Electricity (Lesson 2)

An atmospheric discharge of electricity Lightning

-- Lightning +

Applications of Grounding Grounding strips on cars/trucks Grounding wires on workers who make computers, electronics Applications of Grounding

Difference between static and current? Electricity

Electric current: the controlled movement or flow of electric charge (electrons) Current Electricity

We know that electrons can move. How can we get them to move? Current Electricity

Electrical Conductors Types of materials that are good conductors: metals salts graphite Electrical Conductors

a connection of electric components that an electric charge can flow along (a closed path) Electric Circuit

Let’s use a flashlight as an example

Parts of a circuit: Source Switch Conductor Load Electric Circuits

Circuit Example

Where electric current is generated Source

Control mechanism in circuit (ON / OFF) Switch

Item within the circuit that uses the electricity to do work Load

Material used in a circuit that allows the flow of electric current Conductor

Current Measured in the conductor of the circuit Current is the rate at which charge is flowing across a point Current is measured in units called Amperes (A) Current

The measure of an opposition to a circuit provided by a load Resistance is a material’s tendency to resist the flow of charge Resistance is measured in units called Ohms (W) Resistance

a measure of the amount of electric charge passing a point in a measure of time Ampere

Amount of charge in a circuit 1 C = 6.241 * 1018 electrons Coloumb (C)

How to calculate Current Current (A) = Charge (C) Time (s) How to calculate Current

Voltage The force moving the electrons to flow is Voltage Voltage is the difference in charge between two points Voltage is measured in a unit called Volts (V) Voltage

How to Calculate Voltage Ohm’s Law V = I x R Try Problems How to Calculate Voltage

Power is the rate, per unit time, that electrical energy is transferred in an electrical circuit Power is measured in units of Watts (W) Power

Power Equation P = V x I Try Problems How to Calculate Power

All values can be found with two others

Circuit Diagrams

Circuit Diagrams

Circuit Diagrams