Magnetism and Electromagnetism Flashcards

Flashcards covering key concepts from lectures on magnetism and electromagnetism.

Which elements are commonly found in magnetic substances?

Iron (Fe), Nickel (Ni), and Cobalt (Co)

What type of force is a magnetic force?

A non-contact force

Outside of a magnet, what direction do magnetic field lines travel?

From North to South

Inside of a magnet, what direction do magnetic field lines travel?

From South to North

Why are magnetic domains always present in ferromagnetic materials?

Due to the way the atoms bond to form the material.

In an unmagnetized condition, how will a ferromagnetic material react to a magnet?

It will be attracted to the magnet but will not act as a magnet itself.

What happens to magnetic domains when a ferromagnetic material is magnetized?

The magnetic domains align parallel to each other.

How do temporary magnets differ from permanent magnets?

Temporary magnets only maintain their magnetism while current is flowing through them.

What happens to wires in a circular conductor with a stronger field in the middle?

The wires are pushed apart.

What happens to wires in a circular conductor with a weaker field in the middle?

The wires are pulled together.

How do you determine the North Pole of a solenoid using your right hand?

The thumb points towards the North Pole.

Name three uses of electromagnets.

Doorbells, tellephones, and heavy metal scraps.

List three factors that affect the strength of a magnetic field.

Number of windings, current strength, and type of metal core.

What is the symbol and unit for magnetic flux?

Symbol: Φ (Phi), Unit: Wb (Weber)

Name three ways to increase magnetic flux.

Larger surface area, stronger magnetic field strength, and optimal angle between field lines and surface.

What is the unit for magnetic flux density (field strength)?

Tesla (T)

According to Faraday's Law, what happens when a conductor and a magnetic field move relative to each other?

An EMF is induced across the ends of the conductor.

What is induced in AC generators?

Alternating current

Which hand rule applies to DC motors?

Flemming's left hand rule

What is another name for induced force?

Lorentz force

How does a DC motor work?

Force is produced by the interaction between the magnetic field of the current-carrying conductor and the external magnets.

What is the purpose of a splitting commutator in a DC motor?

To change the direction of the current ensuring rotation in one direction.