Electrical Units and Laws

• Voltage is measured in Volts (V) and indicates potential difference or pressure.
• Current is measured in Amps (A) and indicates the flow of electric charge.
• Resistance is measured in Ohms (Ω) and indicates how well electrons pass through a material.
• Wattage is measured in Watts (W) and indicates power.
• Charge is measured in Coulombs (C).

Ohm's Law (Resistance)

• V = IR
• Voltage equals Current multiplied by Resistance.
• Example: A series circuit with a 12V battery connected to a 6Ω resistor has a 2A current.

Watt's Law (Power)

• W = IV
• Wattage equals Current multiplied by Voltage.
• Australian power supply is typically 230V AC at 50Hz.

Coulomb's Law (Charge)

• C = It
• Coulombs equal Amperage multiplied by time (in seconds).

Faraday's Law of Induction (Induced Voltage)

• V = -N(dΦ/dt)
• Induced voltage equals the negative number of loops multiplied by the change in magnetic flux over the change in time.

Currents

• Static electricity involves the movement of electrons between surfaces, causing temporary shocks.
• Example: Combing hair causes the comb to brush off electrons, making the hair positively charged.
• Sunlight can ionize metal lattices, creating free electrons.
• Current electricity involves the movement of electrons through a circuit.

Current Types

• In a series circuit, the current is constant, and voltage is shared across components.
• In a parallel circuit, the voltage is constant, and current is shared across loops.
• Electricity follows the path of least resistance.
• In a parallel circuit, if one path has half the resistance of another, it receives double the current because voltage is consistent.

Electromagnetism

• Electricity generation involves using water, steam, or another medium to turn a turbine/rotor, which rotates a magnet.
• The rapid rotation of the magnet creates a changing magnetic field, inducing AC current.
• This process creates a potential difference, causing electricity to flow.

Electrical Components

• Cell: Generates electrical current with a cathode and anode.
• Batteries: Utilize materials with potential electrical energy, such as lithium-ions
• Switches: Control the flow of electrical current.
  • An open switch creates an open circuit, stopping current flow.
  • A closed switch creates a closed circuit, allowing current flow.
• Diode: Conducts electricity in one direction with low resistance on one end and high resistance on the other.
  • Cathodes are positive, where reduction (gain of electrons) occurs.
  • Anodes are negative, where oxidation (removal of electrons) occurs.
• Globe: Emits light.
• Resistors: Reduce electric current.
• Capacitors: Store electricity in the form of charge.
• Fuse: Provides overcurrent protection.