Magnetism and the Motor Effect (EdExcel)

What are the main magnetic materials that magnets attract?

Iron, Steel (an alloy of iron), Nickel, Cobalt.

Which materials are not attracted to magnets?

Non-magnetic materials like wood, plastic, aluminium, and copper.

What are the two poles of a magnet?

North-seeking pole (N) and South-seeking pole (S).

What fundamental rule of magnetism describes the behavior of like and unlike poles?

Like poles repel, and unlike poles attract.

How do magnetic forces operate in terms of contact?

Magnetic forces are non-contact forces, meaning they can act at a distance.

What are permanent magnets?

Magnets that produce their own persistent magnetic field and retain their magnetism over time.

What happens to induced magnets when they are removed from a magnetic field?

They lose most or all of their magnetism.

How are magnetic fields represented visually?

Using magnetic field lines (lines of force).

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

Field lines emerge from the North pole and enter the South pole.

What does the density of magnetic field lines indicate?

The closer the field lines are together, the stronger the magnetic field is in that region.

What happens to magnetic field lines when two like poles are close together?

Field lines are repelled from each other, showing a weaker field between the poles.

What does a solenoid create when an electric current flows through it?

A stronger, more uniform magnetic field inside the solenoid.

What is the role of the Right-Hand Grip Rule in electromagnetism?

It helps determine the direction of the magnetic field around a current-carrying wire.

What is an electromagnet?

An electromagnet is created when a solenoid is wrapped around a ferromagnetic core, typically soft iron.

What can increase the strength of an electromagnet?

Increasing the current, increasing the number of turns in the solenoid, or using a more magnetically permeable core material.

What is the Motor Effect?

When a current-carrying conductor placed in a magnetic field experiences a force.

How does Fleming's Left-Hand Rule help in electromagnetism?

It helps determine the direction of the force on a current-carrying conductor in a magnetic field.

What equation describes the force on a current-carrying conductor in a magnetic field?

F = B × I × l, where F is force, B is magnetic flux density, I is current, and l is the length of the conductor.

What happens to the force on a wire if it is parallel to the magnetic field lines?

If the wire is parallel to the magnetic field lines, it experiences no force.

What are the basic components of a DC electric motor?

Rotor (Armature), Magnets, Commutator, Brushes.

What ensures continuous rotation in a DC motor?

The commutator reverses the direction of the current, ensuring the turning effect continues in the same direction.

What is the purpose of a relay?

To use a small current in one circuit to control a larger current in another circuit.

How do loudspeakers work using electromagnetism?

An electromagnet interacts with a permanent magnet's field, causing movement that creates sound waves.

Name an application of electromagnets.

Electric bells, scrap metal cranes, and relays are applications of electromagnets.

What happens to induced magnets in the presence of a permanent magnet?

Induced magnets always experience an attractive force towards a permanent magnet.

What measures the strength of the force on a conductor in a magnetic field?

It can be increased by increasing the magnetic flux density, increasing the current, or increasing the length of the conductor.