Magnetism and Electromagnetism

Question 1

Two magnets are brought very close together but do not touch. Do they exert a force on each other?

Answer 1

yes

Question 2

The two poles on a bar magnet are called the north and the __________ pole.

Answer 2

south

Question 3

Which of these materials is magnetic?

Answer 3

cobalt

Question 4

Which type of magnet would you use to hold up a picture on a fridge door?

Answer 4

permanent magnet

Question 5

In a magnet, the magnetic field is strongest at the points called the __________.

Answer 5

poles

Question 6

In a bar magnet we can say that unlike poles do what?

Answer 6

attract

Question 7

Iron usually forms only an __________ magnet that loses its magnetism when moved away from a magnetic source.

Answer 7

induced

Question 8

The needle of a compass points towards the Earth’s… what?

Answer 8

geographic north pole

Question 9

A magnet that keeps its magnetism after being moved away from a magnet is referred to as which type of magnet?

Answer 9

permanent magnet

Question 10

In a bar magnet we say that like poles do what?

Answer 10

repel

Question 11

When a piece of iron is placed next to a magnet it also becomes magnetised. This type of magnetism is called __________ magnetism.

Answer 11

induced

Question 12

The magnetic field around a bar magnet is strongest at its poles. We can see this on the diagram below, where the magnetic field lines are more __________ at the ends of the magnet.

Answer 12

concentrated

Question 13

The region around a magnet where a force acts on another magnet is called the magnetic __________.

Answer 13

field

Question 14

If two bar magnets are brought together will the north pole of the first magnet attract or repel the south pole of the second magnet?

Answer 14

attract

Question 15

If two bar magnets are brought together will the south pole of the first magnet attract or repel the south pole of the second magnet?

Answer 15

repel

Question 16

When we show the direction of a magnetic field at a certain point, we are showing the direction of the force that would act on a __________ pole placed at that point.

Answer 16

north

Question 17

What is the direction of the magnetic field line in a magnet?

Answer 17

north pole to south pole

Question 18

A magnet has a magnetic __________ around it.

Answer 18

field

Question 19

What type of force exists between a magnet and a magnetic material?

Answer 19

attraction

Question 20

Induced magnetism always causes a force of ___________.

Answer 20

attraction

Question 21

A magnet’s __________ are where its magnetic forces are the strongest.

Answer 21

poles

Question 22

Steel usually forms a __________ magnet that keeps its magnetism when moved away from a magnetic source.

Answer 22

permanent

Question 23

Which of these is a reason electromagnets are sometimes more useful than permanent magnets?

Answer 23

electromagnets can be switched off and on

Question 24

What shape will the magnetic field around a straight wire carrying an electric current be?

Answer 24

circular

Question 25

True or false? Electric currents always produce magnetic fields.

Answer 25

true

Question 26

True or false? Electromagnets are a type of permanent magnet.

Answer 26

false

Question 27

True or false? A cable that connects an electrical appliance to the mains will have a magnetic field around it when the appliance is being used.

Answer 27

true

Question 28

An electromagnet is a __________ with an iron core.

Answer 28

solenoid

Question 29

An advantage of electromagnets over bar magnets is that you can easily vary the __________ of the magnetic field.

Answer 29

strength

Question 30

True or false? The magnetic field around a solenoid is the same shape as the magnetic field around a bar magnet.

Answer 30

true

Question 31

A __________ is a long coil of wire.

Answer 31

solenoid

Question 32

A solenoid is a…

Answer 32

long coil of wire

Question 33

The _________ of the magnetic field depends on the direction of the current.

Answer 33

direction

Question 34

The direction of the ____________ _______ depends on the direction of the current.

Answer 34

magnetic field

Question 35

The direction of the magnetic field depends on the ___________ of the current.

Answer 35

direction

Question 36

The direction of the magnetic field depends on the direction of the ________.

Answer 36

current

Question 37

The ________ of the magnetic field depends on the direction of the current.

Answer 37

direction

Question 38

The direction of the ____________ _______ depends on the direction of the current.

Answer 38

magnetic field

Question 39

The direction of the magnetic field depends on the direction of the _________.

Answer 39

current

Question 40

What name is given to a magnet produced by an electric current?

Answer 40

electromagnet

Question 41

A straight wire and a solenoid each have a current of 6 amperes running through them. Which will have a weaker magnetic field?

Answer 41

straight wire

Question 42

Wrapping a _____ into a solenoid (coil) will make the magnetic field stronger

Answer 42

wire

Question 43

Wrapping a wire into a _________ (coil) will make the magnetic field stronger

Answer 43

solenoid

Question 44

Wrapping a wire into a solenoid (coil) will make the __________ _____ stronger

Answer 44

magnetic field

Question 45

Wrapping a wire into a solenoid (coil) will make the magnetic field __________

Answer 45

stronger

Question 46

__________ a wire into a solenoid (coil) will make the magnetic field stronger

Answer 46

wrapping

Question 47

What will happen to the magnetic field strength of a solenoid if an iron core is added to it?

Answer 47

it will increase

Question 48

A wire with a current running through it can be shaped into a tightly wound coil in order to increase the magnetic field it creates. What is the name of the tightly wound coil shape?

Answer 48

solenoid

Question 49

what is a solenoid?

Answer 49

a coil of wire

Question 50

what is a coil of wire called?

Answer 50

solenoid

Question 51

True or false? Electromagnets are often used to lift iron and steel scrap in scrapyards.

Answer 51

true

Question 52

True or false? A solenoid always has a magnetic field around it, even when it is not carrying an electric current.

Answer 52

false

Question 53

Which type of magnets can be turned on and off using electricity?

Answer 53

electromagnets

Question 54

The motor effect happens because the current-carrying wire produces a __________ __________ that interacts with the field of the magnet.

Answer 54

magnetic field

Question 55

True or false? When using Fleming's left-hand rule, the thumb and fingers must be at right-angles to one another.

Answer 55

true

Question 56

What units are used for force?

Answer 56

newton

Question 57

What units are used for current?

Answer 57

ampere

Question 58

Which equation connects force, magnetic flux density, current and length together?

Answer 58

force = magnetic flux density x current x length

Question 59

______ = magnetic flux density x current x length

Answer 59

force

Question 60

force = __________ ____ _______ x current x length

Answer 60

magnetic flux density

Question 61

force = magnetic flux density x ________ x length

Answer 61

current

Question 62

force = magnetic flux density x current x ______

Answer 62

length

Question 63

When using Fleming's left-hand rule, the first finger points in the direction of the... what?

Answer 63

magnetic field

Question 64

What effect would increasing the strength of the magnetic field have on the force caused by the motor effect?

Answer 64

increase it

Question 65

True or false? When using Fleming's left-hand rule, the direction of the magnetic field is taken to be from south to north.

Answer 65

false

Question 66

Loudspeakers and headphones use the __________ effect to make pressure variations in sound waves.

Answer 66

motor effect

Question 67

Will there be a force on a current-carrying wire in a magnetic field if the current and fields are parallel?

Answer 67

no

Question 68

The ________ and the magnetic field lines need to be at right angles to produce a force.

Answer 68

current

Question 69

The current and the ________ ______ lines need to be at right angles to produce a force.

Answer 69

magnetic field

Question 70

The current and the magnetic field lines need to be at _____ ________ to produce a force.

Answer 70

right angles

Question 71

The current and the magnetic field lines need to be at right angles to produce a ______.

Answer 71

force

Question 72

If a wire carrying an electric current is placed in a magnetic field, a force is produced. What name is given to this effect?

Answer 72

motor effect

Question 73

When using Fleming's left-hand rule, the second finger points in the direction of the __________.

Answer 73

current

Question 74

Would increasing the strength of the magnetic field have an effect on the direction of the force caused by the motor effect?

Answer 74

no

Question 75

A wire carries a current of 2A through a magnetic field. The wire experiences a force. What will happen to the size of this force if the current is reversed?

Answer 75

stays the same

Question 76

When using Fleming's left-hand rule, the thumb points in the direction of the... what?

Answer 76

force

Question 77

Loudspeakers receive energy through __________ and transfer it into the surroundings in sound.

Answer 77

electricity

Question 78

What units are used for magnetic flux density?

Answer 78

tesla

Question 79

__________'s Left Hand Rule is used to predict the direction of the force on a current-carrying wire.

Answer 79

Fleming

Question 80

Louis is studying a current-carrying wire in a magnetic field. Name the rule that he can use to work out the direction of the force from the direction of the current and the magnetic field.

Answer 80

Fleming’s left hand rule

Question 81

Will there be a force on a current-carrying wire in a magnetic field if the current and fields are at right-angles to one another?

Answer 81

yes

Question 82

A wire carries a current through a magnetic field. A force on the wire makes it move left. In which direction would the wire move if the direction of the magnetic field was reversed?

Answer 82

right

Question 83

Name an example of an everyday application that does NOT contain a motor?

Answer 83

kettle

Question 84

The diagram shows a wire carrying an electric current. This wire is made from copper, which is not a magnetic material. Will the wire still move?

Answer 84

yes

Question 85

A wire carries a current of 2A through a magnetic field. The wire experiences a force. What will happen to the size of this force if the current is changed to 1A?

Answer 85

decrease

Question 86

True or false? A current-carrying straight wire placed in a magnetic field can move because it experiences a force.

Answer 86

true

Question 87

Loudspeakers and headphones convert changes in the __________ of electrical circuits into pressure variations in sound waves.

Answer 87

current

Question 88

Which hand would you use to work out the direction of the force from the direction of the current and magnetic field for a current-carrying wire in a magnetic field?

Answer 88

left

Question 89

A wire is carrying an electric current through a magnetic field. A force on the wire makes it move to the right. In which direction would the wire move if the current in the wire changed direction?

Answer 89

left