The current generated in a circuit moving relative to a magnetic field.

The effect of inducing a current by the relative movement of a circuit and a magnetic field.

A sensitive ammeter able to measure thousandths of an amp.

The potential difference generated in a conductor moving relative to a magnetic field.

The generator effect

Physics

Plotting magnetic fields

An electromagnet

Strength of an electromagnet

Applications of electromagnets

The motor effect

An electric motor

Electric generators

Applications of motor and generator effects

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

This unit explores magnetism, including permanent and induced magnets, magnetic fields, and Earth's magnetism. It covers current-induced magnetic effects, electric motors, and devices like microphones and loudspeakers, with an emphasis on models, calculations, and practical applications.

Electromagnetism

Which of the following is used to measure very small currents?

A current appears when a circuit and magnetic field move relative to each other.

A magnetic field appears when a current and circuit move relative to each other.

A circuit appears when a magnetic field and current move relative to each other.

Which of the following describes the generator effect?

The diagram shows a piece of wire in a magnetic field, represented by field lines. In which directions can the wire be moved to make a current appear in the wire?

When current appears in a wire because the wire is moved through a magnetic field; this is called {{}} current.

Leave the magnet in the middle of the coil.

Hold the magnet still and move the coil so that the magnet goes inside it.

With the magnet in the coil, move both at the same speed in the same direction.

A pupil has a coil which is part of a complete circuit, and also a magnet. Which of the following are ways of making a current appear in the coil?

There is an induced potential across the coil.

Moving the magnet out of the coil changes the current direction.

While the magnet moves into the coil, there is a force pushing it sideways.

If the magnet moves twice as fast, the current doubles.

If the number of turns of the coil is doubled, the current halves.

A magnet is moved into a stationary coil, causing a current in the coil. Which of the following statements are correct?

The time taken for a unit of charge to flow past a point.

The amount of charge flowing past a point every second.

Which of the following is a definition of current?

Which of the following is used to measure current?

Which of the following is used to measure potential difference?

There is an electric field between the ends of the wire.

A voltmeter connected across the ends of the wire would show a non–zero reading.

There is a potential difference between two ends of a wire. Which of the following statements are correct?

A force acts on a current–carrying wire in a magnetic field.

A force acts on a current–carrying wire in an electric field.

A current–carrying wire exerts a force on a magnetic field.

A current-carrying wire exerts a force on an electric field.

Which of the following describes the motor effect?

A cell has one positive end and one negative end.

A cell has no potential difference between its ends.

Which of the following statements about cells are correct?

The generator effect

Lesson outcome