Electricity Foundations of Physics

Electricity The movement of charge from one place to another Requires energy to move the charge Also requires conductors to allow the charge to pass

Electric Potential Energy Energy associated with interacting charges In a continuous conduction loop, electric potential energy moves the charge through the wires

Electric Circuit Various electrical devices connected together to form a continuous conducting path. Most circuits contain a source of electric potential energy (Battery, Generator, etc.), conductors to move the charge, and a load (light bulb, electric motor, etc).

Batteries Batteries convert chemical potential energy (stored in the chemicals inside the battery) into electric potential energy

Capacitor Two layers of conducting materials separated by a layer of insulator Stores charge and electric potential energy The conducting layers are called plates A metal post called terminals are connected to each plate and extends outside the capacitor so it can be connected in a circuit.

Charging a Capacitor Connecting a capacitor into a circuit with a source of electric potential energy Electric potential energy and electric charge are stored in the capacitor.

Discharging a Capacitor Connecting a charged capacitor to a circuit without another source of electric potential energy. Electric potential energy and electric charge stored in the capacitor is transferred to load in circuit.

Electric Current (I) Describes how fast the electric charge moves through the circuit. Electric flow rate. Measured in units called Amperes or Amps for short. Current depends on both the source of electric potential energy and the load in the circuit.

Electric Potential Difference (V) The difference in electric potential energy from final and initial locations when a load is part of the circuit. Also called Voltage Measured in Volts

Resistance (R) Measures the amount of resistance to charge flow through a material. Measured in Ohms Resistance varies depending on the load and how they are connected in the circuit.

Ohm’s Law States the voltage of a circuit is the product of the circuit’s current and resistance.

Series Circuits Circuit with only one continuous conducting path The total voltage at the battery is equal to the voltages at each bulb added together. Current is constant Resistance is more when loads are connected in series.

Parallel Circuits Circuit with more than one continuous conducting path The voltage is constant The total current at battery is equal to the current at each branch of the circuit added together. Resistance is less when loads are connected in parallel