Electromagnetism

Magnetism

• Magnetism - invisible lines of force
• In magnets the lines always travel from North to South
• HOWEVER
• In the Earth the lines travel from South to North
• The magnetic materials are
• Iron
• Nickel
• Cobalt
• 
• Caption: Force in a magnet

Slide 2

• 
• Caption: A basic electromagnet
• You can increase the strength of electromagnets by
• increasing the current
• increasing the number of windings

Slide 3

• Electromagnet -What is it ? For Kids (Embed)
• Caption: Source: Youtube, makemegenius

Slide 4

• DC Motor, How it works? (Embed)
• Caption: Source: Youtube, Learn Engineering

Slide 5

• Electricity - the flow of electrons along a conductor
• Voltage - measure of "electrical energy" (measured in volts)
• Voltage doesn't define the amount of energy!
• Current - the rate of flow of electrons (measured in ampere/amps)
• Resistance - measure of how much the flow is prevented (measured in Ohm)
• The Ohm's law:
• V = IR
• Therefore:
• I = V/R
• R = V/I
• V: Voltage
• I: Current
• R: Resistance

Slide 6

• 
• Caption: Source: BBC Science KS3