Magnetism and Electromagnetism Lecture Notes

These flashcards cover the key concepts and definitions related to magnetism and electromagnetism based on the provided lecture notes.

What is a magnetic domain?

A microscopic region within a magnetic material where the atomic or molecular magnetic moments are aligned in the same direction.

What does 'flux density' measure?

The strength of a magnetic field in a volume of space.

What is induced magnetism?

Magnetism produced in magnetic material by a permanent magnet or electromagnet.

What is induction in magnetism?

A potential difference produced when the flux passing through a conductor changes in direction or strength.

What does the magnetic field represent?

The area around a magnet where it will produce a force on another magnet or magnetic metal.

What is the motor effect?

Force produced on a conductor carrying a current placed at right angles to a magnetic field.

What is a solenoid?

A coil of wire carrying a current that produces a magnetic field with the same shape as a bar magnet.

What unit is used to measure magnetic flux density?

Tesla.

What is the left-hand rule in electromagnetism?

A rule used to determine the direction of the force on a current-carrying conductor in a magnetic field.

What happens when a wire carrying a current is placed in a magnetic field?

It will experience a force if it is perpendicular to the magnetic field.

What does increasing the strength of the magnetic field or the size of the current do?

It increases the size of the force on the conductor.

What is the generator effect?

The process of using movement to produce a current in a wire by placing a conductor in a magnetic field and moving it.

How can one increase the induced potential in electromagnetic induction?

By increasing the strength of the magnetic field, the number of turns on the solenoid, or the speed of movement/changes to the magnetic field.

What is the role of a commutator in a motor?

It allows the coil to spin without the wires getting tangled up.

What do loudspeakers and microphones utilize in their operation?

The motor effect, using a moving coil in a magnetic field to create sound waves or convert sound waves into electrical signals.

What is a step-up transformer?

A transformer with more coils on the secondary than the primary, increasing the potential difference.

What are the four primary magnetic materials?

Iron, steel, cobalt, and nickel.

What is the right-hand grip rule used for?

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

What is the formula for calculating the force on a wire in a magnetic field?

F = B \times I \times l, where F is force (Newtons), B is magnetic flux density (Tesla), I is current (Amperes), and l is length (meters).

What is a step-down transformer?

A transformer that has fewer turns on the secondary coil than the primary coil, resulting in a lower output potential difference.

Why is the core of a transformer made from iron?

Iron is a soft magnetic material that can be easily magnetized and demagnetized, which efficiently transfers the magnetic field between coils.

In which direction do magnetic field lines always point?

From the North pole of a magnet towards the South pole.

How do step-up transformers improve efficiency in the National Grid?

By increasing potential difference, they allow the same power to be transmitted at a lower current, reducing energy lost as heat.

What component is added to a solenoid to turn it into an electromagnet?

A soft iron core.