Learner GuideCambridge O LevelPhysics
5054
Cambridge Secondary 2
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© Cambridge International Examinations 2015
Version 2
Contents
How to use this guide ....................................................................................................... 3Section 1: How will you be tested?Section 2: Examination adviceSection 3: What will be tested?Section 4: What you need to knowSection 5: Useful websitesSection 6: Appendices
Section 1: How will you be tested? ..................................................................................... 5About the papersAbout the theory papersAbout the practical papers
Section 2: Examination advice ............................................................................................. 9General advice
Section 3: What will be tested? ......................................................................................... 13
Section 4: What you need to know ................................................................................... 15How to use the table
Section 5: Useful websites ...............................................................................................43
Section 6: Appendices .....................................................................................................45Symbols, units and defi nitions of physical quantitiesCommand words and phrases
2 Cambridge O Level Physics 5054
How to use this guide
3 Cambridge O Level Physics 5054
How to use this guide
The guide describes what you need to know about your Cambridge O Level Physics examination.
It will help you to plan your revision programme for the written examinations and will explain what we are looking for in the answers you write. It can also be used to help you to revise by using the tick boxes in Section 4 ‘What you need to know’, to check what you know and which topic areas of physics you have covered.
The guide contains the following sections:
Section 1: How will you be tested?This section will give you information about the theory and practical examination papers.
Section 2: Examination adviceThis section gives you advice to help you do as well as you can. Some of the ideas are general advice and some are based on the common mistakes that candidates make in exams.
Section 3: What will be tested?This section describes the areas of knowledge, understanding and skills that we will test you on. It is particularly important to realise that most marks are awarded for understanding and skills and only approximately 30% of the total mark is for simple recall.
Section 4: What you need to knowThis shows the syllabus content so that you can check:
• which topics you need to know about
• details about each topic area in the syllabus
• how much of the syllabus you have covered.
Section 5: Useful websites• some useful websites that you might use.
Section 6: AppendicesThis section covers other things you need to know, such as:
• symbols, units and defi nitions of physical quantities
• the importance of the command words we use in examination papers.
How to use this guide
4 Cambridge O Level Physics 5054
Before you start:Check with your teacher which practical paper you will be taking (Paper 3 or Paper 4).
Both of these papers are described in Section 1 and Section 3. You only need to read about one of them.
The theory papers are the same for everyone and the theory is detailed in Section 2.
Section 1: How will you be tested?
5 Cambridge O Level Physics 5054
Section 1: How will you be tested?
About the papersYou will be entered for three examination papers: two theory papers and one practical paper. You will take Paper 1 Multiple Choice, Paper 2 Theory and either Paper 3 Practical Test or Paper 4 Alternative to Practical.
You need to ask your teacher which practical paper you are taking.
About the theory papersThe table gives you information about the theory papers.
Paper number and type
How long and how many marks?
What’s in the paper? What’s the % of the total
examination?
Paper 1Multiple Choice
1 hour(40 marks)
40 multiple-choice questions 27.6
Paper 2Theory
1¾ hours(75 marks)
Short answer and structured questions 51.7
Here is some more information about each paper.
Paper 1 Multiple ChoiceYou have to choose one of the four possible answers in each question.
The multiple-choice questions cover the entire syllabus, apart from Section 25 on Electronic Systems.
Paper 2 TheoryAll answers are written in the spaces provided on the actual question paper.
There are two sections.
Section A contains short structured questions where you may have to write a few words or sentences or make a calculation. You must answer all the questions.
Section B has three longer questions. Each question is worth 15 marks. You must answer two of the three questions, so take your time to read them carefully before choosing which questions to answer.
Questions on Section 25 (Electronic Systems) will always be optional.
Section 1: How will you be tested?
6 Cambridge O Level Physics 5054
About the practical papersJust over 20 per cent of the marks for Cambridge O Level Physics are for practical work.
You will do one of the practical papers shown in the table, either Paper 3 or Paper 4. Your teacher will tell you which practical paper you will do.
Paper number and type How long and how many marks?
What’s invovled?
Paper 3Practical Test
2 hours(30 marks)
You do a practical exam which is supervised by a teacher
Paper 4Alternative to Practical
1 hour(30 marks)
You answer a written paper about practical work.
Here is some more detail about the practical papers. If you are unsure of anything, ask your teacher.
EITHER
Paper 3 Practical TestYou do a practical exam, which is supervised by a teacher. You will carry out four short experiments.
Section A contains three short questions and lasts 1 hour. Section B contains one question that takes 1 hour.
You are given instructions, which enable you to carry out the experiments. You will take readings and record them in a table. You need to use a sensible number of fi gures and give the unit in the heading. You will usually draw a graph and make some conclusions, commenting upon accuracy and on how to improve the experiment.
You may be asked to use the following techniques, amongst others:
• recording current and potential difference and drawing circuit diagrams
• ray tracing and drawing ray diagrams
• measuring temperature
• balancing (centre of mass and moments)
• stretching of springs
• timing of oscillations.
Your experience of practical work during the course should enable you to handle the apparatus. Your teacher will be able to give you more examples and explain how to take readings and analyse the data.
OR
Section 1: How will you be tested?
7 Cambridge O Level Physics 5054
Paper 4 Alternative to PracticalThis is a written paper, testing the same skills as Paper 3. There are usually four questions which test practical procedures in the physics laboratory.
You may be asked to:
• record readings from diagrams of apparatus, e.g. reading current from an ammeter
• answer questions on the arrangement of apparatus
• complete tables of data
• draw conclusions from information
• answer questions about experimental data
• plot a graph from a table of readings
• interpret information from graphs
• draw ray diagrams
• identify sources of error and suggest improvements in the experiment
• suggest suitable apparatus for investigations.
You will need to do plenty of practical work during the course in order to score a good mark on this paper in the examination.
Section 1: How will you be tested?
8 Cambridge O Level Physics 5054
Section 2: Examination advice
9 Cambridge O Level Physics 5054
Section 2: Examination advice
This section highlights some common mistakes made by candidates. They are collected under various subheadings to help you when you revise a particular topic.
General advice• Thorough and careful revision is the best way to prepare for a physics examination.
• Make your revision productive by making it interesting and fun. Make notes, revision cards or mind maps. Revision should be an active process, i.e. you should be ‘doing things’, not just sitting and reading a book.
• Don’t try to learn it all in one go! Take regular breaks and review what you have learnt regularly.
• Learning equations is essential; put them on small pieces of paper and stick them somewhere you will see them every morning.
• Revise with a friend so you can test each other or try explaining the physics of a topic to a friend – as if you were a teacher!
• Working through past paper questions is the best way to complete your revision. This helps you to know the type and style of questions to expect in the examination.
• Try timed questions so you can learn to answer quickly.
• Get your answers checked so you know you are correct!
• In Cambridge O Level Physics examinations you have to be able to complete a variety of tasks; always read the question carefully to make sure you have understood what you are expected to do.
Spelling• The spelling of technical terms is important, so make sure your writing is legible as well as spelt
correctly.
• Some words are very similar, such as refl ection and refraction, fi ssion and fusion. If we cannot tell which one you have written, then you will lose the mark. Make a list of technical terms and defi nitions in each section of the syllabus, checking the spellings carefully.
Descriptive answersIn descriptive answers, you should:
• Check the number of marks available and make sure you give suffi cient points.
• Plan your answer fi rst so that you don’t repeat yourself or contradict yourself.
• Read your answer through carefully afterwards to check you have not missed out important words.
• Read the question again to check you have answered the question asked.
• Use sketches and diagrams wherever you can to help your explanation.
• Add labels when referring to a diagram, e.g. point X, so that you can refer to it easily in your explanation. This can save many words and much confusion.
Section 2: Examination advice
10 Cambridge O Level Physics 5054
Numerical answersIn numerical answers, you should:
• Quote any formulae you are going to use and show clearly all the steps in your working. It may be tempting to use your calculator and just write down the answer, but if you write down one fi gure wrongly then you may lose all the marks for the calculation. If we can see the formula and the numbers you have used then you will lose only a little credit. Some questions ask for a formula to be quoted; even if you get the right answer, failure to quote the formula will lose you a mark.
• Check the units are consistent, e.g. if the distance is given in km and the speed in m/s, then you must convert the km to m.
• Be careful when you are converting minutes and seconds: 1 minute 30 seconds is not 1.3 minutes and 150 seconds is not 1.5 minutes. These are common mistakes, so always double check any conversion of units of time.
• State the answer clearly at the end.
• Give your answer as a decimal to an appropriate number of signifi cant fi gures. Don’t leave your answer as a fraction unless specifi cally asked to do so.
• Check that you have given the unit of your fi nal answer.
• Look at your fi nal answer and see that it is reasonable. If you have calculated the cost of using an electrical appliance such as a kettle for a few minutes and found it to be hundreds of dollars, then check the powers of ten in your calculation.
GraphsPlotting graphs can be tested in Papers 2, 3 or 4.
When drawing graphs, you should:
• Remember to label the axes with both quantity (e.g. distance or d) and unit (e.g. metres or m). Then write it as distance/metres or even just d/m.
• Make sure the axes are the correct way round. You are usually told, for example, to plot distance on the x-axis, so make sure you know that x is the horizontal axis!
• Make the scales go up in sensible amounts, i.e. 0, 5, 10… or 0, 2, 4… but not 0, 3, 6… or 0, 7, 14…
• Make sure that the plotted points fi ll at least half the graph paper. This means if you can double the scale and still plot all the points then you should double the scale.
• Check if you have been told to start the scales from the origin. If not, then think carefully about where to start the axes.
• When you are told to start the axes from a certain point (e.g. x = 1, y = 20) you must do so. You will lose a mark if you use a different point (e.g. the origin).
• Use a sharp pencil to plot the points and draw the line.
• Plot the points carefully. It is best to use small neat crosses. Every point will be checked by the examiner, and you will lose the mark if any are wrongly plotted.
• Draw either a straight line or a smooth curve. In physics we never join the dots!
• Your line may not go through all the points – especially in the practical papers.
• Remember that a best fi t line (curve or straight) should have some points above and some points below the line.
Section 2: Examination advice
11 Cambridge O Level Physics 5054
When taking readings from a graph, you should:
• Draw a large triangle when measuring the gradient of a line. It must be at least half the length of the line. Top tip: draw a triangle the full size of the graph! It is best to show the numbers on the sides of the triangle when fi nding the gradient.
• Always use points on the line, not your plotted points, when calculating the gradient.
• Draw a tangent to fi nd the gradient of a curve. Make sure it is at the right place on the curve. Again, use a large triangle.
• Make sure you read the scales correctly when reading a value from a graph. It may be that they are in mA rather than A or km rather than m.
When describing the shape of a graph, remember that:
• directly proportional means a straight line through the origin. There are two ways to check if quantities are directly proportional:
– doubling one quantity will cause the other to double
– dividing one by the other will give the same result
i.e. if two quantities F and L are directly proportional then if you fi nd several values of F/L they should be the same
• if the straight line does not go through the origin, then it is just called a linear graph
• inverse relationship means increasing one quantity will cause the other to decrease
• if doubling one quantity causes the other to halve, then they are inversely proportional.This can also be checked by:
– multiplying the two quantities together will give the same result
i.e. if two quantities F and L are inversely proportional then if you fi nd several values of F × L they should be the same.
Section 2: Examination advice
12 Cambridge O Level Physics 5054
Section 3: What will be tested?
13 Cambridge O Level Physics 5054
Section 3: What will be tested?
We test you on three assessment objectives:
AO1 your knowledge (what you remember) and understanding (how you use what you know and apply it to unfamiliar situations)
AO2 how you handle information and solve problems
AO3 your experimental skills
The theory papers test AO1 and AO2.
You should note that approximately 65% of the marks are for AO1 and of these only about half of these are for simple recall.
The practical papers test AO3.
The table shows you the range of skills you should try to develop.
Assessment objective
What this means Whatyou need to be able to do
AO1Knowledge with understanding
remembering facts and applying these facts to new situations
• Use scientifi c ideas, facts and laws
• Know the meaning of scientifi c terms, e.g. centre of mass
• Know equations and defi nitions
• Use simple equations, e.g. speed = distance/time
• Know about apparatus and how it works
• Know about symbols, quantities (e.g. mass and weight) and units (e.g. kg and N)
AO2Handling information and solving problems
how you extract information and rearrange it in a sensible pattern and how you carry out calculations and make predictions
• Select and organise information from graphs,
• tables and written text
• Change information from one form to another, e.g. draw graphs
• Arrange data and carry out calculations
• Identify patterns from information given and draw conclusions
• Explain scientifi c relationships, e.g. use the moving (kinetic) particle theory to explain ideas about solids, liquids and gases
• Make predictions and develop scientifi c ideas
• Solve problems
Section 3: What will be tested?
14 Cambridge O Level Physics 5054
AO3Experimental skills and investigations
planning and carrying out experiments, recording and analysing information
• Follow instructions to set up and use apparatus safely
• Make observations and measurements and record them with regard to precision, accuracy and units
• Analyse experimental results
• Plan and carry out an experiment describing any problems and suggesting improvements
Section 4: What you need to know
15 Cambridge O Level Physics 5054
Section 4: What you need to know
The following table describes the things you may be tested on in the examination.
The main headings in the topic areas are usually followed by the details of what you need to know.
How to use the tableYou can use the table throughout your course to check the topic areas you have covered.
There is no need to start at the beginning. Use it when you fi nish a section of your course to make sure that you understand what you should be able to do.
When you think you have a good knowledge of a topic, you can tick the appropriate box in the checklist column.
Test yourself as follows:
• cover up the details with a piece of paper
• try to remember the details
• when you have remembered the details correctly, put a tick in the appropriate box.
You can also use it as a revision aid at the end of the course to fi nd out any weaknesses or areas you need to do some work on or ask your teacher about.
If you use a pencil to tick the boxes, you can retest yourself whenever you want by simply rubbing out the ticks. If you are using the table to check which topics you have covered, you can put a tick in the topic column, next to the appropriate bullet point.
The column headed ‘Comments’ can be used:
• to add further information about the details for each bullet point
• to add learning aids, e.g. simple equations set out in a triangle to help in rearranging the equation
• to show areas of diffi culty/things you need to ask your teacher about.
There are six major themes in the table:
General Physics
Newtonian Mechanics
Energy and Thermal Physics
Waves
Electricity and Magnetism
Atomic Physics.
Each theme contains a number of sections. The 27 sections cover the whole syllabus. Each section contains a number of topics and the table lists what you should be able to do in each topic.
Section 4: What you need to know
16 Cambridge O Level Physics 5054
You should note that questions on Section 25, Electronic Systems, only appear in Paper 2 and are always set as an alternative within a question.
Your teacher may have chosen not to cover this section in your course. In that case you should not need to learn that topic.
Do, however, make sure that you understand Section 24, Introductory Electronics.
Section 4: What you need to know
17 Cambridge O Level Physics 5054
Section 4: What you need to know
17
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
TH
EM
E 1
Gen
eral
Ph
ysic
s
1. P
hys
ical
qu
anti
ties
, un
its
and
mea
sure
men
ts
Sca
lars
and
vec
tors
• de
fi ne
the
term
s sc
alar
and
vec
tor
• fi n
d th
e re
sulta
nt o
f tw
o ve
ctor
s by
a g
raph
ical
met
hod
• kn
ow w
hich
of
the
follo
win
g ar
e sc
alar
s an
d w
hich
are
ve
ctor
s: d
ista
nce,
dis
plac
emen
t, le
ngth
, spe
ed, v
eloc
ity,
time,
acc
eler
atio
n, m
ass
and
forc
e
Mea
sure
men
t tec
hniq
ues
• de
scrib
e ho
w to
mea
sure
diff
eren
t le
ngth
s w
ith s
uita
ble
accu
racy
usi
ng t
apes
, rul
es, m
icro
met
ers,
and
cal
iper
s (t
he u
se o
f a
vern
ier
scal
e is
no
t re
quire
d)•
desc
ribe
how
to m
easu
re d
iffer
ent
time
inte
rval
s us
ing
cloc
ks a
nd s
topw
atch
es
Uni
ts a
nd s
ymbo
ls•
reco
gnis
e an
d us
e th
e S
I sys
tem
of
units
– y
our
teac
her
will
hav
e m
ore
info
rmat
ion
TH
EM
E 2
New
ton
ian
Mec
han
ics
2. K
inem
atic
s
Spe
ed, v
eloc
ity a
nd
acce
lera
tion
• st
ate
wha
t is
mea
nt b
y sp
eed
• st
ate
wha
t is
mea
nt b
y ve
loci
ty•
calc
ulat
e av
erag
e sp
eed
usin
g
aver
age
spee
d =
dis
tanc
e tr
avel
led/
time
take
n•
stat
e w
hat
is m
eant
by
unifo
rm a
ccel
erat
ion
• ca
lcul
ate
acce
lera
tion
usin
g
acce
lera
tion
= c
hang
e in
vel
ocity
/tim
e ta
ken
• ex
plai
n w
hat
is m
eant
by
non-
unifo
rm a
ccel
erat
ion
Section 4: What you need to know
18 Cambridge O Level Physics 5054
Section 4: What you need to know
18
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Gra
phic
al a
naly
sis
of
mot
ion
• pl
ot a
nd u
se d
ista
nce-
time
grap
hs.
• pl
ot a
nd u
se s
peed
-tim
e gr
aphs
.•
reco
gnis
e th
e sh
ape
of a
spe
ed-t
ime
grap
h fo
r a
body
:at
rest
, m
ovin
g w
ith u
nifo
rm s
peed
m
ovin
g w
ith u
nifo
rm a
ccel
erat
ion
mov
ing
with
non
-uni
form
acc
eler
atio
n•
calc
ulat
e th
e ar
ea u
nder
a s
peed
-tim
e gr
aph
to fi
nd t
he
dist
ance
tra
velle
d by
a b
ody
mov
ing
with
con
stan
t sp
eed
or c
onst
ant
acce
lera
tion
Free
-fal
l•
stat
e th
at t
he a
ccel
erat
ion
of f
ree-
fall
for
a bo
dy n
ear
to
the
Ear
th is
con
stan
t•
know
tha
t it
is a
bout
10
m/s
2
• de
scrib
e in
wor
ds t
he m
otio
n of
bod
ies
falli
ng w
ithou
t ai
r re
sist
ance
•
desc
ribe
in w
ords
the
mot
ion
of b
odie
s fa
lling
with
air
resi
stan
ce•
expl
ain
how
a b
ody
reac
hes
term
inal
vel
ocity
3. D
ynam
ics
Bal
ance
d an
d un
bala
nced
fo
rces
• st
ate
New
ton’
s th
ird la
w•
desc
ribe
the
effe
ct o
f ba
lanc
ed a
nd u
nbal
ance
d fo
rces
on
a b
ody
• de
scrib
e th
e w
ays
in w
hich
a fo
rce
may
cha
nge
the
mot
ion
of a
bod
y•
do c
alcu
latio
ns u
sing
the
equ
atio
n
forc
e =
mas
s ×
acc
eler
atio
n
Section 4: What you need to know
19 Cambridge O Level Physics 5054
Section 4: What you need to know
19
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Fric
tion
• ex
plai
n th
e ef
fect
s of
fric
tion
on t
he m
otio
n of
a b
ody
• de
scrib
e ho
w t
he fo
llow
ing
affe
ct f
rictio
n be
twee
n th
e w
heel
s of
a v
ehic
le a
nd t
he ro
ad:
tyre
sur
face
ro
ad c
ondi
tions
(inc
ludi
ng s
kidd
ing)
brak
ing
forc
e•
desc
ribe
how
the
se c
hang
e th
e:br
akin
g di
stan
ceth
inki
ng d
ista
nce
stop
ping
dis
tanc
e of
a v
ehic
le
Circ
ular
mot
ion
• de
scrib
e in
wor
ds h
ow o
bjec
ts m
ove
in a
circ
ular
pat
h du
e to
a c
onst
ant
forc
e pe
rpen
dicu
lar
to t
he d
irect
ion
of
trav
el•
appl
y id
eas
abou
t ci
rcul
ar m
otio
n to
:el
ectr
osta
tic fo
rces
on
an e
lect
ron
in a
n at
om,
grav
itatio
nal f
orce
s on
a s
atel
lite,
the
mot
ion
of p
lane
ts in
the
sol
ar s
yste
m
4. M
ass,
wei
gh
t an
d d
ensi
ty
Mas
s an
d w
eigh
t•
stat
e th
at m
ass
is a
mea
sure
of
the
amou
nt o
f su
bsta
nce
in a
bod
y•
stat
e th
at m
ass
of a
bod
y re
sist
s ch
ange
fro
m it
s st
ate
of
rest
or
mot
ion
• ca
lcul
ate
wei
ght
from
the
equ
atio
n
wei
ght =
mas
s ×
gra
vita
tiona
l fi e
ld s
treng
th•
expl
ain
that
wei
ghts
, and
the
refo
re m
asse
s, m
ay b
e co
mpa
red
usin
g a
bala
nce
• de
scrib
e ho
w to
mea
sure
mas
s an
d w
eigh
t by
usi
ng
suita
ble
bala
nces
Gra
vita
tiona
l fi e
lds
• st
ate
that
a g
ravi
tatio
nal fi
eld
is a
regi
on in
whi
ch a
mas
s ex
perie
nces
a fo
rce
due
to g
ravi
tatio
nal a
ttra
ctio
n
Section 4: What you need to know
20 Cambridge O Level Physics 5054
Section 4: What you need to know
20
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Den
sity
• de
scrib
e ho
w to
use
a m
easu
ring
cylin
der
to m
easu
re
the
volu
me
of a
liqu
id o
r so
lid.
• de
scrib
e ho
w to
det
erm
ine
the
dens
ity o
f:
a liq
uid
a re
gula
rly s
hape
d so
lidan
irre
gula
rly s
hape
d so
lid w
hich
sin
ks in
wat
er (v
olum
e by
dis
plac
emen
t)•
do c
alcu
latio
ns u
sing
the
equ
atio
n
dens
ity =
mas
s/vo
lum
e
5. T
urn
ing
eff
ect
of
forc
es
Mom
ents
• de
scrib
e th
e m
omen
t of
a fo
rce
in te
rms
of it
s tu
rnin
g ef
fect
• de
scrib
e si
mpl
e ev
eryd
ay e
xam
ples
of
mom
ents
• st
ate
the
prin
cipl
e of
mom
ents
for
a bo
dy in
equ
ilibr
ium
• do
cal
cula
tions
usi
ng
m
omen
t of a
forc
e =
forc
e ×
per
pend
icul
ar d
ista
nce
from
the
pivo
t•
do c
alcu
latio
ns u
sing
the
prin
cipl
e of
mom
ents
• de
scrib
e ho
w to
ver
ify t
he p
rinci
ple
of m
omen
ts
Cen
tre
of m
ass
• de
scrib
e ho
w to
fi nd
the
pos
ition
of
the
cent
re o
f m
ass
of a
pla
ne la
min
a
Sta
bilit
y•
desc
ribe
in w
ords
the
eff
ect
of t
he p
ositi
on o
f th
e ce
ntre
of
mas
s on
the
sta
bilit
y of
sim
ple
obje
cts
6. D
efo
rmat
ion
Elas
tic d
efor
mat
ion
• st
ate
that
a fo
rce
may
pro
duce
a c
hang
e in
siz
e an
d sh
ape
of a
bod
y•
plot
and
use
ext
ensi
on-lo
ad g
raph
s fo
r an
ela
stic
sol
id•
desc
ribe
an e
xper
imen
t to
mea
sure
the
ext
ensi
on
prod
uced
by
diff
eren
t lo
ads
for
an e
last
ic s
olid
• kn
ow w
hat
is m
eant
by
the
‘lim
it of
pro
port
iona
lity’
for
an e
last
ic s
olid
• ca
lcul
ate
exte
nsio
ns fo
r an
ela
stic
sol
id u
sing
ex
tens
ion
is d
irect
ly p
ropo
rtio
nal t
o lo
ad
Section 4: What you need to know
21 Cambridge O Level Physics 5054
Section 4: What you need to know
21
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
7. P
ress
ure
Pre
ssur
e•
defi n
e th
e te
rm p
ress
ure
in te
rms
of fo
rce
and
area
• do
cal
cula
tions
usi
ng t
he e
quat
ion
pr
essu
re =
forc
e/ar
ea•
expl
ain
how
pre
ssur
e va
ries
with
forc
e an
d ar
ea in
a
rang
e of
eve
ryda
y ex
ampl
es
Pre
ssur
e ch
ange
s•
desc
ribe
how
the
hei
ght
of a
liqu
id c
olum
n m
ay b
e us
ed
to m
easu
re t
he a
tmos
pher
ic p
ress
ure
• ex
plai
n in
wor
ds h
ow t
he p
ress
ure
bene
ath
a liq
uid
surf
ace
chan
ges
with
dep
th a
nd d
ensi
ty o
f th
e liq
uid
in
sim
ple
ever
yday
exa
mpl
es•
do c
alcu
latio
ns u
sing
the
equ
atio
n
pres
sure
= hρg
• de
scrib
e ho
w a
man
omet
er is
use
d to
mea
sure
pre
ssur
e di
ffer
ence
s•
desc
ribe
and
expl
ain
the
tran
smis
sion
of
pres
sure
in
hydr
aulic
sys
tem
s•
desc
ribe
the
wor
king
s of
:th
e hy
drau
lic p
ress
, hy
drau
lic b
rake
s on
veh
icle
s•
desc
ribe
how
cha
ngin
g th
e pr
essu
re a
pplie
d to
a g
as a
t co
nsta
nt te
mpe
ratu
re c
ause
s a
chan
ge in
vol
ume
• do
cal
cula
tions
usi
ng p
1V1 =
p2V
2
Section 4: What you need to know
22 Cambridge O Level Physics 5054
Section 4: What you need to know
22
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
TH
EM
E 3
En
erg
y an
d T
her
mal
Ph
ysic
s
8. E
ner
gy
sou
rces
an
d t
ran
sfer
of
ener
gy
Ener
gy fo
rms
• lis
t th
e di
ffer
ent
form
s of
ene
rgy
• gi
ve e
xam
ples
in w
hich
eac
h fo
rm o
ccur
s•
stat
e th
e pr
inci
ple
of t
he c
onse
rvat
ion
of e
nerg
y•
appl
y th
is p
rinci
ple
to t
he c
onve
rsio
n of
ene
rgy
from
one
fo
rm to
ano
ther
• st
ate
that
kin
etic
ene
rgy
Ek =
½ m
v2
• st
ate
that
pot
entia
l ene
rgy
EP =
mgh
• do
cal
cula
tions
usi
ng t
hese
equ
atio
ns
Maj
or s
ourc
es o
f en
ergy
• lis
t re
new
able
and
non
-ren
ewab
le e
nerg
y so
urce
s•
desc
ribe
the
ener
gy c
onve
rsio
ns t
akin
g pl
ace
whe
n us
ing
the
follo
win
g en
ergy
sou
rces
:–
chem
ical
/fue
l ene
rgy
(re-g
roup
ing
of a
tom
s)–
hydr
oele
ctric
gen
erat
ion
(em
phas
isin
g th
e m
echa
nica
l
ene
rgie
s in
volv
ed)
– so
lar
ener
gy (n
ucle
i of
atom
s in
the
Sun
)–
nucl
ear
ener
gy–
geot
herm
al e
nerg
y–
win
d en
ergy
• ex
plai
n ho
w n
ucle
ar f
usio
n re
leas
es e
nerg
y•
expl
ain
how
nuc
lear
fi ss
ion
rele
ases
ene
rgy
• de
scrib
e th
e ge
nera
tion
of e
lect
ricity
and
dra
w a
blo
ck
diag
ram
of
the
proc
ess
from
fue
l inp
ut to
ele
ctric
ity
outp
ut•
disc
uss
the
envi
ronm
enta
l iss
ues
asso
ciat
ed w
ith p
ower
ge
nera
tion
Wor
k•
calc
ulat
e w
ork
done
fro
m t
he e
quat
ion
w
ork
= fo
rce
× d
ista
nce
mov
ed in
dire
ctio
n of
the
forc
e
Section 4: What you need to know
23 Cambridge O Level Physics 5054
Section 4: What you need to know
23
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Effi c
ienc
y•
calc
ulat
e th
e ef
fi cie
ncy
of a
n en
ergy
con
vers
ion
usin
g th
e eq
uatio
n
effi
cien
cy =
ener
gy c
onve
rted
to th
e re
quire
d fo
rmto
tal e
nerg
y in
put
• di
scus
s th
e ef
fi cie
ncy
of e
nerg
y co
nver
sion
s in
com
mon
us
e, p
artic
ular
ly t
hose
giv
ing
elec
tric
al o
utpu
t•
disc
uss
the
usef
ulne
ss o
f en
ergy
out
put
from
a n
umbe
r of
ene
rgy
conv
ersi
ons
Pow
er•
calc
ulat
e po
wer
fro
m t
he e
quat
ion
po
wer
= w
ork
done
/tim
e ta
ken
9. T
ran
sfer
of
ther
mal
en
erg
y
Con
duct
ion
• de
scrib
e ho
w to
dis
tingu
ish
betw
een
good
and
bad
co
nduc
tors
of
heat
• de
scrib
e he
at t
rans
fer
in s
olid
s by
the
mov
emen
t of
m
olec
ules
• de
scrib
e he
at t
rans
fer
in s
olid
s by
the
mov
emen
t of
fre
e el
ectr
ons
Con
vect
ion
• de
scrib
e co
nvec
tion
in f
uids
usi
ng d
ensi
ty c
hang
es
Rad
iatio
n•
desc
ribe
how
hea
t is
tra
nsfe
rred
by
radi
atio
n•
desc
ribe
how
to d
istin
guis
h be
twee
n go
od a
nd b
ad
emitt
ers
of in
fra-
red
radi
atio
n•
desc
ribe
how
to d
istin
guis
h be
twee
n go
od a
nd b
ad
abso
rber
s of
infr
a-re
d ra
diat
ion
Tota
l tra
nsfe
r•
desc
ribe
how
hea
t is
tra
nsfe
rred
to o
r fr
om b
uild
ings
and
ro
oms
• st
ate
the
impo
rtan
t m
etho
ds o
f th
erm
al in
sula
tion
of
build
ings
• de
scrib
e ho
w t
hese
impo
rtan
t m
etho
ds in
sula
te t
he
build
ings
Section 4: What you need to know
24 Cambridge O Level Physics 5054
Section 4: What you need to know
24
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
10.
Tem
per
atu
re
Prin
cipl
es o
f th
erm
omet
ry•
expl
ain
how
a p
hysi
cal p
rope
rty
whi
ch v
arie
s w
ith
tem
pera
ture
may
be
used
for
the
mea
sure
men
t of
te
mpe
ratu
re•
stat
e ex
ampl
es o
f su
ch p
rope
rtie
s•
expl
ain
the
need
for
fi xed
poi
nts
• st
ate
wha
t is
mea
nt b
y th
e ic
e po
int
and
stea
m p
oint
• di
scus
s th
e fe
atur
es:
sens
itivi
tyra
nge
linea
rity
of t
herm
omet
ers
Pra
ctic
al t
herm
omet
ers
• de
scrib
e th
e st
ruct
ure
and
actio
n of
liqu
id-in
-gla
ss
ther
mom
eter
s (in
clud
ing
clin
ical
)•
desc
ribe
the
stru
ctur
e an
d ac
tion
of a
the
rmoc
oupl
e th
erm
omet
er•
expl
ain
the
use
of a
the
rmoc
oupl
e th
erm
omet
er fo
r m
easu
ring
high
tem
pera
ture
s an
d th
ose
whi
ch v
ary
rapi
dly
11.
Th
erm
al p
rop
erti
es o
f m
atte
r
Spe
cifi c
hea
t ca
paci
ty•
desc
ribe
a ris
e in
tem
pera
ture
of
a bo
dy a
s an
incr
ease
in
its in
tern
al e
nerg
y (r
ando
m t
herm
al e
nerg
y)•
defi n
e th
e te
rms
heat
cap
acity
•
defi n
e th
e te
rm s
peci
fi c h
eat
capa
city
• ca
lcul
ate
heat
tra
nsfe
rred
usi
ng t
he e
quat
ion
th
erm
al e
nerg
y =
mas
s ×
spe
cifi c
hea
t cap
acity
× c
hang
e in
tem
pera
ture
Section 4: What you need to know
25 Cambridge O Level Physics 5054
Section 4: What you need to know
25
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Mel
ting
and
boili
ng•
desc
ribe
mel
ting/
solid
ifi ca
tion
and
boili
ng/c
onde
nsat
ion
as a
tra
nsfe
r of
ene
rgy
with
out
a ch
ange
in te
mpe
ratu
re•
stat
e th
e m
eani
ng o
f m
eltin
g po
int
• st
ate
the
mea
ning
of
boili
ng p
oint
• ex
plai
n th
e di
ffer
ence
bet
wee
n bo
iling
and
eva
pora
tion
• de
fi ne
the
term
late
nt h
eat
• de
fi ne
the
term
spe
cifi c
late
nt h
eat
• ex
plai
n la
tent
hea
t by
writ
ing
abou
t m
olec
ules
• ca
lcul
ate
heat
tra
nsfe
rred
in a
cha
nge
of s
tate
usi
ng t
he
equa
tion
th
erm
al e
nerg
y =
mas
s ×
spe
cifi c
late
nt h
eat
Ther
mal
exp
ansi
on o
f so
lids,
liqu
ids
and
gase
s•
desc
ribe
in w
ords
the
the
rmal
exp
ansi
on o
f so
lids,
liqu
ids
and
gase
s•
desc
ribe
the
rela
tive
orde
r of
mag
nitu
de o
f th
e ex
pans
ion
of s
olid
s, li
quid
s an
d ga
ses
• lis
t an
d ex
plai
n so
me
of t
he e
very
day
appl
icat
ions
and
co
nseq
uenc
es o
f th
erm
al e
xpan
sion
• de
scrib
e in
wor
ds h
ow a
cha
nge
of te
mpe
ratu
re a
ffec
ts
the
volu
me
of a
gas
at
cons
tant
pre
ssur
e
12.
Kin
etic
mo
del
of
mat
ter
Sta
tes
of m
atte
r•
stat
e th
e pr
oper
ties
of s
olid
s, li
quid
s an
d ga
ses
Mol
ecul
ar m
odel
• de
scrib
e in
wor
ds t
he m
olec
ular
str
uctu
re o
f so
lids,
liq
uids
and
gas
es•
link
the
prop
ertie
s of
sol
ids,
liqu
ids
and
gase
s to
:th
e fo
rces
bet
wee
n th
e m
olec
ules
the
dist
ance
s be
twee
n m
olec
ules
the
mot
ion
of t
he m
olec
ules
• de
scrib
e ho
w c
hang
ing
the
tem
pera
ture
aff
ects
the
m
otio
n of
mol
ecul
es
• ex
plai
n th
e pr
essu
re o
f a
gas
in te
rms
of t
he m
otio
n of
its
mol
ecul
es
Section 4: What you need to know
26 Cambridge O Level Physics 5054
Section 4: What you need to know
26
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Eva
pora
tion
• de
scrib
e ev
apor
atio
n in
term
s of
the
esc
ape
of m
ore
ener
getic
mol
ecul
es f
rom
the
sur
face
of
a liq
uid
• de
scrib
e ho
w e
vapo
ratio
n is
aff
ecte
d by
:te
mpe
ratu
resu
rfac
e ar
eadr
augh
t ov
er t
he s
urfa
ce
• ex
plai
n th
at e
vapo
ratio
n ca
uses
coo
ling
TH
EM
E 4
Wav
es
13.
Gen
eral
wav
e p
rop
erti
es
Des
crib
ing
wav
e m
otio
n•
desc
ribe
wha
t is
mea
nt b
y a
wav
e m
otio
n•
desc
ribe
the
use
of:
rope
ssp
rings
rippl
e ta
nks
to d
emon
stra
te w
ave
mot
ions
Wav
e te
rms
• st
ate
wha
t is
mea
nt b
y a
wav
efro
nt•
defi n
e th
e te
rms:
spee
dfre
quen
cyw
avel
engt
h am
plitu
de
• do
cal
cula
tions
usi
ng
velo
city
= fr
eque
ncy
× w
avel
engt
h•
desc
ribe
a tr
ansv
erse
wav
e•
desc
ribe
a lo
ngitu
dina
l wav
e•
expl
ain
the
diff
eren
ces
betw
een
tran
sver
se a
nd
long
itudi
nal w
aves
Section 4: What you need to know
27 Cambridge O Level Physics 5054
Section 4: What you need to know
27
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Wav
e be
havi
our
• de
scrib
e ho
w a
rip
ple
tank
is u
sed
to s
how
:
–
refl e
ctio
n at
a p
lane
sur
face
– re
frac
tion
due
to a
cha
nge
of s
peed
• de
scrib
e si
mpl
e ex
perim
ents
to s
how
the
refl e
ctio
n of
so
und
wav
es•
desc
ribe
a si
mpl
e ex
perim
ent
to s
how
the
refr
actio
n of
so
und
wav
e
14.
Lig
ht
Refl
ect
ion
of li
ght
• de
fi ne
the
follo
win
g te
rms:
no
rmal
angl
e of
inci
denc
e an
gle
of re
fl ect
ion
• de
scrib
e an
exp
erim
ent
to il
lust
rate
the
law
of
refl e
ctio
n•
desc
ribe
an e
xper
imen
t to
fi nd
the
pos
ition
of
an im
age
form
ed b
y a
plan
e m
irror
• de
scrib
e th
e pr
oper
ties
of t
he im
age
prod
uced
by
a pl
ane
mirr
or•
know
tha
t th
e an
gle
of in
cide
nce
is e
qual
to t
he a
ngle
of
refl e
ctio
n an
d•
use
this
in d
raw
ing
diag
ram
s an
d ca
lcul
atio
ns
Ref
ract
ion
of li
ght
• de
fi ne
the
follo
win
g:an
gle
of in
cide
nce
angl
e of
refr
actio
nre
frac
tive
inde
x•
desc
ribe
expe
rimen
ts to
sho
w re
frac
tion
of li
ght
thro
ugh
glas
s bl
ocks
• do
cal
cula
tions
usi
ng t
he e
quat
ion
si
n i /
sin
r =
n•
defi n
e th
e te
rms:
cr
itica
l ang
leto
tal i
nter
nal r
efl e
ctio
n•
do c
alcu
latio
ns u
sing
the
equ
atio
n si
n c
= 1
/n•
desc
ribe
expe
rimen
ts to
sho
w to
tal i
nter
nal r
efl e
ctio
n•
desc
ribe
how
opt
ical
fi br
es a
re u
sed
in
tele
com
mun
icat
ions
and
• st
ate
the
adva
ntag
es o
f th
eir
use
Section 4: What you need to know
28 Cambridge O Level Physics 5054
Section 4: What you need to know
28
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Thin
con
verg
ing
and
dive
rgin
g le
nses
• de
scrib
e th
e ac
tion
of t
hin
conv
ergi
ng le
nses
on
a be
am
of li
ght
• de
scrib
e th
e ac
tion
of t
hin
dive
rgin
g le
nses
on
a be
am o
f lig
ht•
defi n
e th
e te
rm fo
cal l
engt
h•
draw
ray
dia
gram
s to
sho
w t
he fo
rmat
ion
of re
al a
nd
virt
ual i
mag
es o
f an
obj
ect
by a
con
verg
ing
lens
• dr
aw r
ay d
iagr
ams
to s
how
the
form
atio
n of
a v
irtua
l im
age
by a
div
ergi
ng le
ns•
defi n
e th
e te
rm li
near
mag
nifi c
atio
n•
draw
sca
le d
iagr
ams
to d
eter
min
e th
e fo
cal l
engt
h of
a c
onve
rgin
g le
ns n
eede
d fo
r pa
rtic
ular
val
ues
of
mag
nifi c
atio
n•
desc
ribe
the
use
of a
sin
gle
lens
:as
a m
agni
fyin
g gl
ass
in a
cam
era
n a
proj
ecto
rin
a p
hoto
grap
hic
enla
rger
• dr
aw r
ay d
iagr
ams
to s
how
how
the
imag
e is
form
ed
by a
mag
nify
ing
glas
s:in
a c
amer
ain
a p
roje
ctor
in a
pho
togr
aphi
c en
larg
er•
draw
ray
dia
gram
s to
sho
w t
he fo
rmat
ion
of im
ages
inth
e no
rmal
eye
:a
shor
t-si
ghte
d ey
ea
long
-sig
hted
eye
• de
scrib
e th
e co
rrec
tion
of s
hort
-sig
ht
• de
scrib
e th
e co
rrec
tion
of lo
ng-s
ight
15.
Ele
ctro
mag
net
ic s
pec
tru
m
Dis
pers
ion
of li
ght
• de
scrib
e th
e di
sper
sion
of
light
by
a gl
ass
pris
m.
• st
ate
the
colo
urs
of t
he s
pect
rum
•
expl
ain
how
the
col
ours
are
rela
ted
to f
requ
ency
and
w
avel
engt
h
Section 4: What you need to know
29 Cambridge O Level Physics 5054
Section 4: What you need to know
29
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Pro
pert
ies
of
elec
trom
agne
tic w
aves
• st
ate
that
all
elec
trom
agne
tic w
aves
tra
vel w
ith t
he s
ame
high
spe
ed in
air
• kn
ow t
hat
the
spee
d is
3 ×
108 m
/s•
list
the
com
pone
nts
of t
he e
lect
rom
agne
tic s
pect
rum
• de
scrib
e th
e im
port
ant
feat
ures
of
each
com
pone
nt o
f th
e el
ectr
omag
netic
spe
ctru
m
App
licat
ions
of
elec
trom
agne
tic w
aves
• di
scus
s ho
w e
ach
com
pone
nt is
use
d:–
radi
owav
es in
rad
io a
nd te
levi
sion
com
mun
icat
ions
– m
icro
wav
es in
sat
ellit
e te
levi
sion
and
in te
leph
ones
– in
fra-
red
in h
ouse
hold
ele
ctric
al a
pplia
nces
:
in te
levi
sion
con
trol
lers
in
intr
uder
ala
rms
– lig
ht in
opt
ical
fi br
es:
in
med
ical
use
s
in te
leph
one
cabl
es–
ultr
a-vi
olet
in s
unbe
ds
in fl
uore
scen
t tu
bes
in
ste
rilis
atio
n–
X-r
ays
in h
ospi
tals
for
med
ical
imag
ing
in
hos
pita
ls fo
r ki
lling
can
cero
us c
ells
in
eng
inee
ring
for
dete
ctin
g cr
acks
in m
etal
obj
ects
– ga
mm
a ra
ys in
hos
pita
ls fo
r ki
lling
can
cero
us c
ells
,
in e
ngin
eerin
g fo
r de
tect
ing
crac
ks in
met
al o
bjec
ts
Section 4: What you need to know
30 Cambridge O Level Physics 5054
Section 4: What you need to know
30
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
16.
So
un
d
Sou
nd w
aves
• de
scrib
e th
e pr
oduc
tion
of s
ound
by
vibr
atin
g so
urce
s•
expl
ain
why
sou
nd w
aves
are
long
itudi
nal
• ex
plai
n w
hat
is m
eant
by
com
pres
sion
s an
d ra
refa
ctio
ns•
stat
e th
e ap
prox
imat
e ra
nge
of a
udib
le f
requ
enci
es•
expl
ain
soun
d w
aves
nee
d a
med
ium
, and
• de
scrib
e an
exp
erim
ent
to d
emon
stra
te t
his
• ex
plai
n ho
w t
he lo
udne
ss o
f a
soun
d w
ave
depe
nds
on
its a
mpl
itude
• ex
plai
n ho
w t
he p
itch
of s
ound
wav
es d
epen
ds o
n its
fr
eque
ncy
• de
scrib
e ho
w t
he re
fl ect
ion
of s
ound
may
pro
duce
an
echo
• ex
plai
n w
hat
is m
eant
by
the
qual
ity (t
imbr
e) o
f a
soun
d w
ave
• de
scrib
e w
hat
affe
cts
the
qual
ity (t
imbr
e) o
f so
und
wav
es, a
nd•
desc
ribe
how
the
se c
an b
e sh
own
on a
cat
hode
ray
os
cillo
scop
e (c
.r.o.
)
Spe
ed o
f so
und
• de
scrib
e a
sim
ple
met
hod
of m
easu
ring
the
spee
d of
so
und
in a
ir, a
nd•
expl
ain
how
the
spe
ed is
cal
cula
ted
from
the
m
easu
rem
ents
• st
ate
appr
oxim
ate
mag
nitu
de o
f th
e sp
eeds
of
soun
din
air
in li
quid
sin
sol
ids
Ultr
asou
nd•
defi n
e ul
tras
ound
• de
scrib
e th
e us
es o
f ul
tras
ound
:in
cle
anin
gin
det
ectin
g fl a
ws
(qua
lity
cont
rol)
in p
re-n
atal
sca
nnin
g
Section 4: What you need to know
31 Cambridge O Level Physics 5054
Section 4: What you need to know
31
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
TH
EM
E 5
Ele
ctri
city
an
d M
agn
etis
m
17.
Mag
net
ism
an
d e
lect
rom
agn
etis
m
Law
s of
mag
netis
m•
know
tha
t m
agne
ts h
ave
N (n
orth
) and
S (s
outh
) pol
es•
stat
e th
at u
nlik
e po
les
attr
act
and
like
pole
s re
pel
Mag
netic
pro
pert
ies
of
mat
ter
• st
ate
the
diff
eren
ces
betw
een
mag
netic
, non
-mag
netic
an
d m
agne
tised
mat
eria
ls•
desc
ribe
an e
lect
rical
met
hod
of m
agne
tisat
ion
• de
scrib
e an
ele
ctric
al m
etho
d of
dem
agne
tisat
ion
• ex
plai
n w
hat
is m
eant
by
a pe
rman
ent
mag
net
• kn
ow t
hat
stee
l beh
aves
as
a pe
rman
ent
mag
net
• de
scrib
e us
es o
f pe
rman
ent
mag
nets
• ex
plai
n w
hat
is m
eant
by
a te
mpo
rary
mag
net
• kn
ow t
hat
iron
beha
ves
as a
tem
pora
ry m
agne
t•
desc
ribe
uses
of
tem
pora
ry m
agne
ts•
expl
ain
wha
t is
mea
nt b
y in
duce
d m
agne
tism
• de
scrib
e ho
w to
plo
t m
agne
tic fi
eld
lines
with
a p
lott
ing
com
pass
• ex
plai
n w
hat
is m
eant
by
mag
netic
scr
eeni
ng•
expl
ain
the
choi
ce o
f m
ater
ial f
or m
agne
tic s
cree
ning
• de
scrib
e th
e us
e of
mag
netic
mat
eria
ls in
a c
ompu
ter
hard
dis
k dr
ive
Elec
trom
agne
tism
• de
scrib
e th
e pa
tter
n of
the
mag
netic
fi el
d du
e to
:cu
rren
ts in
str
aigh
t w
ires
curr
ents
in s
olen
oids
• st
ate
the
effe
ct o
n th
e m
agne
tic fi
eld
of c
hang
ing:
th
e m
agni
tude
of
the
curr
ent
the
dire
ctio
n of
the
cur
rent
• de
scrib
e us
es o
f el
ectr
omag
nets
in:
rela
ysci
rcui
t-br
eake
rslo
udsp
eake
rs
Section 4: What you need to know
32 Cambridge O Level Physics 5054
Section 4: What you need to know
32
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
18.
Sta
tic
elec
tric
ity
Law
s of
ele
ctro
stat
ics
• kn
ow t
hat
ther
e ar
e po
sitiv
e an
d ne
gativ
e ch
arge
s•
stat
e th
at u
nlik
e ch
arge
s at
trac
t an
d lik
e ch
arge
s re
pel
Prin
cipl
es o
f el
ectr
osta
tics
• de
scrib
e ex
perim
ents
to s
how
ele
ctro
stat
ic c
harg
ing
by
fric
tion
• ex
plai
n th
at c
harg
ing
of s
olid
s in
volv
es a
mov
emen
t of
el
ectr
ons
• kn
ow t
hat
char
ge is
mea
sure
d in
cou
lom
bs•
desc
ribe
an e
lect
ric fi
eld
as a
regi
on in
whi
ch a
n el
ectr
ic
char
ge e
xper
ienc
es a
forc
e•
stat
e th
e di
rect
ion
of li
nes
of fo
rce
(ele
ctric
fi el
d lin
es)
• de
scrib
e si
mpl
e el
ectr
ic fi
eld
patt
erns
• de
scrib
e th
e se
para
tion
of c
harg
es b
y in
duct
ion
• ex
plai
n th
e di
ffer
ence
s be
twee
n el
ectr
ical
con
duct
ors
and
insu
lato
rs
• gi
ve e
xam
ples
of
elec
tric
al c
ondu
ctor
s•
give
exa
mpl
es o
f el
ectr
ical
insu
lato
rs•
expl
ain
wha
t is
mea
nt b
y ‘e
arth
ing’
a c
harg
ed o
bjec
t
App
licat
ions
of
elec
tros
tatic
s•
desc
ribe
exam
ples
whe
re c
harg
ing
coul
d be
a p
robl
em,
e.g.
ligh
tnin
g•
desc
ribe
exam
ples
whe
re c
harg
ing
is h
elpf
ul, e
.g.
phot
ocop
ier,
elec
tros
tatic
pre
cipi
tato
r
19.
Cu
rren
t el
ectr
icit
y
Cur
rent
• st
ate
that
a c
urre
nt is
a fl
ow o
f ch
arge
•
know
tha
t cu
rren
t is
mea
sure
d in
am
pere
s•
do c
alcu
latio
ns u
sing
the
equ
atio
n
char
ge =
cur
rent
× ti
me
• de
scrib
e th
e us
e of
an
amm
eter
with
diff
eren
t ra
nges
Section 4: What you need to know
33 Cambridge O Level Physics 5054
Section 4: What you need to know
33
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Elec
trom
otiv
e fo
rce
(e.m
.f.)
• ex
plai
n th
at e
.m.f.
is t
he e
nerg
y co
nver
ted
by a
pow
er
supp
ly (e
.g. c
ell)
in m
ovin
g a
unit
char
ge a
roun
d a
circ
uit
• st
ate
that
e.m
.f. is
wor
k do
ne/c
harg
e•
calc
ulat
e th
e to
tal e
.m.f.
whe
n se
vera
l pow
er s
uppl
ies
are
arra
nged
in s
erie
s, a
nd
• de
scrib
e ho
w t
his
is u
sed
in t
he d
esig
n of
bat
terie
s•
expl
ain
the
adva
ntag
e of
mak
ing
a ba
tter
y fr
om s
ever
al
pow
er s
uppl
ies
arra
nged
in p
aral
lel
Pot
entia
l diff
eren
ce (p
.d.)
• kn
ow t
hat
p.d.
is m
easu
red
in v
olts
• ex
plai
n th
at t
he p
.d. i
s m
easu
red
acro
ss a
circ
uit
com
pone
nt
• ex
plai
n th
at t
he p
.d. a
cros
s a
com
pone
nt is
the
wor
k do
ne w
hen
a un
it ch
arge
pas
ses
thro
ugh
the
com
pone
nt•
stat
e th
at t
he v
olt
is g
iven
by
J/C
• de
scrib
e th
e us
e of
a v
oltm
eter
with
diff
eren
t ra
nges
Section 4: What you need to know
34 Cambridge O Level Physics 5054
Section 4: What you need to know
34
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Res
ista
nce
• kn
ow t
hat
resi
stan
ce =
p.d
./cur
rent
• do
cal
cula
tions
usi
ng t
he e
quat
ion
re
sist
ance
= v
olta
ge/c
urre
nt•
desc
ribe
an e
xper
imen
t to
mea
sure
the
resi
stan
ce o
f a
met
allic
con
duct
or u
sing
a v
oltm
eter
and
an
amm
eter
• st
ate
Ohm
’s L
aw•
expl
ain
that
Ohm
’s L
aw is
onl
y ob
eyed
by
a re
sist
or a
t co
nsta
nt te
mpe
ratu
re•
do c
alcu
latio
ns w
ith t
he re
latio
nshi
ps fo
r a
wire
:
resi
stan
ce is
dire
ctly
pro
port
iona
l to
leng
th
resi
stan
ce is
inve
rsel
y pr
opor
tiona
l to
cros
s-se
ctio
nal
area
• ca
lcul
ate
the
tota
l res
ista
nce
of s
ever
al re
sist
ors:
in s
erie
sin
par
alle
l•
sket
ch c
urre
nt/v
olta
ge g
raph
s fo
r:re
sist
orfi l
amen
t la
mp
• de
scrib
e th
e ef
fect
of
tem
pera
ture
incr
ease
on
the
resi
stan
ce o
f:a
resi
stor
a fi l
amen
t la
mp
• de
scrib
e ho
w t
he re
sist
ance
of
a lig
ht-d
epen
dent
resi
stor
va
ries
with
the
inte
nsity
of
light
Section 4: What you need to know
35 Cambridge O Level Physics 5054
Section 4: What you need to know
35
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
20.
D.C
. cir
cuit
s
Cur
rent
and
pot
entia
l di
ffer
ence
in c
ircui
ts•
know
the
circ
uit
sym
bols
for:
pow
er s
ourc
es (c
ell,
batt
ery
or a
.c. m
ains
)sw
itche
s (c
lose
d an
d op
en)
esis
tors
(fi x
ed a
nd v
aria
ble)
light
dep
ende
nt re
sist
ors
ther
mis
tors
.la
mps
amm
eter
svo
ltmet
ers
mag
netis
ing
coils
bells
fuse
sre
lays
light
-em
ittin
g di
odes
rect
ifyin
g di
odes
.•
draw
circ
uits
con
tain
ing
thes
e co
mpo
nent
s
Ser
ies
and
para
llel
circ
uits
• st
ate
that
the
cur
rent
at
ever
y po
int
in a
ser
ies
circ
uit
is
the
sam
e•
stat
e th
at t
he s
um o
f th
e p.
d.s
in a
ser
ies
circ
uit
is e
qual
to
the
p.d
. acr
oss
the
who
le c
ircui
t •
stat
e th
at t
he c
urre
nt f
rom
the
sou
rce
is t
he s
um o
f th
e cu
rren
ts in
the
sep
arat
e br
anch
es o
f a
para
llel c
ircui
t•
do c
alcu
latio
ns o
n th
e w
hole
circ
uit,
reca
lling
and
usi
ng
form
ulae
incl
udin
g R
= V
/I a
nd t
hese
for
pote
ntia
l di
ffer
ence
s in
ser
ies,
resi
stor
s in
ser
ies
and
resi
stor
s in
pa
ralle
l
Section 4: What you need to know
36 Cambridge O Level Physics 5054
Section 4: What you need to know
36
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
21. P
ract
ical
ele
ctri
city
Use
s of
ele
ctric
ity•
desc
ribe
the
use
of e
lect
ricity
in:
heat
ing
light
ing
mot
ors
• do
cal
cula
tions
usi
ng t
he e
quat
ions
po
wer
= v
olta
ge ×
cur
rent
en
ergy
= v
olta
ge ×
cur
rent
× ti
me
• ca
lcul
ate
the
cost
of
usin
g el
ectr
ical
app
lianc
es w
here
th
e en
ergy
uni
t is
the
kW
h
Dan
gers
of
elec
tric
ity•
stat
e th
e ha
zard
s of
:da
mag
ed in
sula
tion
over
heat
ing
of c
able
sda
mp
cond
ition
s
Saf
e us
e of
ele
ctric
ity in
th
e ho
me
• de
scrib
e th
e us
e of
:fu
ses
circ
uit
brea
kers
• ex
plai
n w
hat
is m
eant
by:
fuse
rat
ings
circ
uit
brea
ker
sett
ings
• ex
plai
n th
e ne
ed fo
r:ea
rthi
ng m
etal
cas
esdo
uble
insu
latio
n•
stat
e th
e m
eani
ng o
f th
e te
rms:
live
neut
ral
eart
h•
desc
ribe
how
to w
ire a
mai
ns p
lug
• ex
plai
n w
hy s
witc
hes,
fus
es a
nd c
ircui
t br
eake
rs a
re
alw
ays
plac
ed in
the
live
con
duct
or
Section 4: What you need to know
37 Cambridge O Level Physics 5054
Section 4: What you need to know
37
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
22.
Ele
ctro
mag
net
ism
Forc
e on
a c
urre
nt-
carr
ying
con
duct
or•
desc
ribe
expe
rimen
ts to
sho
w t
he fo
rce
on:
a cu
rren
t-ca
rryi
ng c
ondu
ctor
in a
mag
netic
fi el
da
beam
of
char
ged
part
icle
s in
a m
agne
tic fi
eld
• de
scrib
e th
e ef
fect
on
the
forc
e of
:re
vers
ing
the
curr
ent
reve
rsin
g th
e di
rect
ion
of t
he fi
eld
• st
ate
the
rela
tive
dire
ctio
ns o
f fo
rce,
fi el
d an
d cu
rren
t:(u
se o
f Fl
emin
g’s
left
han
d ru
le)
• de
scrib
e th
e m
agne
tic fi
eld
patt
erns
bet
wee
n cu
rren
ts in
pa
ralle
l con
duct
ors
• us
e th
e m
agne
tic fi
eld
patt
erns
to fi
nd t
he d
irect
ion
of
the
forc
es o
n th
e w
ires
The
d.c.
mot
or•
expl
ain
how
a c
urre
nt-c
arry
ing
coil
in a
mag
netic
fi el
d ex
perie
nces
a t
urni
ng e
ffec
t•
desc
ribe
the
effe
ct o
f:in
crea
sing
the
num
ber
of t
urns
on
the
coil
incr
easi
ng t
he c
urre
nt•
desc
ribe
how
thi
s tu
rnin
g ef
fect
is u
sed
in a
n el
ectr
ic
mot
or•
expl
ain
why
a s
plit-
ring
com
mut
ator
is u
sed
in a
sim
ple
mot
or•
desc
ribe
the
effe
ct o
f w
indi
ng t
he c
oil o
nto
a so
ft-ir
on
cylin
der
23. E
lect
rom
agn
etic
ind
uct
ion
Prin
cipl
es o
f el
ectr
omag
netic
in
duct
ion
• de
scrib
e an
exp
erim
ent
whi
ch s
how
s th
at a
cha
ngin
g m
agne
tic fi
eld
can
indu
ce a
n e.
m.f.
in a
circ
uit
• st
ate
the
fact
ors
affe
ctin
g th
e m
agni
tude
of
the
indu
ced
e.m
.f.•
know
tha
t th
e di
rect
ion
of a
cur
rent
pro
duce
d by
an
indu
ced
e.m
.f. o
ppos
es t
he c
hang
e pr
oduc
ing
it (L
enz’
s La
w)
• de
scrib
e a
sim
ple
dem
onst
ratio
n of
Len
z’s
Law
Section 4: What you need to know
38 Cambridge O Level Physics 5054
Section 4: What you need to know
38
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
The
a.c.
gen
erat
or•
desc
ribe
a si
mpl
e fo
rm o
f a.
c. g
ener
ator
(rot
atin
g co
il or
ro
tatin
g m
agne
t)•
expl
ain
the
purp
ose
of s
lip r
ings
(whe
re n
eede
d)•
sket
ch a
gra
ph o
f vo
ltage
out
put
agai
nst
time
for
a si
mpl
e a.
c. g
ener
ator
The
tran
sfor
mer
• de
scrib
e th
e st
ruct
ure
of a
sim
ple
iron-
core
d tr
ansf
orm
er•
desc
ribe
the
oper
atio
n of
a s
impl
e iro
n-co
red
tran
sfor
mer
• st
ate
the
adva
ntag
es o
f hi
gh v
olta
ge t
rans
mis
sion
• co
mpa
re u
nder
grou
nd p
ower
tra
nsm
issi
on w
ith o
verh
ead
lines
in te
rms
of:
envi
ronm
enta
l im
pact
cost
24.
Intr
od
uct
ory
ele
ctro
nic
s
Ther
mio
nic
emis
sion
• st
ate
that
ele
ctro
ns a
re e
mitt
ed b
y a
hot
met
al fi
lam
ent
• ex
plai
n th
at to
allo
w t
he e
lect
rons
to fl
ow re
quire
s bo
th:
high
pos
itive
pot
entia
lve
ry lo
w g
as p
ress
ure
• de
scrib
e th
e de
fl ect
ion
of a
n el
ectr
on b
eam
by:
elec
tric
fi el
dsm
agne
tic fi
elds
• st
ate
that
the
fl ow
of
elec
tron
s (e
lect
ron
curr
ent)
is f
rom
ne
gativ
e to
pos
itive
• kn
ow t
hat
the
fl ow
of
elec
tron
s is
in t
he o
ppos
ite
dire
ctio
n to
con
vent
iona
l cur
rent
Sim
ple
trea
tmen
t of
ca
thod
e-ra
y os
cillo
scop
e (c
.r.o.
)
• de
scrib
e in
out
line
the
basi
c st
ruct
ure
of a
c.r.
o.•
desc
ribe
in o
utlin
e th
e ac
tion
of a
c.r.
o.•
desc
ribe
the
use
of a
c.r.
o.:
to d
ispl
ay w
avef
orm
sto
mea
sure
p.d
.s.
to m
easu
re s
hort
inte
rval
s of
tim
e
Section 4: What you need to know
39 Cambridge O Level Physics 5054
Section 4: What you need to know
39
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Act
ion
and
use
of c
ircui
t co
mpo
nent
s•
desc
ribe
the
resi
stor
col
our
code
• ex
plai
n ho
w t
he re
sist
or c
olou
r co
de c
an e
asily
be
used
to
labe
l ver
y la
rge
and
very
sm
all r
esis
tanc
es•
expl
ain
why
wid
ely
diff
eren
t va
lues
of
resi
stan
ce a
re
need
ed in
diff
eren
t ty
pes
of c
ircui
t•
expl
ain
why
we
need
to u
se re
sist
ors
with
ver
y di
ffer
ent
pow
er r
atin
gs
• de
scrib
e th
e ac
tion
of a
the
rmis
tor
• ex
plai
n th
e us
e of
a t
herm
isto
r as
an
inpu
t se
nsor
• de
scrib
e th
e ac
tion
of a
ligh
t-de
pend
ent
resi
stor
• ex
plai
n th
e us
e of
a li
ght-
depe
nden
t re
sist
or a
s an
inpu
t se
nsor
• de
scrib
e th
e ac
tion
of a
var
iabl
e po
tent
ial d
ivid
er
(pot
entio
met
er)
• de
scrib
e th
e ac
tion
of a
dio
de in
pas
sing
cur
rent
in o
ne
dire
ctio
n on
ly•
desc
ribe
the
actio
n of
a li
ght-
emitt
ing
diod
e in
pas
sing
cu
rren
t in
one
dire
ctio
n on
ly a
nd e
mitt
ing
light
• de
scrib
e th
e ac
tion
of a
cap
acito
r as
a c
harg
e st
ore
• ex
plai
n ho
w a
cap
acito
r is
use
d in
tim
e de
lay
circ
uits
• de
scrib
e th
e ac
tion
of a
rela
y•
expl
ain
how
rela
ys a
re u
sed
in s
witc
hing
circ
uits
• de
scrib
e ci
rcui
ts o
pera
ting
as:
light
-sen
sitiv
e sw
itche
ste
mpe
ratu
re o
pera
ted
alar
ms
(usi
ng a
rela
y or
oth
er c
ircui
ts)
Section 4: What you need to know
40 Cambridge O Level Physics 5054
Section 4: What you need to know
40
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
25.
Ele
ctro
nic
sys
tem
s (N
ote
th
is t
op
ic is
op
tio
nal
. Qu
esti
on
s ar
e al
way
s se
t as
alt
ern
ativ
es.)
Sw
itchi
ng a
nd lo
gic
circ
uits
• de
scrib
e th
e ac
tion
of a
n np
n tr
ansi
stor
as
an e
lect
rical
ly
oper
ated
sw
itch
• ex
plai
n th
e us
e of
an
npn
tran
sist
or in
sw
itchi
ng c
ircui
ts.
• st
ate
in w
ords
and
in t
ruth
tab
le fo
rm, t
he a
ctio
n of
the
fo
llow
ing
logi
c ga
tes:
AN
DO
RN
AN
DN
OR
NO
T (in
vert
er).
• st
ate
the
sym
bols
for
the
logi
c ga
tes
liste
d ab
ove
Bis
tabl
e an
d as
tabl
e ci
rcui
ts•
desc
ribe
the
use
of a
bis
tabl
e ci
rcui
t•
know
tha
t bi
stab
le c
ircui
ts e
xhib
it th
e pr
oper
ty o
f m
emor
y•
desc
ribe
the
use
of a
n as
tabl
e ci
rcui
t (p
ulse
gen
erat
or)
• de
scrib
e ho
w t
he f
requ
ency
of
an a
stab
le c
ircui
t is
re
late
d to
the
val
ues
of t
he re
sist
ive
and
capa
cita
tive
com
pone
nts
TH
EM
E 6
Ato
mic
Ph
ysic
s
26. R
adio
acti
vity
Det
ectio
n of
rad
ioac
tivity
• de
scrib
e th
e de
tect
ion
of:
alph
a-pa
rtic
les
beta
-par
ticle
sga
mm
a-ra
ys
Cha
ract
eris
tics
of t
he
thre
e ty
pes
of e
mis
sion
• ex
plai
n w
hat
is m
eant
by
radi
oact
ive
deca
y•
for
each
rad
ioac
tive
emis
sion
, sta
te:
the
natu
reth
eir
rela
tive
ioni
sing
eff
ect
thei
r re
lativ
e pe
netr
atin
g po
wer
•
stat
e an
d ex
plai
n th
e ra
ndom
em
issi
on o
f ra
dioa
ctiv
ity in
di
rect
ion
and
time
• de
scrib
e th
e de
fl ect
ion
of r
adio
activ
e em
issi
ons
in:
elec
tric
fi el
dsm
agne
tic fi
elds
Section 4: What you need to know
41 Cambridge O Level Physics 5054
Section 4: What you need to know
41
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Nuc
lear
reac
tions
• ex
plai
n w
hat
is m
eant
by
fusi
on•
expl
ain
wha
t is
mea
nt b
y fi s
sion
• de
scrib
e w
ith t
he a
id o
f a
bloc
k di
agra
m o
ne t
ype
of
fi ssi
on re
acto
r fo
r us
e in
a p
ower
sta
tion
• de
scrib
e st
ar fo
rmat
ion
and
expl
ain
how
ene
rgy
is
prod
uced
by
fusi
on
Hal
f-lif
e•
expl
ain
wha
t is
mea
nt b
y ha
lf-lif
e•
do c
alcu
latio
ns b
ased
on
half-
life
usin
g:in
form
atio
n in
tab
les
deca
y cu
rves
Use
s of
rad
ioac
tive
isot
opes
incl
udin
g sa
fety
pr
ecau
tions
• de
scrib
e ho
w r
adio
activ
e m
ater
ials
are
:ha
ndle
dus
edst
ored
in a
saf
e w
ay•
expl
ain
how
the
cho
ice
of a
rad
ioac
tive
mat
eria
l for
a
part
icul
ar u
se d
epen
ds o
n:th
e ty
pe o
f ra
diat
ion
emitt
edth
e ha
lf-lif
e•
desc
ribe
the
orig
ins
and
effe
ct o
f ba
ckgr
ound
rad
iatio
n•
desc
ribe
the
datin
g of
obj
ects
by
the
use
of 14
C
27.
Th
e n
ucl
ear
ato
m
Ato
mic
mod
el•
desc
ribe
the
stru
ctur
e of
the
ato
m in
term
s of
nuc
leus
an
d el
ectr
ons
• de
scrib
e ho
w t
he G
eige
r–M
arsd
en a
lpha
-par
ticle
sc
atte
ring
expe
rimen
t pr
ovid
es e
vide
nce
for
the
nucl
ear
atom
Section 4: What you need to know
42 Cambridge O Level Physics 5054
Section 4: What you need to know
42
Top
icY
ou
sh
ou
ld b
e ab
le t
o:
Ch
eckl
ist
Co
mm
ents
Nuc
leus
• de
scrib
e th
e co
mpo
sitio
n of
the
nuc
leus
in te
rms
of
prot
ons
and
neut
rons
• de
fi ne
the
term
s:
prot
on n
umbe
r (at
omic
num
ber),
Znu
cleo
n nu
mbe
r (m
ass
num
ber),
A•
expl
ain
the
term
nuc
lide
• us
e th
e nu
clid
e no
tatio
n A Z X
in e
quat
ions
whe
re
radi
oact
ive
deca
y ca
uses
the
nuc
leus
to c
hang
e•
defi n
e th
e te
rm is
otop
e•
expl
ain,
usi
ng n
uclid
e no
tatio
n, h
ow o
ne e
lem
ent
may
ha
ve a
num
ber
of is
otop
es
Section 5: Useful websites
43 Cambridge O Level Physics 5054
Section 5: Useful websites
You may fi nd the websites below useful in your revision or if you want extra help. The syllabus covered in the website does not always match the Cambridge O Level syllabus, so choose carefully.
www.physics.org An Institute of Physics site. If you have a burning question, you will be directed to other relevant websites.
www.bbc.co.uk/schools/gcsebitesize/physics A BBC website dedicated to revision and simple testing.
www.gcse.com/physics.htm A useful site that deals with many topics in an interesting way.
www.colpus.me.uk/vplabd/?q=node/1 A group of simulations. Try the free sample and play with an oscilloscope, transformer, lenses etc. if you do not want to buy all of the simulations.
www.s-cool.co.uk/gcse/physicsBasic theory and online testing.
www.gcsescience.com Basic theory and online testing that might help revision.
Useful websites
44 Cambridge O Level Physics 5054
Section 6: Appendices
45 Cambridge O Level Physics 5054
Section 6: Appendices
Symbols, units and defi nitions of physical quantitiesYou should be able to state the symbols for the following physical quantities and, where indicated, state the units in which they are measured.
You should be familiar with the following multipliers: M mega, k kilo, c centi, m milli.
Quantity Symbol Unit
length l, h … km, m, cm, mm
area A m2, cm2
volume V m3, cm3
weight W N
mass m, M kg, g, mg
time t h, min, s, ms
density ρ g/cm3, kg/m3
speed u, v, km/h, m/s, cm/s
acceleration a m/s2
acceration of free fall g m/s2
force F, P … N
gravitational fi eld strength g N/kg
moment of force Nm
work done W, E J
energy E J, kWh
power P W
pressure p, P Pa, N/m2
temperature θ, t, T oC
heat capacity C J/oC
specifi c heat capacity c /(kgoC), J/(goC)
latent heat L J
specifi c latent heat l J/kg, J/g
frequency f Hz
wavelength λ m, cm
focal length f m, cm
angle of incidence i degree (o)
angles of refl ection, refraction r degree (o)
Section 6: Appendices
46 Cambridge O Level Physics 5054
Quantity Symbol Unit
critical angle c degree (o)
refractive index n
potential difference / voltage V V, mV
current I A, mA
charge Q C
e.m.f. E V
resistance R Ω
Command words and phrasesWe use command words to help you to write down the answer examiners are looking for. This table explains what each of these words or phrases means and will help you to understand the kind of answer you should write. The list is in alphabetical order. You should bear in mind that the meaning of a term may vary slightly according to how the question is worded.
Command word/phrase
Meaning
Calculate A numerical answer is needed. Show your working, especially when there are two or more steps in a calculation.
Deduce This may be used in two ways:• You fi nd the answer by working out the patterns in the information given to you
and drawing logical conclusions from them. You may need to use information from tables and graphs and do calculations, e.g. deduce what will happen to the velocity of the vehicle if …
• You have to refer to a Law or scientifi c theory or give a reason for your answer,e.g. use your knowledge of the kinetic theory to deduce what will happen when …
Defi ne A formal statement of a quantity is required. You can sometimes give a defi ning equation, e.g. speed = d/t, as long as you state what the symbols are that you use in your equation, in the example given d = distance, t = time.
Describe Try to set out a logical sequence that allows the reader to follow the main points about something. You may use labelled diagrams if you fi nd it easier, e.g. describe a rotating-coil generatorYou may also be asked to describe:• observations, e.g. describe the ways in which a force may change the motion of
a body• how to do particular experiments, e.g. describe an experiment to determine
resistance using a voltmeter and an ammeter.
Determine You are expected to use a formula or method that you know to calculate a quantity,e.g. determine graphically the resultant of two vectors.
Discuss You must write down points for and against an argument, e.g. discuss the supply of energy with a nuclear power station.
Section 6: Appendices
47 Cambridge O Level Physics 5054
Command word/phrase
Meaning
Estimate Give an approximate value for a quantity based on reasons and data. You may need to make some approximations, e.g. estimate the volume of a test tube.
Explain You must give reasons for your answer or refer to a particular theory.
List Write down a number of separate points. Where the number of points is stated in the question, you should not write more than this number.
Measure You are expected to fi nd a quantity by using a measuring instrument, e.g. length by using a ruler, or angle by using a protractor.
Outline State the main points briefl y, e.g. outline a method of magnetising an iron bar.
Predict This can be used in two ways:• You fi nd the answer by working out the patterns in the information provided
and drawing logical conclusions from this. You may need to use information from tables and graphs and do calculations, e.g. predict what will happen to the direction of the resultant force if …
• It may also mean stating what might happen next e.g. predict what effect an increase in temperature will have on the resistance.
Sketch When drawing graphs, this means that you draw the approximate shape and/or position of the graph. You need to make sure that important details, such as the line passing through the origin or fi nishing at a certain point, are drawn accurately.
When drawing apparatus or other diagrams, a simple line drawing is all that is needed, but make sure that the proportions are correct and the most important details are shown. Always label diagrams.
State You should give a short answer without going into any detail or explanation.
Suggest This may be used in two ways:• There may be more than one correct answer, e.g. suggest a precaution to
improve the accuracy of the experiment.• You are being asked to apply your general knowledge of physics or reasoning
skills to a topic area that is not directly on the syllabus, e.g. applying ideas about moments to the stability of a vehicle.
What is meant by/What do you understand by
You should defi ne something and also make a more detailed comment about it, e.g. what do you understand by the term total internal refl ection.
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