Current Electricity

• An electrical current is a flow of charged particles (electrons or ions) through a circuit

• In a circuit with a battery or chemical cell, electrons flow from a negative terminal to a positive terminal through the circuit

• Conductors are materials through which a current can flow

• Metals are good conductors

• Other materials like carbon or water are also good conductors

• Schematic diagrams are diagrams of electric circuits

• Symbols are used to represent different parts of an electrical circuit

Schematic Diagram

Series and Parallel Circuits

• Series circuits have a single pathway for the current

• Parallel circuits have more than one pathway for the current

• Meters are used to measure current, voltage or resistance in a circuit

Current

• a measure of the number of charged particles passing a point in a given time

• measured in amperes (A) or amps

• 1A = 1 coulomb of charge per second

• Symbol for current is I

• An ammeter is used to measure current in a circuit

• Ammeters are connected in series

Conventional Current

• In an electric circuit, electrons actually flow from the negative terminal to the positive terminal

• In conventional current, we assume they are flowing from positive to negative

Voltage

• a measure of the amount of electrical energy carried by each charged particle in a circuit

• measured in Volts (V)

• A voltmeter is used to measure voltage

• A voltmeter is connected in parallel

Resistance

• A resistor resists the flow of current in a circuit

• Resistors convert electrical energy into other forms such as heat or light

• Resistance (R) is measured in Ohms (Ω)