is the mirror in front of the mother plane or convex? What are the characteristics of
the image formed by it?
2) Is the mirror at the corner of the wall of the boutique plane or convex? What are the
characteristics of the image formed by it?
3) Where in a boutique are the mirrors mentioned in Question 2 usually located?
Why?
Ans: 1) Plane. The image is of the same size as the object, and the image is laterally
inverted. 2) Convex. The image is smaller than the object. A convex mirror gives a
broader view than a plane mirror. 3) Corners, so that shopkeepers can monitor
customers to prevent shoplifting.
New General Studies
Q1
 Educational Publishing House Ltd 2016
Unit 1 – Light and Sound
5.3 Light, Sound and
Electricity
Daily life sketches
2.
Based on the following situation, answer the questions.
救護車
1) Why do the Chinese characters read differently to the driver and the boy?
2) Why are the Chinese characters of ‘Ambulance’ on the bonnet laterally inverted?
3) Is a rear-view mirror plane or convex? What are the characteristics of the image
formed by it?
Ans: 1) This is because the driver sees the word in a rear-view mirror, and the boy
reads the word written on the bonnet. 2) So that drivers can give way to an ambulance
immediately when they read the word in the correct form in the rear-view mirror.
3) Convex. The image is smaller than the object and laterally inverted. A convex mirror
gives a broader view than a plane mirror.
New General Studies
Q2
 Educational Publishing House Ltd 2016
Unit 1 – Light and Sound
5.3 Light, Sound and
Electricity
Daily life sketches
3.
Based on the following situation, answer the questions.
A.
B.
1) Can the girl hear the boy clearly in Picture A?
2) What should the boy do so that the girl can hear him through the cup?
3) In Picture B, what medium is sound transmitted through?
Ans: 1) No. 2) Straighten the string connecting the two cups. 3) e.g. Through solids. (or
any other reasonable answers)
.
New General Studies
Q3
 Educational Publishing House Ltd 2016
Unit 1 – Light and Sound
5.3 Light, Sound and
Electricity
Illustrated experiments
1.
Erect a plane mirror along the dotted line. Answer the questions based on the results of
the experiment.
1) Draw the image in the plane mirror on the graph paper.
2) Why is the image formed by a plane mirror clear? Circle the correct answer.
When light hits a plane mirror, (regular / irregular) reflection takes place.
3) When is it impossible to carry out this experiment? Circle the correct answer.
(When the object is inverted. / When there is no light.)
Ans: 1)
(the image is of the same size as the object and
is laterally inverted) 2) regular 3) When there is no light.
New General Studies
Q4
 Educational Publishing House Ltd 2016
Unit 1 – Light and Sound
5.3 Light, Sound and
Electricity
Integrated thinking
1.
Study the following pictures and answer the questions.
A.
B.
Mandy
Lily
1) In Picture A, can Mandy see the candle light? Why?
2) In Picture B, what does Lily do to form a shadow of her hand?
New General Studies
Q5
 Educational Publishing House Ltd 2016
Unit 1 – Light and Sound
5.3 Light, Sound and
Electricity
Integrated thinking
3) What phenomenon of light occurs when each of the following images are formed?
Circle the correct answer.
Plane mirror
Convex mirror
Magnifying
glass
Phenomenon of light
A.
Plane mirror
(Reflection / Refraction)
B.
Convex mirror
C.
Magnifying glass
(Reflection / Refraction)
(Reflection / Refraction)
4) According to the table above, how do the images formed in the three situations
differ? Complete the table.
Plane mirror
Convex mirror
Magnifying glass
A.
C.
E.
B.
D.
F.
Size
Lateral direction
New General Studies
Q6
 Educational Publishing House Ltd 2016
Unit 1 – Light and Sound
5.3 Light, Sound and
Electricity
Integrated thinking
5) What are the properties of light? Complete the following diagram.
Light
Light
Phenomenon / Experiment
We can see what
is on the other
side through a
straight plastic
tube.
Light passes
through glass but
not wood.
When light hits a
plane mirror,
regular reflection
takes place.
Properties
A.
B.
C.
Ans: 1) No. Since the three holes are not in a straight line, light cannot pass through.
2) She shines light from the torch on the wall. Since light cannot pass through her hand,
the area blocked by her hand becomes dark and a shadow is formed. 3) A. Reflection.
B. Reflection. C. Refraction. 4) A. Same as the object. B. Laterally inverted. C. Smaller
than the object. D. Laterally inverted. E. Bigger than the object. F. Same direction.
5) A. Light travels in straight lines. B. Light passes through transparent objects.
C. When light hits a flat surface, regular reflection takes place and a clear image is
formed.
New General Studies
Q7
 Educational Publishing House Ltd 2016