Unit 7

Magnetism

Magnetic forces are due to movement of charged particles and all magnets have a north and south pole.

Like charges,  magnetic poles can attract or repel without touching. Opposite poles attract and like poles repel. The space around a magnetic contains a magnetic field.

• Magnetic fields, as seen above travels from north to south. 
• Magnetic domains are a cluster of atoms rotating "out of control" 
• Magnets work when these domains begin to align and rotate all in the same direction. 

Generators/ Transformers

A generator is a way to induce voltage by moving a coil. This is possible by rotating the cop in a stationary magnetic field. Generator take in mechanical energy and out put electric energy

• Transformers are machines that transfer energy from a primary to a secondary circuit.
• Transformers are used to keep current low, which produces less heat which in turn saves energy. It steps up or down voltage without changing energy.
• Primary is the input and secondary is the output. Now if the primary and secondary have the same amount of turns the input and output alternating voltages will be equal. BUT if the secondary coil has more turns then the primary then alternation voltage in the secondary is greater than the primary thus the voltage must be "stepped up" and if the primary is greater than the secondary the voltage must be "stepped down".
• The relationship between the primary and secondary voltages in relation to the number of turns is show by the following equation:

The rate in which energy is transferred is called POWER

• (Voltage X Current)primary = (Voltage X Current)secondary