Year 11
Edexcel Science
iGCSE Physics
V. Magnetism and
Electromagnetism
2019-2020
Name:________________
Physics Teacher:______________
House
CG
Test Score
Specification Checklist
6.01
use the following units: ampere (A), volt (V) and watt (W)
6.02
know that magnets repel and attract other magnets and attract magnetic substances
6.03
describe the properties of magnetically hard and soft materials
6.04
understand the term magnetic field line
6.05
know that magnetism is induced in some materials when they are placed in a magnetic
field
6.06
practical: investigate the magnetic field pattern for a permanent bar magnet and
between two bar magnets
6.07
describe how to use two permanent magnets to produce a uniform magnetic field
pattern
6.08
know that an electric current in a conductor produces a magnetic field around it
6.09
describe the construction of electromagnets
6.10
draw magnetic field patterns for a straight wire, a flat circular coil and a
solenoid when each is carrying a current
6.11
know that there is a force on a charged particle when it moves in a magnetic
field as long as its motion is not parallel to the field
6.12
understand why a force is exerted on a current-carrying wire in a magnetic field, and
how this effect is applied in simple d.c. electric motors and loudspeakers
6.13
use the left-hand rule to predict the direction of the resulting force when a wire
carries a current perpendicular to a magnetic field
6.14
describe how the force on a current-carrying conductor in a magnetic field changes
with the magnitude and direction of the field and current
Magnetism and Electromagnetism – Science (Physics)
2
Key Words
Key Word
Image
Definition
Alternating
Current (a.c.)
Current that repeatedly changes direction. This is what
comes out of your plug socket.
Circuit Breaker
A switch linked to an electromagnet that performs the
same function as a fuse but more quickly. Can be reset
and reused.
Direct Current
(d.c.)
Current that travels in a single direction. This is what is
used in batteries and most computers/phones.
Electromagnet
A soft iron core wrapped in wire. When current flows
through the coil it becomes magnetic.
Field Line
An indication of the strength and direction of the
magnetic field. The denser the lines the stronger the
field.
Hard/Soft
Magnetic
Material
A measure of how quickly a material loses its magnetic
properties over time. Soft materials become nonmagnetic much faster than hard.
Iron Core
The centre of an electromagnet. It boosts the power of a
solenoid.
Left Hand Rule
(Motor Effect)
The relationship between magnetic field direction,
electrical current in a wire and the force on the wire
while inside a magnetic field.
Magnetic Field
An area where other magnetic objects experience a
force of attraction and repulsion.
Magnetic
Material
Permanent
Magnet
Right Hand
Rule
Solenoid
A material that is attracted to a magnet or can be
magnetic. E.g. Iron, Nickel, Steel, Cobalt.
A hard magnetic material that will not lose its magnetism
over time.
The relationship between current in a wire and the shape
of the field around it.
A coil of wire with electricity running through it. Produces
a magnetic field similar to that of a bar magnet.
Magnetism and Electromagnetism – Science (Physics)
3
1: Magnetic Fields
Knowledge and Understanding Recap Quiz
Use the knowledge you have gained since Shell to answer the following questions
1. What is the mass of an object that weighs 2N on Earth?
………………
(2)
…………………………………………………………………………………………
…………………………………………………………………………………………
(2)
2. What is the law of conservation of energy?
3. What is the definition of a longitudinal wave?
…………………………………………………………………………………………
…………………………………………………………………………………………
(2)
4. What is the purpose of the control rods in a nuclear reactor?
…………………………………………………………………………………………
…………………………………………………………………………………………
(2)
5. If a 50N box has a base area of 3m2, what pressure is it putting down on the ground?
………………
(3)
6. What is the definition of frequency?
…………………………………………………………………………………………
…………………………………………………………………………………………
(1)
7. A planet orbits the Sun in 567 days. It has an orbital radius of 70 000km. What is the
orbital speed of the planet?
(3)
Score [
Magnetism and Electromagnetism – Science (Physics)
/15]
4
Learning Outcomes:
1. Define what is meant by a ‘magnetic field’
2. Describe an experiment to investigate the magnetic field pattern around a
bar magnet
3. Sketch the shape and direction of the magnetic field around a bar magnet
including the direction.
Magnets and Magnetic Fields.
Key Ideas
1. Magnets are able to attract objects made from magnetic materials (e.g. iron, steel, nickel
and cobalt)
2. Magnetism is induced in these magnetic materials when they are placed in a magnetic
field.
3. Permanent magnets are made from magnetically hard materials (e.g. steel) which
keep their magnetism once they have been magnetised.
4. The strongest part of a magnet are its poles, North and South,
5. Around every magnet there is a region of space where we can detect magnetism (where
magnetic materials will be affected).
6. This is called the magnetic field and in a diagram we represent this with magnetic field
lines.
7. The magnetic field lines should always point from north to south.
Magnetism and Electromagnetism – Science (Physics)
5
V1: Plotting Magnetic Field Lines
Health and Safety Check!
In this investigation you are going to use a compass
to map the field lines around a bar magnet.
Keep any strong magnets
away from electronic
devices.
In what directions do the field lines point?
……………………………………………………………..
Method
1.
2.
3.
4.
5.
6.
Place your bar magnet in the centre of the next page and draw around it.
Place a compass at one pole of the bar magnet.
Draw a ‘dot’ to show there the compass is pointing,
Move the compass so the opposite end of the needle is pointing to the dot,
Repeat steps 3 and 4 until to reach the other pole of the magnet.
Do this procedure at least 5 times from different points on the pole of the magnet.
*Tip, try to be as accurate as possible when drawing your dots*
7. Join up your dots to create your field line!
Magnetism and Electromagnetism – Science (Physics)
6
Draw around your magnet and plot your field lines on this page.
Magnetism and Electromagnetism – Science (Physics)
7
Magnetic Field around a Bar Magnet
Key Ideas
1. Magnetic field lines never cross
2. We illustrate stronger magnets by sketching the field lines closer together.
3. Magnetic field lines always point from the north pole to the south pole of the magnet.
Magnetism and Electromagnetism – Science (Physics)
8
2: Attraction and Repulsion
Knowledge and Understanding Recap Quiz
Use the knowledge you have gained since Shell to answer the following questions
1. How much charge passes through a point in a circuit if a current of 5A flows of 35
seconds?
………………
(3)
…………………………………………………………………………………………
…………………………………………………………………………………………
(2)
2. What is the principle of moments?
3. What is 17K in oC?
…………………………………………………………………………………………
…………………………………………………………………………………………
(1)
4. What are the three types of ionising radiation?
…………………………………………………………………………………………
…………………………………………………………………………………………
(3)
o
5. A light ray is refracted through a block. An angle of incidence of 50 produces an angle
of refraction of 37o. What is the refractive index of the block?
………………
(3)
6. What is meant by the absolute brightness of a star?
…………………………………………………………………………………………
…………………………………………………………………………………………
(1)
7. Sketch the magnetic field around the bar magnet below:
(2)
Score [
Magnetism and Electromagnetism – Science (Physics)
/15]
9
Learning Outcomes:
1. Describe the conditions under which magnets repel or attract
2. Investigate the shape of the magnetic field during attraction and repulsion
3. Describe the shape of a uniform magnetic field and under what conditions it
happens
Attraction and Repulsion
Key Ideas
1. If two poles of permanent magnets are put next to each other they will either repel or
attract.
2. Similar poles (north-north or south-south) will repel each other.
3. Opposite poles (north-south) will attract each other.
Magnetism and Electromagnetism – Science (Physics)
10
V2: Plotting Magnetic Field Lines (Attract/Repel)
Health and Safety Check!
In this investigation you are going to use a compass
to map the field lines between two magnets (once
for attraction and once for repulsion)
Keep any strong magnets
away from electronic
devices.
What poles should be facing each other for repulsion?
……………………………………………………………..
What poles should be facing each other for attraction?
……………………………………………………………..
Method
1. Place your two bar magnets in the centre of the next page and draw around them.
[Make sure the correct poles are facing each other].
2. Draw a ‘dot’ to show there the compass is pointing,
3. Move the compass so the opposite end of the needle is pointing to the dot,
4. Repeat steps 3 and 4 until to reach the other magnet or the end of the page.
5. Do this procedure at least 5 times from different points on the pole of the magnet.
*Tip, try to be as accurate as possible when drawing your dots*
6. Join up your dots to create your field line!
Magnetism and Electromagnetism – Science (Physics)
11
Draw around your magnet and plot your field lines on this page [ATTRACTION]
Magnetism and Electromagnetism – Science (Physics)
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Draw around your magnet and plot your field lines on this page [REPULSION]
Magnetism and Electromagnetism – Science (Physics)
13
Magnetic Fields – Attraction and Repulsion
Key Ideas
1. When magnets are attracting we get a uniform magnetic field between the magnets.
2. A uniform magnetic field is comprised of straight, parallel lines which are evenly
spaced.
3. When magnets are repelling we get an area between the magnets where there are no
magnetic field lines at all.
Magnetism and Electromagnetism – Science (Physics)
14
Worksheet: Magnetic Field Lines
For all of the situations below, can you sketch the magnetic field? Don’t forget to include
direction!
STRETCH
STRETCH
Magnetism and Electromagnetism – Science (Physics)
15
3. Current, Magnetic Fields and Electromagnets
Knowledge and Understanding Quiz
Use the knowledge you have gained since Shell to answer the following questions
1. What is the acceleration of a 50kg object when experiences an unbalanced force of
650N?
………………
2. On the image below add:
a. The shape of the magnetic field
b. The direction of the magnetic field
(3)
(1)
(1)
3. What is the definition of current?
…………………………………………………………………………………………
…………………………………………………………………………………………
(2)
4. If a submarine is 350m below sea level. What is the pressure experienced by the
submarine due to the sea water? [density of sea water is 1100kg/m3]
………………
(3)
5. What two conditions are required for TIR (total internal reflection) to occur?
…………………………………………………………………………………………
…………………………………………………………………………………………
Score [
Magnetism and Electromagnetism – Science (Physics)
(2)
/12]
16
Learning Outcomes:
1. Understand that when an electric current passes through a conductor it
produces a magnetic field around the conductor.
2. Sketch the shape and direction of the magnetic field around a conducting
wire, flat circular coil and a solenoid.
3. Describe the construction of an electromagnet and explain what changes can
be made to alter its strength.
Magnetic Fields around a current carrying wire
Key Ideas
1. When current passes through a wire, a magnetic field is created around the wire. This is
called electromagnetism.
2. The field around a wire is a circular shape.
3. We can determine the direction of the field using the right hand grip rule.
Magnetism and Electromagnetism – Science (Physics)
17
Health and Safety Check!
V3: Demo – Current and Field Shapes
Your teacher is going to demonstrate the shape of the
fields around a flat circular coil and a solenoid.
Circular coils and solenoid
can get hot during use.
Do not touch.
In the space below make sure to sketch the direction and
shape of the magnetic field you observe.
It is also important to include the direction of the current in your diagram.
Flat Circular Coil
Solenoid
How could you increase the strength of the
magnetic field?
How could you increase the strength of the
magnetic field?
…………………………………………………..
…………………………………………………..
…………………………………………………..
…………………………………………………..
…………………………………………………..
…………………………………………………..
…………………………………………………..
…………………………………………………..
Magnetism and Electromagnetism – Science (Physics)
18
V4: Building and Testing an Electromagnet
Health and Safety Check!
In this investigation you are going to build a simple
electromagnet using some insulated wire and an iron
nail.
Electromagnet should not
be left on for extended
periods of time as it will
get too hot.
You will then test the effect of increasing the number of
turns in your coil and increasing the current through your wire.
Method 1 – Number of coils
1.
2.
3.
4.
5.
6.
Wrap your insulated wire around your iron nail 10 times.
Connect your wire to a power supply as per the diagram below.
Set the power supply to 2V
Attempt to pick up some paper clips, record how many you pick up.
Increase the number of coils by 5.
Repeat steps 4 and 5 until you reach 40 coils.
Method 2 – Current
1. Wrap your insulated wire around your iron nail 20 times.
2. Connect your wire to a power supple as per the diagram below but now add an
ammeter in series.
3. Set the power supply to 1V
4. Take a reading of current from the ammeter.
5. Attempt to pick up some paper clips, record how many you pick up.
6. Increase the voltage on the power supply by 1V.
7. Repeat steps 4-6 until you reach 6V.
Magnetism and Electromagnetism – Science (Physics)
19
Results
Method 1 – Number of coils
Number of coils
Number of Paperclips
10
15
20
25
30
35
40
How did the number of coils affect the strength of your electromagnet?
…………………………………………………………………………………………………..
…………………………………………………………………………………………………..
Method 2 – Number of coils
Voltage [V]
Current [A]
Number of Paperclips
1
2
3
4
5
6
How did the current through the coil affect the strength of your electromagnet?
…………………………………………………………………………………………………..
…………………………………………………………………………………………………..
Magnetism and Electromagnetism – Science (Physics)
20
The Electromagnet
Key Ideas
1. An electromagnet is made by wrapping a coil of wire around an iron core and passing a
current through it.
2. The core will then become magnetic as long as the current is flowing.
3. The core must be made of a magnetically soft material such as iron.
4. If you increase the number of turns in the coil around the core you make the
electromagnet stronger.
5. If you increase the size of the current passing through the wire you also make the
electromagnet stronger.
Magnetism and Electromagnetism – Science (Physics)
21
4. Flemings’ Left Hand Rule
Knowledge and Understanding Quiz
Use the knowledge you have gained since Shell to answer the following questions
1. Sketch the shape and direction of the magnetic field around the wire below.
(2)
2. Sketch a transverse wave below.
a. Label on the wavelength
b. Label on the amplitude
(1)
(1)
(2)
3. How does the crumple zone on a car reduce the force on a passenger during a
collision?
…………………………………………………………………………………………
…………………………………………………………………………………………
(1)
4. Sketch the I-V graph for a resistor.
(3)
5. What is the equation linking kinetic energy, mass and velocity?
…………………………………………………………………………………………
…………………………………………………………………………………………
Score [
(1)
/11]
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
……………………………………………………………………………………………………………
Magnetism and Electromagnetism – Science (Physics)
22
Learning Outcomes:
1. Use the left hand rule to predict the direction of movement of a current
carrying wire when it is perpendicular to a magnetic field.
2. Describe ways to increase the force this wire experiences.
3. Understand that any charged particle will experience a force when moving
in a magnetic field except if travelling parallel to that field.
Flemings’ Left Hand Rule
Key Ideas
1. When a charged particle (such as an electron in a wire) moves through a magnetic field
it experiences a force (unless it is travelling parallel to the field).
2. This is known as the motor effect.
3. When the direction of the current and the magnetic field are perpendicular to one
another we can predict the direction of this force.
4. We do this using the left hand rule.
a. Thumb – direction of force
b. First Finger – direction of field
c. Second finder – direction of current.
Magnetism and Electromagnetism – Science (Physics)
23
V5: Investigating Force on a wire
Health and Safety Check!
In this investigation you are going to investigate what
factors affect the force experienced by a current
carrying wire in a magnetic field.
Do not leave current
flowing through the wire
on for too long – wire
may overheat.
What two factors are you going to investigate?
1. ……………………………………………..
2. ……………………………………………..
In this investigation the method is written in the questions
and will be underlined so it is vital that you work methodically through these.
Yoke
Magnets
North
-
+
Wire
V5: Method and questions
1. Set up your equipment as per the diagram above. Connect an Ammeter in series with the
wire. Do not turn on the power supply.
What happens to the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
2. Set your power supple to 1V and switch it on.
Record the reading on the Ammeter: …………..
What happened to the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
3. Increase the voltage of the power supply to 2V
Record the reading on the Ammeter: …………..
What happened to the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
Magnetism and Electromagnetism – Science (Physics)
24
4. What is the link between current in the wire and the force on the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
5. To increase the strength of the magnetic field add another magnet to each side of the yoke.
What happened to the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
6. To increase the strength of the magnetic field further add two more magnets.
What happened to the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
7. What is the link between the strength of the magnetic field and the force on the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
8. Drawing on your knowledge from electromagnetism, can you suggest another way to
increase the force on the wire?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
Magnetism and Electromagnetism – Science (Physics)
25
Worksheet – Electromagnetism and Left Hand Rule
Q1.The diagram shows apparatus set up by a student.
Closing the switch creates a force that acts on the wire XY.
(a)
(i)
Explain why a force acts on the wire XY when the switch is closed.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(3)
(ii) The force causes the wire XY to move.
Draw an arrow on the diagram above to show the direction in which the wire XY
will move.
(1)
(iii)
State the effect that this experiment demonstrates.
...............................................................................................................
(1)
(b) The student replaced the battery with a low frequency alternating current (a.c.) power
supply.
The student closed the switch.
(i)
Describe the movement of the wire.
...............................................................................................................
(1)
Magnetism and Electromagnetism – Science (Physics)
26
(ii)
Give a reason for your answer to part (i).
...............................................................................................................
...............................................................................................................
...............................................................................................................
(1)
Q2.(a)
Some people wear magnetic bracelets to relieve pain.
Figure 1 shows a magnetic bracelet.
There are magnetic poles at both A and B.
Part of the magnetic field pattern between A and B is shown.
Figure 1
What is the pole at A? ...........................................
What is the pole at B? ...........................................
(1)
(b)
Figure 2 shows two of the lines of the magnetic field pattern of a currentcarrying wire.
Figure 2
The direction of the current is reversed.
What happens to the direction of the lines in the magnetic field pattern?
.......................................................................................................................
(1)
Magnetism and Electromagnetism – Science (Physics)
27
(c)
Fleming’s left-hand rule can be used to identify the direction of a force acting
on a current-carrying wire in a magnetic field.
(i)
Complete the labels in Figure 3.
Figure 3
(2)
(ii)
Figure 4 shows:
•
the direction of the magnetic field between a pair of magnets
•
the direction of the current in a wire in the magnetic field.
Figure 4
In which direction does the force on the wire act?
..............................................................................................................
(1)
(iii)
Suggest three changes that would decrease the force acting on the
wire.
1 ..........................................................................................................
2 ..........................................................................................................
3 ..........................................................................................................
(3)
Magnetism and Electromagnetism – Science (Physics)
28
(d)
Figure 5 shows part of a moving-coil ammeter as drawn by a student.
The ammeter consists of a coil placed in a uniform magnetic field.
When there is a current in the coil, the force acting on the coil causes the coil
to rotate and the pointer moves across the scale.
Figure 5
(i)
The equipment has not been set up correctly.
What change would make it work?
..............................................................................................................
..............................................................................................................
(1)
(ii)
Figure 6 shows the pointer in an ammeter when there is no current.
Figure 6
What type of error does the ammeter have?
..............................................................................................................
(1)
Score [
Magnetism and Electromagnetism – Science (Physics)
/18]
29
5: Motors and Loudspeakers
Knowledge and Understanding Recap Quiz
Use the knowledge you have gained in the topic so far to answer the following questions.
1. Sketch the shape and direction of the magnetic field around the following:
(4)
2. What is a uniform magnetic field?
…………………………………………………………………………………………
…………………………………………………………………………………………
(2)
3. Give one way to decrease the strength of an electromagnet.
…………………………………………………………………………………………
…………………………………………………………………………………………
(1)
4. When will a charged particle not experience a force when in a magnetic field?
…………………………………………………………………………………………
…………………………………………………………………………………………
(1)
5. Label the quantities represented by the fingers in Fleming’s Left hand rule.
(3)
6. In what direction will the wire move in each of the examples below:
(3)
Score [
Magnetism and Electromagnetism – Science (Physics)
/14]
30
Learning Outcomes:
1. Describe how a motor works using the left hand rule.
2. Describe how a loudspeaker works using the left hand rule.
V6: Demo - The Motor
Health and Safety Check!
B
Do not leave current
flowing through the wire
on for too long –
wire/motor may overheat.
C
A
D
Key Ideas
1. How is a Motor working?
 Current flows in the wire/coil.
 This creates a magnetic field around the wire/coil.
 This magnetic field interacts with the field from the permanent magnet.
 This produces a force on the wire/coil which moves the wire/coil.
2. In the diagram above:
 AB experiences upward force
 CD experiences downward force
 The coil rotates (clockwise)
3. The split-ring commutator changes the direction of the current every half turn as it
spins. This reverses the direction of the forces, allowing the coil to continue spinning.
Magnetism and Electromagnetism – Science (Physics)
31
V7: Demo - The Loudspeaker
Health and Safety Check!
Do not leave current
flowing through the foil
on for too long –
foil may overheat.
Very strong magnet.
Keep away from phones
and pacemakers.
Key Ideas
How is a loudspeaker working?







An alternating current from the source passes though the coils in the speaker.
This current is constantly changing direction and magnitude
This current creates a magnetic field around the coil
This field interacts with the magnetic field from the permanent magnets
Creating a constantly changing force on the coil.
This causes the coil to vibrate in and out as the direction of the force changes,
moving the cone
The cone causes vibrations which we hear as sound waves.
Magnetism and Electromagnetism – Science (Physics)
32
Worksheet – Loudspeakers and Motors
Q1. The photograph shows a simple d.c. electric motor.
(a) When the switch is closed the coil spins.
Explain why this happens.
(3)
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
(b) (i) Describe two ways to increase the speed of rotation of the coil in this motor.
(2)
1.................................................................................................................................................
2.................................................................................................................................................
(ii) Suggest how to make the coil spin in the opposite direction.
(1)
.............................................................................................................................................
.............................................................................................................................................
Magnetism and Electromagnetism – Science (Physics)
33
Q2. In the radio, sound is produced by a loudspeaker.
The diagram shows the construction of a loudspeaker.
Describe how a loudspeaker uses an electrical supply to produce sound waves.
(5)
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
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Score [
Magnetism and Electromagnetism – Science (Physics)
/11]
34
Stretch Activity – The Electric Bell
Below is a diagram on an electric bell circuit.
Using the knowledge you have gained in the topic, can you explain how the bell works?
You will need to link to hard/soft materials, electromagnets and magnetism.
…………………………………………………………………………………………………..
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Magnetism and Electromagnetism – Science (Physics)
35
Stretch Activity – The Circuit Breaker
Below is a diagram of a circuit breaker.
Using the knowledge you have gained in the topic, can you explain how the circuit
breaker works? You will need to link to hard/soft materials, electromagnets and
magnetism.
…………………………………………………………………………………………………..
…………………………………………………………………………………………………..
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Magnetism and Electromagnetism – Science (Physics)
36
Magnetism and
Electromagnetism
Past Paper
Questions
Magnetism and Electromagnetism – Science (Physics)
37
Q1.
The photograph shows a plotting compass and a small bar magnet.
(a) Describe how you should use this apparatus to investigate the magnetic field pattern
of the bar magnet.
(3)
.............................................................................................................................................
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(b) Add the magnetic field pattern of the bar magnet to the diagram below.
(3)
(Total for question = 6 marks)
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Q2.
(a) State what is meant by the term magnetic field line.
(1)
.............................................................................................................................................
.............................................................................................................................................
(b) The diagram shows a cross-section through a wire placed between two magnetic poles.
The wire carries electric current into the page at X.
The shape of the magnetic field is shown.
(i) Add arrows to any two lines to show the direction of the magnetic field.
(1)
(ii) Draw an arrow on the diagram to show the direction of the force on the wire.
Label this arrow F.
(2)
(c) Describe the magnetic field in the region inside the dotted square.
(2)
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.............................................................................................................................................
.............................................................................................................................................
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(Total for question = 6 marks)
Magnetism and Electromagnetism – Science (Physics)
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Q3.
A magnetic field pattern can be shown using lines.
(a) The diagram shows some magnetic field patterns.
Which pattern shows a uniform magnetic field? Explain your answer.
(2)
Pattern........................................................................................................................................
Explanation................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
(b) Explain how to produce a uniform magnetic field.
(3)
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.............................................................................................................................................
.............................................................................................................................................
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(Total for question = 5 marks)
Magnetism and Electromagnetism – Science (Physics)
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Q4.
Some students are investigating a simple electric motor.
(a) When the switch is closed the coil spins on the axle.
State why.
(2)
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
(b) State two changes that would make the motor spin faster.
(2)
1 ................................................................................................................................................
.............................................................................................................................................
2 ................................................................................................................................................
.............................................................................................................................................
(Total for question = 4 marks)
Magnetism and Electromagnetism – Science (Physics)
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Q5.
The diagram shows a piece of card and two wide bar magnets.
(a) (i) Add to the diagram to show the shape and direction of the magnetic field
pattern between the magnets.
(3)
(ii) Describe how to investigate the shape and direction of the magnetic field
between the magnets.
(3)
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
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(b) A metal rod, X Y, is placed in a magnetic field as shown.
Wires from a cell are connected to the ends of the rod so that there is a current
from X to Y.
(2)
Describe the effect on the rod.
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
(Total for question = 8 marks)
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Magnetism and
Electromagnetism
Spec Point
Notes
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Magnetism and Electromagnetism Specification Notes
6.01
use the following units: ampere (A), volt (V) and watt (W)
6.02
know that magnets repel and attract other magnets and attract magnetic substances
6.03
describe the properties of magnetically hard and soft materials
6.04
understand the term magnetic field line



6.05
Around every magnet there is a region of space where we can detect magnetism (where
magnetic materials will be affected).
This is called the magnetic field and in a diagram we represent this with magnetic field
lines.
The magnetic field lines should always point from north to south.
know that magnetism is induced in some materials when they are placed in a magnetic
field
When magnetic materials
are bought near or touch the pole of
a strong or permanent magnet, they
become magnets. This magnetic
character is induced on the objects
and it is removed when the permanent
magnet is removed.
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6.06
practical: investigate the magnetic field pattern for a permanent bar magnet and
between two bar magnets
[see practical’s on pages 6 and 11]
Single bar magnet:
Between magnets:
6.07
describe how to use two permanent magnets to produce a uniform magnetic field
pattern
A uniform magnetic field is comprised of straight, parallel lines which are evenly
spaced.
6.08
know that an electric current in a conductor produces a magnetic field around it
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6.09
describe the construction of electromagnets
6.10
draw magnetic field patterns for a straight wire, a flat circular coil and a
solenoid when each is carrying a current
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6.11
know that there is a force on a charged particle when it moves in a magnetic
field as long as its motion is not parallel to the field
6.12
understand why a force is exerted on a current-carrying wire in a magnetic field, and
how this effect is applied in simple d.c. electric motors and loudspeakers
Please see pages 31 and 32 for model answers for this spec point.
6.13
use the left-hand rule to predict the direction of the resulting force when a wire
carries a current perpendicular to a magnetic field
6.14
describe how the force on a current-carrying conductor in a magnetic field changes
with the magnitude and direction of the field and current

If you increase the magnitude of the current through a wire or the size of the
magnet being used, you increase the force on the wire.

If you change the direction of the current or reverse the poles of the magnet,
you change the direction of the force on the wire
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