Electric Current: Basics

Current Electricity

• Current electricity is like current in a river.

• A high or fast river current means the water is rushing past the shore quickly.

• A high current in electricity means that the electrons are moving past points in the circuit quickly.

Current Electricity

• Electrons keep moving around the circuit with a constant source of energy (ex. Battery, power outlet, etc.)– Energy gives the

electrons a ‘push’

Current Electricity

• Current: the rate of electron flow past a given point in a circuit

Current Electricity

• Symbol: I• Units: Amperes (A)• Measured with: Ammeter

Potential Difference

Potential Difference

• Potential Difference/Voltage: the difference in electrical energy per unit charge measured at two different points

• Symbol: V• Units: Volts• Measured with: Voltmeter

What is an Electric Circuit?

• An electric circuit is a continuous path through which an electric current is passed

• Electric circuits convert electrical energy into other forms of energy we need – such as heat or light.

Parts of an Electric Circuit

• There are five basic parts found in a simple electric circuit.

Parts of an Electric Circuit• Energy Source– Provides electrical energy – E.g. battery, electrical outlet

Battery(energy source)

Parts of an Electric Circuit• Load– Converts electrical energy into another

form– E.g. light bulb, motor

Light Bulb (load)

Parts of an Electric Circuit• Switch– Opens or closes a circuit

Switch

Parts of an Electric Circuit• Connectors– Conducting wires carry the electrical

energyConnectors

Parts of an Electric Circuit• Meters–Measure current (ammeter) and

potential difference (voltmeter)VoltmeterAmmeter

Electrical Symbols Energy Source

One Battery(One Dry Cell)

Two Batteries (Two Dry Cells)

Electrical Symbols - Load

Light Bulb Motor

Electrical Symbols - Switch

Open Switch Closed Switch

Electrical Symbols - Connectors

Conducting wire

Electrical Symbols - Meters

Voltmeter Ammeter

Electrical Symbols - Resistors

Resistor

Series Circuit

• A circuit in which the flow of electrons follows only one path.

Parallel Circuit

• A circuit in which the electrons can flow in more than one path.