Introduction to Current Electricity and Circuits

Learning Goals

By the end of this class I should be able to…

• …identify basic components of a circuit diagram

• …explain proper safety procedures regarding the use of electricity

Introduction to Current Electricity

Current Electricity• A steady flow of electric charges that

move through a conductor in a controlled way.

Current Electricity vs. Electrostatic Discharge

Current Electricity vs. Electrostatic Discharge

• Similarities– Both involve the movement of electrons

• Differences– Electrostatic Discharge follows an

unpredictable path and occurs very quickly

– Current follows a controlled path to power a device and is a steady flow of electrons.

What causes electrons to flow?• Electric Cells

– A portable device that converts chemical energy to electrical energy

– Consist of two electrodes and a conducting solution called an electrolyte

What causes electrons to flow?• Fuel Cell

– Uses a continuous supply of chemicals to operate.

– Hydrogen fuel cell.

What causes electrons to flow?• Solar Cell

– Uses energy from the Sun to create electric energy

Parts of a Circuit

1. Electrical Source– The source of the electrical energy in a

circuit– Common Examples:

• Battery

• Outlet

Introduction to Current Electricity

2. Conductors– The part of the circuit that creates the

path for the electricity to flow.

Introduction to Current Electricity

3. Control or Switch– A device in a circuit that controls the flow

of electrons by opening or closing the circuit.

Circuit symbol

Introduction to Current Electricity

4. Load– The part of the circuit that converts

electrical energy into other forms of energy.

Grade 9 Circuit Symbols

Introduction to Current Electricity

Current Electricity• A steady flow of electric charges that

move through a conductor in a controlled way.

Electrical Safety

1. Always ensure that your hands are dry and that you are standing on a dry surface

2. Do not use faulty equipment– Corroded batteries– Frayed wires

3. Only operate a circuit after it has been approved by your teacher.

– Incorrect connections could cause short circuits or explosions.

4. Always open the circuit before making any changes.