S.3 Physics Exercise 5 – Light, colours and beyond
Name : _______________________ (
)
A True or false questions
Write ‘T’ for a true statement and ‘F’ for a false statement in the boxes provided.
1
2
3
Gamma rays can be used to kill cancer cells deep inside human bodies.
It is proven that radio waves are not harmful to humans.
Gamma rays can only pass through a few solids.
4
5
X-rays have the highest frequencies in the electromagnetic spectrum.
All electromagnetic waves travel at the same speed in a vacuum.
B Multiple-choice questions
Choose the correct answer for each of the following questions.
1
2
3
Which of the following statements about microwaves is INCORRECT?
A
Microwaves can be regarded as high-frequency radio waves.
B
Microwaves can be used in cooking.
C
Microwaves can be used in detecting the position of a ship.
D
Microwaves cannot pass through the atmosphere.
Which of the following correctly arranges the electromagnetic waves in
descending order of frequency?
A
B
C
Ultra-violet radiation, X-rays, visible light
Ultra-violet radiation, visible light, X-rays
X-rays, ultra-violet radiation, visible light
D
Visible light, ultra-violet radiation, X-rays
Which of the following statements about gamma rays and ultra-violet
radiation are correct?
(1) Gamma rays travel faster than ultra-violet radiation in a vacuum.
(2) Both can be used in sterilization.
(3) Both are invisible to humans.
A
(1) and (2) only
B
C
D
(1) and (3) only
(2) and (3) only
(1), (2) and (3)
4
The table below shows the typical frequencies of some parts of the
electromagnetic spectrum.
Radiation
Infra-red radiation
12
10
Frequency (Hz)
X
16
10
Y
10
7
Z
1010
Which of the following is an application of radiation Z?
A
B
C
D
5
Remote control
Radar
Detecting fake banknotes
Examining luggage
In airports, what kinds of electromagnetic waves are used to check the
luggage and body temperature of travellers respectively?
Luggage
Body temperature
A
B
C
D
X-rays
Gamma rays
X-rays
Gamma rays
Ultra-violet radiation
Ultra-violet radiation
Infra-red radiation
Infra-red radiation
C Fill in the blanks
Complete the following sentences.
1
Octopus cards make use of ___________________________, which are a part of the
electromagnetic spectrum with the ________________ frequency.
2
Water strongly absorbs electromagnetic waves of certain frequencies. This principle is used in
___________________________ to cook food.
3
The ________________________________ is a system that can tell our accurate location on
Earth. It is widely used in cars to aid navigation.
D Questions
1
The right photo shows an image of a patient’s knee. It is taken by using
a kind of electromagnetic waves.
a
What kind of electromagnetic waves is used to take this photo? (1
mark)
_________________________________________
*b
Why does the doctor need to stay in another room when the photo
is being taken?
(2 marks)
steel
screw
_________________________________________
_________________________________________
*c
The photo also shows a steel screw fixed in the patient’s knee. Compare the abilities of
muscles, bones and steel in blocking the waves.
(2 marks)
___________________ > __________________ > __________________
d
Suggest another application of this kind of electromagnetic waves. (1 mark)
_____________________________________________________________
2
As shown in the diagram on the right, Susan repeatedly rubs the
clip on the metal file.
a
What does Susan observe when she rubs the clip on the
metal file?
(1 mark)
clip
metal file
____________________________________
____________________________________
b
What kind of electromagnetic waves is produced?
(1 mark)
_____________________________________________________________
c
Name TWO applications of this kind of electromagnetic waves.
(2 marks)
_____________________________________________________________
– End –
A True or false questions
1 T
2 F
3 F
4 F
5 T
B Multiple-choice questions
1 C
2 C
3 C
4 B
5 C
C
1
2
3
Fill in the blanks
radio waves; lowest
microwave ovens
Global Positioning System
D
1
Questions
a X-rays.
b To avoid absorbing X-rays,
which are harmful to humans.
c
d
2
a
b
c
Steel > bones > muscles
Detecting dangerous objects carried by travellers and in luggage
at airports.
1m
1m
1m
2m
1m
Sparks appear at the contact point between the clip and the metal file. 1 m
Radio waves.
1m
Octopus cards and
1m
radio broadcasting.
1m
0
