Principles of Electricity: Electric Charge and Force

Electric Charge Just as in magnetism, in electricity: Protons- (+) positive electric charge Electrons (-) negative electric charge Just as in magnetism, in electricity: Charges that are the same repel each other Charges that are opposite attract

Magnetism vs. Electricity Interaction between magnetic poles A single magnetic pole CANNOT exist alone Electricity: Interaction between electric charges Electric charges CAN exist alone

Electric Force the attraction or repulsion between electric charges

Features of a circuit Have devices that run by electrical energy Source of electrical energy Connected by conducting wires

Open/Closed Circuits Open = Incomplete circuit 1. No energy can run Closed = Complete circuit 1. Energy can follow a path

Types of Circuits Series circuit  only one path for electricity to follow Parallel circuit  more than one path for electricity to follow

The symbols for the various components are as follows: Light bulbs Switch Wires Voltage Source R1 + - V V

Put it all together Now that you know what the parts are, let’s draw a series circuit and a parallel circuit.

What is current? Continuous flow of electric charges through a material (wire) Two factors that affect current: conductors and insulators

Ohm’s Law Ohm’s Law states that there is a relationship between current, voltage, and resistance V = IR Voltage = Current x Resistance

Conductors Materials that transfer electric charge well What kinds of materials do you think would make good conductors?

Conductors Metals

Insulators Materials that transfer electric charges poorly What kinds of materials do you think would make good insulators?

Insulators Nonmetals