Sackville School
Science Department
Physics Revision Workbook
M. Manser
OCR Gateway
GCSE Physics B
Physics P1:
‘Energy for the home’
M Manser
1
CONTENTS
Page
Item
HEATING HOUSES
3
6
10
P1a Revision Tasks
P1a Examination Questions
P1a Checklist
KEEPING HOMES WARM
11
14
19
P1b Revision Tasks
P1b Examination Questions
P1b Checklist
A SPECTRUM OF WAVES
21
26
30
P1c Revision Tasks
P1c Examination Questions
P1c Checklist
LIGHT AND LASERS
31
34
36
P1d Revision Tasks
P1d Examination Questions
P1d Checklist
COOKING AND COMMUNICATING USING WAVES
37
39
43
P1e Revision Tasks
P1e Examination Questions
P1e Checklist
DATA TRANSMISSION
44
46
48
P1f Revision Tasks
P1f Examination Questions
P1f Checklist
WIRELESS SIGNALS
43
44
49
P1g Revision Tasks
P1g Examination Questions
P1g Checklist
43
44
49
STABLE EARTH
P1h Revision Tasks
P1h Examination Questions
P1h Checklist
M Manser
2
P1a: HEATING HOUSES
TASK 1: Complete the sentences below about thermal energy.
Heat is a form of ______________ and is
measured in ______________. The symbol for
this unit is _____.
Heat always flows from ______________ areas to
______________ areas. The greater the
______________ difference, the ______________
heat will flow between the two areas.
______________ is a measure of the hotness of an object and is measured in
______________ ______________ . The symbol for this unit is _____.
A ______________, such as the picture above, may be used to identify hot areas. Hot
regions are shown by __________________________________________ . Colder areas
are __________________________________________ .
M Manser
3
Temperature
TASK 2: The graph below illustrates a block of ice that is warmed until it melts, boils then
vapourises completely. Fill in the blanks in the flow map below. It describes what the heat energy
(that is absorbed) is used for.
Time (seconds)
A: As thermal energy
B: At 0oC, the ice begins to
C: Once all the ice has melted
is _______________
_______________. The
and only _______________ is
by the water
energy that is being absorbed
present, the _______________
_______________,
is being used to separate the
of the water will start
they begin
molecules and
_______________. Once
_______________
_______________
again, this is because the
more vigorously as
_______________ between
_______________ energy of
their
them. The temperature of the
the particles is
_______________
ice and water mixture will not
_______________ again.
energy increases.
_______________.
D: At 100oC, the water begins to
C: Once all the water has vapourised
_______________. The energy that is being
and only _______________ is present,
absorbed is being used to separate the molecules
the _______________ of the steam will
and _______________ _______________ between
start _______________. Once again,
them. The temperature of the _______________
this is because the _______________
and water mixture will not _______________.
energy of the particles is
_______________ again.
M Manser
4
TASK 3: There are two heat energy equations that you will be given on your formula list on
the first page of your examination paper.
 Complete the definitions
 Create the ‘triangles’ that will help you to rearrange the equation in the exam.
 Complete the diagram by writing the units for the quantities you have written
in the triangles
The specific heat capacity of a substance is the amount of ______________ that 1kg of a
substance will absorb for its _______________ to increase by 1oC.
energy
=
mass
x
specific heat capacity x
temperature change
UNIT
UNIT
UNIT
UNIT
The specific latent heat of a substance is the amount of ______________ that 1kg of a substance
needs to change its _______________ without any temperature _______________.
energy
=
mass
x
specific latent heat
UNIT
UNIT
M Manser
UNIT
5
P1a PRACTICE EXAMINATION QUESTIONS
1.
Justin is eating a meal.
The temperature of the room is
20 °C.
Look at the diagram.
(a)
Justin notices two things
•
his meal cools down
•
his drink warms up.
(i)
Explain why his
meal cools down.
.............................................................................................................. [1]
(ii)
Explain why his drink warms up.
.............................................................................................................. [1]
(b)
Temperature is measured in degrees Celsius (°C). Heat is measured in joules (J).
Complete the following two sentences. Choose from
capacity
coldness
energy
hotness
mass
Temperature is a measure of the …………………………of an object.
Heat is a measurement of the ………………………… in an object. [2]
[Total 4 marks]
2.
Jack heats a beaker containing some ice.
He measures the temperature of the contents of the beaker every 30 seconds and
records the results.
He draws a graph to show how the temperature changes. This is his graph. (next
page)
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6
(a)
(i)
Complete the sentence. Choose words from this list.
energy
mass
state
temperature
time
The specific latent heat of ice is the ………………………… needed to
change 1 kg of ice into water without a change in ……………………… [2]
(ii)
Explain what happens to the energy supplied as the ice changes to
water.
............................................................................................................... [1]
(b)
The ice has all melted.
Jack discovers that 105 kJ of energy is needed to raise the temperature of 0.5
kg of water by 50 °C.
Calculate the specific heat capacity of water. The list of equations may help
you.
........................................................................................................................
........................................................................................................................
........................................................................................................................
answer .......................................... J / kg °C [2] [Total 5 marks]
M Manser
7
3.
(a)
Doctors use thermometers to measure a patient’s temperature. They
sometimes take a picture called a thermogram. The thermogram shows the
temperatures of different parts of the skin. How does a thermogram show
different temperatures?
........................................................................................................................ [1]
(b)
Jasmine investigates how much heat is needed to melt ice. She uses the
following equipment. Look at the diagram.
The heater melts 4.2 g of ice.
This takes 1500 joules of energy.
Calculate the specific latent heat of ice. The list of equations may help you.
........................................................................................................................
........................................................................................................................
........................................................................................................................
answer ............................................................ J/g [2] [Total 3 marks]
M Manser
8
thermometer
4.
Dave collects some ice from the freezer.
He heats the ice with a Bunsen burner and measures the
temperature. Look at the graph of his results.
ice
beaker
heat
(a)
The ice melts in part B.
There is no change in
temperature when the ice is
melting even though the Bunsen
burner is still heating the ice.
10
temperature
in ºC
0
What is the energy from the
Bunsen burner used for when
the ice is melting?
B
C
A
–10
time
........................................................................................................................
........................................................................................................................
........................................................................................................................ [2]
(b)
Look at the energy statements A, B, C and D below.
A
the energy needed to raise the temperature of 1 kg of ice by 1 °C
B
the energy needed to heat ice
C
the energy needed to melt 1 kg of ice
D
the energy needed to cool ice
(i)
Which letter describes the specific latent heat of ice?
Choose from the list.
A
B
C
D
................................................................................................. [1]
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9
(ii)
Which letter describes the specific heat capacity of ice?
Choose from the list.
A
B
C
D
................................................................................................ [1]
[Total 4 marks]
Student Checklist
Tick column A when you have reviewed the notes on this objective.
Tick column B when you can complete questions and tasks on this objective and get the correct
answer
Tick column MMA if you need additional help
P1a
I can:
HEATING HOUSES
A
B
MMA
Recognise that heat is a form of energy and is measured in
Joules
Recognise that heat flow is directed by temperature difference
State that temperature is a degree of hotness and is measured
in oC
Understand that temperature is a measurement of the average
kinetic energy of particles.
Use a thermogram to identify hot areas
Define specific heat capacity and understand that this measures
the quantity of heat which a material can hold
Select and use the formula
energy = mass x
specific
x
temperature
heat capacity
change
Recognise that energy is being transferred when materials melt
or boil although there is no change in temperature
Define specific latent heat.
Select and use the formula: energy = mass x
specific
latent heat
Explain that energy is needed to break intermolecular bonds
during changes of state
Back to contents
M Manser
10
P1b: KEEPING HOMES WARM
TASK 1: This task is on heat transfer. Fill in the blanks in the sentences below using the words in
the box. Words may be used more than once or not at all
solid
liquid
gaseous
vibrations
cooler
hotter
free
fixed
insulators
conductors
kinetic
electrical
Conduction is the transfer of heat energy from a _______________ region to a _______________
region by the _______________ of particles. This is the way that heat moves through
_______________ substances.
Metals are good _______________ since they have _______________ electrons which transfer the
_______________ energy through the object quickly
radiation
currents
convection
fixed
fluids
particles
rises
falls
hotter
density
area
electrical
When moving _______________ carry energy from one place to another, this is called
_______________. This is the way that heat moves through _______________.
As the liquid (or gas) is heated, its _______________ decreases and it _______________. Cooler
liquid falls and is heated. This cycle sets up _______________ _______________.
radiation
convection
cooler
absorb
hot
black
infrared
shiny
silver
dull
hotter
thermogram
_______________ is the transfer of heat by _______________ waves. Anything that is
_______________ will emit these invisible waves. The _______________ the object is, the more it
will emit. These waves can be shown using a _______________ where yellow and orange show areas
which are _______________. When an object is cool, it will _______________ heat quickly if its
surface is black and dull. If the object is hot, it will radiate heat to the surroundings better if it is
_______________ and _______________.
M Manser
11
TASK 2: Complete the table below. It shows different features that may be used in a house to limit
the flow of heat in and out of the house. Some of it is done for you as an example.
DESIGN FEATURE
THIS IS ……
c_____________
wall
i_____________
DESCRIPTION
HOW IT WORKS:
- STOPS / REDUCES
- CONDUCTION /
CONVECTION /
RADIATION
Two walls of brick, with
the gap in between them
filled with expanded
polystyrene
1. With two walls, the
heat has to travel
further, which takes
longer. Conduction is
reduced
2. Expanded polystyrene
is a good insulator.
Conduction is
reduced
3. Polystyrene traps air,
it cannot move in or
out. Convection is
stopped.
d_____________
g_____________
_____________
_____________
_____________
_____________
M Manser
12
TASK 3: Answer the questions below about payback time.
1. Fill in the blanks.
When an energy saving feature is added to a home it costs money to buy and to install.
The device then saves you money on your heating bills. The _______________ taken to
recover the money spent is called the _______________ _______________.
_______________ =
total cost . ………….you will not be given this equation on
savings per year
on the formula sheet
2. (a) Buying and installing draught proofing strips for a particular house will cost£60 and
will then help to save £20 each year. Calculate the payback time.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
(b) Loft insulation for the same house in (a) costs £250 and will save £100 every year
after. Which method is the most cost effective? Explain your answer.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
Task 4: Look at the equation used to calculate the efficiency of a device. Which Sankey diagram is
for an energy efficient bulb, and which is for an old fashioned, inefficient bulb?
Efficiency %
=
Useful energy output___
Total energy input
__________________________________
M Manser
x
100
__________________________________
13
Task 5: Complete the labels on the diagram below. The Sankey diagram shows the energy
changes in a power station. Calculate its efficiency.
Total energy wasted = _____________________________
Heat loss to the environment = 20J
Heat loss when the steam
cools to water = 40J
Chemical
energy in
= 100J
Heat and sound energy losses
in the generator = 5J
Useful electrical output = ______________
Efficiency
=
Useful energy output___
Total energy input
= ___________. =
100
P1b PRACTICE EXAMINATION QUESTIONS
1.
Foam is used to reduce energy loss from a home. Blocks of foam are put in the cavity
wall. They are placed between the outer and inner walls.
(a)
The foam in the cavity contains trapped air. Air is a poor conductor. Explain
how trapping the air reduces energy loss from the home.
........................................................................................................................ [1]
M Manser
14
(b)
What type of energy transfer does shiny foil reduce?
Put a
ring
conduction
(c)
around the correct answer.
convection
dispersion
radiation
[1]
Temperature and heat are measurements of different things. Complete the
sentences.
Temperature is a measurement of ................................................................
........................................................................................................................
Heat is a measurement of ..............................................................................
........................................................................................................................ [2]
(d)
A home owner decides to move his open fire from an outside wall into the
centre of his living room. This makes his fire more efficient.
(i)
The energy stored in 5 kg of coal is 160 MJ. This coal is burnt. It releases
40 MJ of heat into the room. Calculate the efficiency of the open fire.
The list of equations may help you.
...............................................................................................................
...............................................................................................................
answer ....................................................... [2]
(ii) Why is the fire more efficient in the centre of the room?
...............................................................................................................
............................................................................................................... [1]
[Total 7 marks]
M Manser
15
2.
(a)
Emma has single glazing in her house. Look at the diagram.
The warm air particles in the room bump into the glass. This energy is
transferred to the cool air outside.
Explain how this conduction happens. In your answer write about the
movement of particles.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................ [3]
(b)
Emma’s house costs a lot to heat. She decides to buy some insulation.
She chooses loft insulation and double glazing. Look at the table.
insulation
M Manser
cost to fit
loft insulation
£200
double glazing
£5000
money saved each
year in fuel bills
payback time
2 years
£250
16
(i)
She fits loft insulation. This saves her money on her fuel bills. Calculate
how much money this saves her in one year.
...............................................................................................................
answer £ .............................................. [1]
(ii)
Calculate the payback time for double glazing.
...............................................................................................................
answer ................................................ years [1]
(c)
Emma has a gas fire. Look at the
information about the fire. It shows
how many joules of energy are
transferred each second.
The efficiency of the fire is 75%.
Calculate the energy input for the fire.
Use the information in the diagram.
The list of equations may help you.
........................................................................................................................
........................................................................................................................
answer ........................................................ Joules [2]
[Total 7 marks]
M Manser
17
3.
Diane has two types of electric light bulbs in her house.
(a)
Diane finds this diagram from a website. It shows the energy into and out of a
filament bulb.
Calculate the efficiency of the filament bulb.
The list of equations may help you.
........................................................................................................................
........................................................................................................................
........................................................................................................................
answer .................................... [2]
(b)
Diane replaces all of the bulbs in her house with low energy bulbs. This costs
her £150. She now saves £30 each year on electricity. Calculate the payback
time for the energy saving bulbs.
........................................................................................................................
........................................................................................................................
........................................................................................................................
answer ................................ years [2]
[Total 4 marks]
M Manser
18
4.
(a)
Kevin wants to save money by insulating his house. He wants to reduce the
energy lost by conduction. Suggest one way he could reduce the energy lost by
conduction.
........................................................................................................................
........................................................................................................................ [1]
(b) To save more money Kevin replaces the light bulbs in his house with ‘lowenergy bulbs’.
One of the light bulbs uses 40 000 joules of electrical energy in one hour. It
gives out 10 000 joules of light energy in one hour. Calculate the efficiency of
the bulb. The list of equations may help you.
........................................................................................................................
........................................................................................................................
........................................................................................................................
answer ................................................................ [2]
(c)
Energy from Kevin’s central heating radiator warms his room by convection.
Explain how a convection current is produced and how it warms his room.
In your answer write about
•
the movement of air particles
•
changes in density
•
transfer of energy.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................ [3]
[Total 6 marks]
M Manser
19
1b Student Checklist
Tick column A when you have covered the statement in class.
Tick column B when you can complete questions on this concept and get the correct answer
Tick column MMA if you need additional help
P1b
I can:
KEEPING HOMES WARM
Explain the transfer of heat by conduction, convection
and radiation and understand how heat loss by these
methods can be reduced in the home situation
Explain conduction in terms of particles, convection in
terms of density changes and radiation in terms of
electromagnetic waves
Interpret cost saving data from this and can calculate
payback time.
Select and use the equation:
Efficiency =
useful energy output
total energy output
Draw, explain and complete Sankey diagrams to show
that energy is conserved.
A
B
MMA
Back to contents
M Manser
20
P1c: A SPECTRUM OF WAVES
TASK 1: Complete the crossword below on features and characteristics of waves
1
2
3
4
5
6
7
8
9
10
Down
2. Waves where the particles vibrate at right angles to the direction of energy flow
3. The number of oscillations per second
4. Waves where the particles vibrate in the same direction as that of the energy flow
6. The distance between two adjacent crests
9. The lowest point on a transverse wave
Across
1. The highest point on a transverse wave
5. Frequency x wavelength
7. Part of a longitudinal wave where the particles are further apart than usual
8. The distance between the rest position and the highest point on the wave
10. Waves transfer ______ from one place to another
M Manser
21
Task 2: The equation used to calculate wave speed will be given on the formula list. Use the
equation to create a triangle to help you to rearrange the equation. Then complete
the table to practise using this equation.
Wave speed = frequency x wavelength
Frequency (Hz)
4
2
Wavelength (m)
3
2
1.2 x 106
Wave speed (m/s)
Calculation
10
340
3 x 108
Task 3: Complete the bubble diagrams below by writing what you know about reflection,
refraction and diffraction. You may draw diagrams as well.
Reflection
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22
Refraction
Diffraction
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23
Task 4: Complete the brace map below by writing in the missing parts of the
electromagnetic spectrum. Below each name, write two facts, properties or uses.
G__________ rays:
 Highest f__________ and highest
e__________ waves.
 Used in m__________ to diagnose cancer.
__________ rays:
 W__________ slightly longer than gamma
waves.
 Used in m__________ to take pictures of
b__________.
U__________ v__________rays:
The Electromagnetic
Spectrum:
properties……
 All of the waves
travel at the same
________

All are transverse /
longitudinal

They can all travel
through a v_________
 Used in sun beds to cause t__________.
 Overexposure can cause __________ cancer.
__________ light:
 The only electromagnetic waves that can be
detected by the __________ __________.
 Used to take p__________ with everyday
cameras.
Infrared waves:
 Emitted by __________ objects.
 Detected by special cameras to produce
t__________ .
_________________:
 Used for __________ and international
__________.
 Absorbed strongly by __________
molecules.
Radiowaves:
 Used for __________ and __________
broadcasts. __________ by the ionosphere.
 Lowerst f__________ and lowest
e__________ so is the least dangerous.
M Manser
24
Task 5: Read the passage below carefully
Diffraction (taken from BBC Bitesize and Wikipedia)
When waves meet a gap in a barrier, they carry on through the gap. However, the waves spread
out to some extent into the area beyond the gap. This is diffraction.
The extent of the spreading depends on how the width of the gap compares to the wavelength of
the waves. Significant diffraction only happens when the wavelength is of the same order of
magnitude as the gap. For example:


a gap much larger than the wavelength causes little spreading and a sharp shadow eg light
through a doorway
a gap similar to the wavelength causes a lot of spreading with no sharp shadow eg sound
through a doorway
(a) Diffraction through a wide gap
Diffraction through a narrow gap
Diffraction - Higher tier
Diffraction reduces the quality (or resolution) of images seen in microscopes and telescopes. It
can cause rings or spikes around the image of the object being viewed.
The resolution of a given instrument is better when the size of the objective lens (the lens that
collects the light) is bigger. This is because there is less diffraction (diagram a.). If wavelength of
the light being observed increases, diffraction increases (diagram b), so the image will not be as
clear.
M Manser
25
P1c PRACTICE EXAMINATION QUESTIONS
1.
This question is about waves. Look at the diagram of a wave.
4
3
cm
B
2
1
C
0
A
1
3
E
5
7
cm
9
–1
–2
–3
D
–4
(a)
Which letter shows a trough? Choose from A, B, C, D or E.
answer ......................................................... [1]
(b)
The diagram is drawn to scale. What is the wavelength of the wave?
wavelength = ................................................... cm [1]
[Total 2 marks]
2.
This question is about waves.
Look at the diagram of a wave.
(a)
Complete the sentences about the wave.
Choose from the list.
amplitude
crest
frequency
wavelength
B
D
A
C
E
B is called the ............................................... .
The distance between A and D is called the ............................................. .
C is called the ............................................... . [3]
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26
(b) Look at the list of waves.
microwaves
infrared
radio
ultraviolet
(i)
Which wave is used in TV remote controls? Choose from the list.
............................................................................................................... [1]
(ii)
Which wave can cause skin cancer? Choose from the list.
............................................................................................................... [1]
[Total 5 marks]
3.
(a)
Radio waves can be transmitted over long distances. One method uses layers in
the Earth’s atmosphere.
(i)
Explain how the radio waves return to Earth.
...............................................................................................................
(ii)
Which part of the atmosphere causes the waves to return to Earth?
............................................................................................................... [2]
(b)
Microwaves are used for wireless communication. Look at this information
about microwaves
•
a microwave has a wavelength of 0.1 metres
•
it also has a frequency of 3 000 000 000 hertz.
Calculate the speed of the microwaves. The list of equations may help you.
........................................................................................................................
........................................................................................................................
........................................................................................................................
answer ............................................................................. metres per second [2]
[Total 4 marks]
M Manser
27
4.
This question is about different electromagnetic waves.
(a)
(i)
Louis cooks a large potato. The middle of the potato gets hot more
quickly if he uses a microwave oven instead of a conventional oven.
Explain why.
...............................................................................................................
............................................................................................................... [1]
(ii)
Microwaves are used for cooking. Write down one other use of
microwaves.
............................................................................................................... [1]
(b)
(i)
The Sun gives out ultraviolet rays. These rays affect the human body.
Write down two ways in which ultraviolet rays affect humans.
1 ............................................................................................................
2 ............................................................................................................ [2]
(ii)
Explain how we can reduce the effects of ultraviolet rays on the human
body.
...............................................................................................................
...............................................................................................................
...............................................................................................................
............................................................................................................... [2]
[Total 6 marks]
5.
This question is about waves.
(a)
radio
waves
M Manser
Look at the diagram of the electromagnetic spectrum.
microwaves
infrared
waves
visible
light
ultraviolet
light
X-rays
gamma
rays
28
(i)
Which type of wave is used to cook food?
............................................................................................................... [1]
(ii) Which type of wave is used by a TV remote control?
............................................................................................................... [1]
(iii) Ultraviolet waves can harm humans. What damage can ultraviolet waves
do to humans?
............................................................................................................... [1]
(b)
Look at the diagram of a wave.
B
D
A
C
E
Complete the sentences.
The crest is shown by letter ..........................................................................
The amplitude is shown by letter ..................................................................
The distance between letters A and D is called the ....................................... [3]
[Total 6 marks]
M Manser
29
1c Student Checklist
Tick column A when you have covered the statement in class.
Tick column B when you can complete questions on this concept and get the correct answer
Tick column MMA if you need additional help
P1c
I can:
A SPECTRUM OF WAVES
Describe the features of transverse waves i.e. crest and
trough, amplitude, wavelength and frequency.
Select and use the equation:
wave speed = frequency x wavelength
…..including a change of subject.
Explain reflection, refraction and diffraction. Explain
how the amount of diffraction depends on the size of
the opening and wavelength.
A
B
MMA
Name, in order of frequency or wavelength, the seven
parts of the electromagnetic spectrum. Relate the
receiver size to wavelength .
Describe how diffraction affects the minimum size of
telescopes and microscopes.
Back to contents
M Manser
30
P1d: LIGHT AND LASERS
Task 1: The diagrams below show reflection and refraction. Complete the labels.
This diagram shows the _____________ of a ray of _____________.
I_____________ ray
M_____________
i = angle of_____________
ray
i
r
normal
r = angle of_____________
ray
This diagram shows the _____________ of a ray as it travels into a glass_____________.
Air
Glass
i
angle of_____________
r
angle of_____________
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31
Task 2: When light is about to enter a substance which will cause its speed to decrease, it
may not be refracted. Complete the diagrams below by drawing the rays.
When a ray of light hits the
boundary between two
substances at right angles, it will
travel straight through
When a ray of light travels from
glass into air, its wavelength
increases and the ray bends
away from the normal
As the angle of incidence (at the
straight face of the glass block)
increases, the refracted ray will
eventually lie along the surface
of the block.
If the angle of incidence is
greater than the critical angle no
light will escape from the block.
Total internal reflection will
happen.
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32
Task 3: Complete the double bubble map to compare the use of light and
electrical signals to communicate
Communicating
with electrical
signals
Communicating
with light
Task 4: Complete the bubble diagrams below by writing what you know about lasers. You
may draw diagrams as well.
LASERS
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33
P1d PRACTICE EXAMINATION QUESTIONS
1.
This question is about electromagnetic waves.
(a)
A laser produces an intense beam of light waves. All the waves have the same
frequency and are in phase with each other.
(i)
Explain what is meant by an intense beam of light.
...............................................................................................................
............................................................................................................... [1]
(ii)
Explain what is meant by in phase with each other.
...............................................................................................................
............................................................................................................... [1]
(iii) CD players use laser beams. The light is reflected from a shiny surface.
This produces a digital signal. What is a digital signal?
...............................................................................................................
............................................................................................................... [1]
(b)
(i)
Louis cooks a large potato. The middle of the potato gets hot more
quickly if he uses a microwave oven instead of a conventional oven.
Explain why.
...............................................................................................................
............................................................................................................... [1]
(ii)
The walls of his microwave oven are made of shiny metal. The shiny
metal walls do not get hot. Explain why.
...............................................................................................................
............................................................................................................... [1]
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(iii) Microwaves are used for cooking. Write down one other use of
microwaves.
............................................................................................................... [1]
[Total 6 marks]
2.
Mirrors reflect light. Light can also be reflected along optical fibres without mirrors.
(a)
Complete the diagram to show a ray of light passing along the optical fibre and
out the other end.
[1]
(b)
Certain conditions are needed for total internal reflection. Complete the
sentences.
Light is reflected at the boundary between ............................... and
................................
The angle of incidence must be ............................... than the critical angle. [2]
[Total 3 marks]
3.
Optical fibres are made of glass. They carry infrared waves. These waves carry
information.
(a)
How does infrared radiation travel along optical fibres?
........................................................................................................................
........................................................................................................................ [1]
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(b)
Information can also be carried along copper wires. Using optical fibres can be
a better way to carry information. Suggest one reason why.
........................................................................................................................
........................................................................................................................ [1]
[Total 2 marks]
1d Student Checklist
Tick column A when you have covered the statement in class.
Tick column B when you can complete questions on this concept and get the correct answer
Tick column MMA if you need additional help
P1d
I can:
LIGHT AND LASERS
A
B
MMA
Describe the use of light in communication. Understand its
advantages and disadvantages when compared with radio
waves and electrical signals.
Understand the use of optical fibres for the transmission of
information and understand that these are an application of
total internal reflection (TIR)
Understand that TIR takes place when the angle of
incidence exceeds the critical angle and that this explains
how optical fibres work
Understand that lasers contain waves of the same frequency
that are in phase with one another
Explain the use of a laser beam in a CD player
Back to contents
M Manser
36
P1e COOKING AND COMMUNICATING USING WAVES
TASK 1: Complete the flow map to describe how a potato is cooked in an infrared oven.
Particles on the __________ absorb the
The kinetic energy is __________
energy, and their __________ energy
slowly through the solid potato.
increases
Much of the fuel’s energy is used to heat
Heating food this way generally takes
the __________ and the metal
__________ and is less __________
__________ in the oven.
than microwave cooking.
TASK 2: Complete the flow map to describe how a potato is cooked in a microwave oven.
Energy is absorbed by __________ and
The kinetic energy is __________
__________ molecules up to 2cm below
slowly through the solid potato, but has a
the skin.
shorter distance to travel to the _______.
None of the microwave energy is used to
Heating food this way generally takes
heat the __________ in the oven or the
__________ time and is more
container of the food.
__________ than oven cooking.
TASK 3: Read the articles below carefully.
Microwaves (physics.tutorvista.com)
These waves are initially considered to be of little use, but research has now allowed for
applications with long range communication and for cooking. The wave energy depends on the
frequency of the waves and it increases with increasing frequency (and decreases with
wavelength).
Microwave transmissions (http://www.revisionworld.com/gcse-revision/physics/electromagneticradiation/radio-waves-microwaves)
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Wireless technology uses microwaves and radio waves to transmit information. Advantages are:
 We can receive phone calls and email 24 hours a day
 No wiring is needed to connect laptops to the Internet, or for mobile phones or radio
 Communication with wireless technology is portable and convenient.
 Microwaves can be used to transmit signals over large distances if there are no obstacles
between to reflect or absorb the beam. Another way to say this is that the transmitter and
receiver are in line of sight (one can be seen from the other). This is why the transmitters are
positioned high up, often on tall microwave masts. They cannot be spaced so far apart that,
for example, hills or the curvature of the Earth stop the beam.
 Microwaves are used to send signals to and from satellites. The satellites can relay signals
around the Earth. Microwaves are used because they pass through the atmosphere and
through the ionosphere. The signals may be for television programmes, telephone
conversations, or monitoring the Earth (for example, weather forecasting).
When microwaves are transmitted from a dish the wavelength must be small compared to the
dish diameter to reduce diffraction – the spreading out of the beam. The dish is made of metal
because metal reflects microwaves well.
Mobile phones use microwave signals. The signals from the transmitting phones reflect off metal
surfaces and walls to communicate with the nearest transmitter mast. There is a network of
transmitter masts to relay the signals on to the nearest mast to the receiving phone.
Mobile phones have not been in widespread use for many years, so there is not much data about
the possible dangers of using them. The transmitter is held close to the user’s head so the
microwaves may have a small heating effect on the brain. There are questions about whether this
could be dangerous, or whether it is not large enough to be a problem. So far studies have not
found that users have suffered any serious ill effects. There may also be a risk to residents living
close to mobile phone masts.
Low-intensity microwave radiation, from mobile phone masts and handsets, may be a health risk,
but there is disagreement about this.
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P1e PRACTICE EXAMINATION QUESTIONS
1.
(a)
Microwaves are used to cook food in a
microwave oven.
Which substance in the food absorbs the
microwaves?
...........................................................................
................................................................ [1]
(b) Infrared waves are also used for cooking. Explain how infrared waves cook
food.
........................................................................................................................
........................................................................................................................
........................................................................................................................ [2]
(c)
(i)
Infrared waves can also be used to transmit data. State one other use of
infrared waves.
............................................................................................................... [1]
(ii) Two types of signal are used to transmit data. One type is digital. What is
the other type?
............................................................................................................... [1]
[Total 5 marks]
2.
This question is about electromagnetic waves.
(a)
Wireless technology uses electromagnetic waves for communication.
Look at the statements about wireless technology.
Put a tick ( ) in the box beside the statement if it is true.
Put a cross (
) in the box beside the statement if it is false.
Two have been done for you.
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[2]
(b)
Microwaves are used for wireless communication. Look at this information about
microwaves
•
a microwave has a wavelength of 0.1 metres
•
it also has a frequency of 3 000 000 000 hertz.
Calculate the speed of the microwaves. The list of equations may help you.
........................................................................................................................
........................................................................................................................
........................................................................................................................
answer ............................................................................. metres per second [2]
(c)
Some other electromagnetic waves are
•
ultraviolet
•
radio
•
X-rays.
What do you know about the speed of all electromagnetic waves?
........................................................................................................................ [1]
[Total 5 marks]
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3.
This question is about cooking.
(a)
Abbie uses microwaves to cook some rice. She puts the rice into a glass bowl.
She adds cold water to the rice. She puts the bowl in the microwave oven.
The oven has metal walls on the inside.
(i)
Why are the oven walls made of metal?
............................................................................................................... [1]
(ii) Why does she use a glass bowl?
............................................................................................................... [1]
(b)
Abbie cooks a curry in the microwave oven. The water in the curry absorbs the
microwaves.
(i)
Explain how this affects the water particles.
...............................................................................................................
............................................................................................................... [1]
(ii)
How does the centre of the food then get hot?
...............................................................................................................
............................................................................................................... [1]
(c)
M Manser
Abbie cooks some food in pans on a hob. She uses cooking oil in one pan. She
uses water in the other. The cooking oil and water are at high temperatures.
They are in identical pans. Look at the diagram.
41
She lets them both cool down. The cooking oil cools to room temperature more
quickly. Look at the information below.
starting
temperature in
°C
time taken to
cool to room
temperature in
minutes
mass of liquid
in kg
specific heat
capacity in
J/kg °C
cooking oil
120
25
0.5
860
water
100
60
0.5
4200
liquid
Why does the cooking oil cool quicker than the water?
........................................................................................................................
........................................................................................................................ [1]
[Total 5 marks]
4.
This question is about communication. Mobile phones use wireless
technology and microwaves.
(a)
This wireless technology can be useful. Suggest two reasons why.
1 ........................................................................................................
2 ................................................................................................... [2]
(b)
These microwave signals may cause problems. Suggest two
problems.
1 .....................................................................................................................
2 ..................................................................................................................... [2]
[Total 4 marks]
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P1e Student Checklist
Tick column A when you have covered the statement in class.
Tick column B when you can complete questions on this concept and get the correct answer
Tick column MMA if you need additional help
P1e
I can:
COOKING AND COMMUNICATING USING WAVES
A
B
MMA
Compare cooking using microwaves with using
infrared radiation
Describe how microwaves and infrared transfer
energy
Relate the energy of microwaves and infrared to
their frequency
Describe what affects the transmission of
microwaves over large distances and how the
problems can be overcome.
Describe why there may or may not be dangers
to users of mobile phones or residents near the
site of transmitter.
Describe how scientific research provides
conflicting evidence of the dangers and how risk
and benefit must be balanced.
Back to contents
M Manser
43
P1f DATA TRANSMISSION
TASK 1: Complete the crossword on infrared (IR) radiation and its many uses
Down
2. IR waves are sent this way
to create a digital signal
4. Short __________ infrared
are not hot so cannot be felt
by the skin
7. These alarms detect IR
emitted by the human body
Across
1. Using these fibres, IR
waves can be sent over long
distances
3. Electromagnetic waves
with a longer wavelength
than IR
5. This type of energy
increases when the energy from IR waves is absorbed
6. IR waves can travel around corners
8. _______ wavelength IR waves can be felt by the skin since they produce heat.
9. The image produced by detecting IR waves radiated from an object
10. This device uses IR waves for cooking
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TASK 2: Complete the “double bubble” map to compare and contrast digital and analogue
signals.
Digital
Communication
Analogue
Communication
TASK 3: Read the information below on digital signals and multiplexing. (Bitesize)
Optical fibres
An optical fibre is a thin rod of high-quality glass. Very little light is absorbed by the glass.
Light getting in at one end undergoes repeated total internal reflection, even when the fibre is
bent, and emerges at the other end.
Information such as computer data and telephone calls can be converted into electrical signals.
These can be carried through
cables, or transmitted as
microwaves or radio waves.
However, the information can
also be converted into either
visible light signals or infrared
signals, and transmitted by
optical fibres.
Optical fibres can carry more information than an ordinary cable of
the same thickness. The signals in optical fibres do not weaken as
much over long distances as the signals in ordinary cables.
They can carry more data through the same cable because of
multiplexing. This is where several digital signals are interleaved
or carried together without being mixed.
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P1f PRACTICE EXAMINATION QUESTIONS
1.
(a)
Mel is on holiday. She has taken her laptop computer with
her. She uses her laptop to send emails. The laptop uses
wireless technology.
Write about the advantages of wireless technology.
................................................................................................................................
................................................................................................................................
.......................................................................................................................... [2]
(b) At home Mel uses a mouse to control her laptop. The mouse uses infrared
radiation.
(i)
She points her mouse away from the laptop. It still works. Why?
Put a tick ( ) in the box next to the correct answer.
The infrared radiation is absorbed by the walls of her room.
The infrared radiation is digitalised by the walls of her room.
The infrared radiation is reflected by the walls of her room.
The infrared radiation is refracted by the walls of her room.
(ii)
[1]
Write down one other household device controlled using infrared
radiation.
............................................................................................................... [1]
(iii) Infrared radiation can be transmitted along an optical fibre.
Which point shows total internal reflection?
Choose from:
A
B
C
D
answer ....................................................... [1]
M Manser
[Total 5 marks]
46
2.
Infrared waves are used for communication. Complete the sentences. Two sentences
have been done for you. Choose your answers from the list.
Each answer can be used once, more than once or not at all.
analogue
burglar alarms
digital
calculators
reflection
diffraction
refraction
TV remote controls use infrared waves. They can send waves as
....................................................... or digital signals. Infrared sensors are used in
...................................................... . Infrared waves are sent through optical fibres. These
waves pass along the fibre by total internal ............................................... . [Total 3 marks]
3.
This question is about communications.
(a)
(i)
Look at the diagram of an optical fibre.
A ray of light travels in the fibre. It comes out at the other end. Describe
how the light travels through the fibre. You may draw on the diagram to
help your answer.
...............................................................................................................
...............................................................................................................
............................................................................................................... [2]
(ii)
Optical fibres are used to transmit information. Information can be carried
by analogue or digital signals. Write down one difference between
analogue and digital signals.
...............................................................................................................
............................................................................................................... [1]
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(b)
Digital signals carry more information than analogue signals. This makes the
picture on a digital TV better, with less interference.
(i)
Explain why more information can be carried.
...............................................................................................................
............................................................................................................... [1]
(ii)
Explain why there is less interference on a digital TV.
...............................................................................................................
............................................................................................................... [1]
[Total 5 marks]
1f Student Checklist
Tick column A when you have covered the statement in class.
Tick column B when you can complete questions on this concept and get the correct answer
Tick column MMA if you need additional help
P1f
I can:
DATA TRANSMISSION
A
B
MMA
Explain how infrared can be used as a short range
digital signal
Understand the advantages of digital signals over
analogue signals
Describe how light is transmitted through optical
fibres including multiplexing.
Describe the differences between analogue and
digital signals
Back to contents
M Manser
48
P1g WIRELESS SIGNALS
TASK 1
P1g - PRACTICE EXAMINATION QUESTIONS
P1f Student Checklist
Tick column A when you have covered the statement in class.
Tick column B when you can complete questions on this concept and get the correct answer
Tick column MMA if you need additional help
P1g
I can:
WIRELESS SIGNALS
A
B
MMA
Recognise that radiation used in communication
can be refracted and understand the uses of wireless
technology
Recognise the use of wireless technology in radio,
mobile phones and laptop computers
Recognise that radio stations may interfere with
one another.
Understand that radio waves may be reflected,
refracted and diffracted and the effects of these
upon wireless reception
Describe the advantages and disadvantages of DAB
radio
Back to contents
P1h STABLE EARTH
TASK 1
P1f - PRACTICE EXAMINATION QUESTIONS
P1f Student Checklist
Tick column A when you have covered the statement in class.
M Manser
49
Tick column B when you can complete questions on this concept and get the correct answer
Tick column MMA if you need additional help
P1h
I can:
STBLE EARTH
A
B
MMA
Describe the production of seismic waves during
earthquakes
State the existence of and state the properties of
two types of seismic waves (P & S)
Describe the use of seismic waves in providing
evidence of the Earth’s structure
Explain the effect of skin pigment on the risk of
cancer
Calculate how long a person may safely spend in the
sun using SPF
Describe how the ozone layer protects the Earth from
ultraviolet radiation and the damaging effect of CFCs
Describe how scientists verified their measurements
of ozone depletion and how the ozone hole over
Antarctica needed international agreements.
Describe the production of seismic waves during
earthquakes
Back to contents
M Manser
50