FIK2, FIR1 & FIR2

FIK2- What is an electromagnet?

• Electromagnets are magnets that have their magnetic field produced by electric current.• The magnetic field disappears when the electric current is turned off

and reappears when the electric current is turned on.

FIK2- How are electromagnets made?• Electromagnets are made when a large number of coils of wire are

wrapped around a piece of iron.• The more coils or the higher the current of the electricity flowing

through the wires the stronger the electromagnet will be.• A simple electromagnet:

FIK2- Uses of electromagnets

• Electromagnets are common in electrical devices, motors, generators, speakers, computer hard disks, MRI machines, and scientific equipment.

FIK2- Electric motors

• Electric motors are used in many devices.• The idea behind electric motors are simple: Place an electromagnet

in the middle of a permanent magnet. When the electromagnet is turned on the magnetic fields interact and the electromagnet begins to spin.

FIR1- Electricity and Magnetism

• Electricity has negatively charged particles and positively charged particles. Magnetism only has negative charged fields but they are ordered and travel in different directions depending on the pole.• Both electricity (electric force) and magnetism can be attractive or

repulsive.• With both types of forces like charges/poles are repulsive and opposite

charges/poles are attractive.• Draw the diagram 1.• Electricity is measured in different units for different things, but our main

concern is current. Current is the flow of electric charge, so the more current the more charge moving through the wires.

• Magnetisms magnitude or strength is most easily seen by looking at the magnetic field lines.• The closer the field lines are together the stronger magnetic force.

FIR2- How do electric and magnetic forces interact?• Electric forces interact because of their charge. Two of the same

charges will repel, two different charges will attract.• This happens because all things in nature want to be electrical

neutral. If two of the same charges were together that would make the object even farther from neutral, so they repel each other.• If two different charges come together they attract and cancel the

charges out to become neutral.• The stronger the magnitude of the charges the stronger these

reactions are.• Draw diagram 2.

• Magnetic forces interact based on their poles. Since all magnets have a force field that is created by moving electrons, magnetic interaction depends on which direction the electrons are moving.• All north poles have electrons moving out and away from them.• All south poles have electrons moving in and towards them.• So two north poles together would be throwing electrons at each

other and force the two poles away. Two south poles react similarly.• A north pole and a south pole together would be a north pole

throwing electrons into a south pole directly so they would attract and move together.