is an insulated wire wound into the shape of a spring.

is very pure iron that cannot be made into a permanent magnet.

describes the relationship between two variables, in which doubling the value of one variable doubles the value of the other.

show the accuracy of each measurement on a graph.

An electromagnet

Physics

In the Magnets and electromagnets unit, pupils learnt about rules for magnets, magnetic fields of bar magnets, and the properties and uses of electromagnets. 

Electromagnetism

There is a magnetic field around the wire.

Which of the following explains why a compass is affected by a current–carrying wire made of copper?

It is easy to mould into the right shape.

It strengthens the field of the electromagnet.

Which of the following are reasons why soft iron is used for the core of an electromagnet?

A pupil investigates the relationship between the current in an electromagnet’s coil and the number of pins the electromagnet can pick up. Which of the following are control variables?

Larger numbers are easier to show on a graph than smaller numbers.

They are less likely to become permanently magnetised by the electromagnets.

Smaller differences between the strengths of the electromagnets can be measured.

A pupil compares the strengths of different electromagnets by counting how many paper clips each can pick up. Which of the following explains why small paper clips are more suitable than large ones?

a straight line that passes through (0, 0)

a straight line that does not pass through (0, 0)

Two variables, $$p$$ and $$q$$, are related but are not directly proportional to each other. Which of the following are possible graphs of $$p$$ against $$q$$?

markings that are made on the anomalous points on a graph

lines that show the relationship between the variables on a graph

lines that show the range of possible values of a point on a graph

rails put around experimental apparatus so that it does not fall off the table

Which of the following describes what error bars are?

Which of the following instruments can show whether you are facing north?

All metal elements are magnetic materials.

Most metal elements are not magnetic materials.

All alloys (mixtures of metals) are magnetic materials.

Some alloys (mixtures of metals) are magnetic materials.

Some non–metal elements are magnetic materials.

Which of the following statements are correct?

the north–seeking pole of another magnet

the south–seeking pole of another magnet

Which of the following would be attracted to the north–seeking pole of a magnet?

Earth has a north–seeking pole near its geographic North Pole (in the Arctic).

Earth has a south–seeking pole near its geographic North Pole (in the Arctic).

The north–seeking pole of a magnet is attracted towards geographic north.

The south–seeking pole of a magnet is attracted towards geographic north.

A field line of a bar magnet can have gaps in it.

The closer together the field lines, the stronger the field.

Near the S pole of a bar magnet, the field line arrows point towards the S pole.

Which of the following statements about magnetic field lines are correct?

The direction of force on a positive charge.

The direction of force on a negative charge.

The direction of force acting on the north–seeking pole of another magnet.

The direction of force acting on the south–seeking pole of another magnet.

What do the arrows on magnetic field lines show?

This lesson will soon be taken down.

An electromagnet

Lesson outcome