INTRODUCTION TO CURRENT ELECTRICITY AND CIRCUIT DIAGRAMS SNC 1D1UNIT 3: ELECTRICITY: sections:12.1,12.2 & 13.1

REVIEW  Static electricity is the imbalance of charges on the surface of an object  Insulators are used for static electricity, because they do not allow electrons to travel freely through the object, but remain on the surface

What is Current Electricity?  The movement or flow of electrons in a closed path (circuit)  Conductors are used for current electricity, because they allow electrons to travel freely through an object Conductor

Electrical Circuits  The pathway in which electrons flow  As soon as an electric device is turned on, the circuit is closed and electrons begin to flow through it

Parts of a Circuit ComponentDefinitionExample Energy source Provides electrical energy in a circuit. Electrons flow from the negative terminal to the positive terminal. Cells, batteries, outlets, generators Electrical Load converts electrical energy into another form of energy Light Bulb  Light Energy Motor  Kinetic Energy Control Device Used to open (turn off) or close (turn on) a circuit safely and control the movement of electrons Switch, fuse Conductors Metals that connect all loads and the battery in a closed path for electrons to flow. Conducting wires

Circuits and Circuit Diagrams  Circuit diagrams: a way of drawing an electric circuit using symbols to describe each part of a circuit

Circuit Diagram Symbols Conducting WireOne Dry Cell2-Cell Battery 3-Cell BatteryLight BulbOpen Switch Closed SwitchMotorFuse ResistorAmmeterVoltmeter M A V

Series Circuit  A series circuit is a circuit in which electrons flow in only one path (a continuous loop) and pass through all components of the circuit.  In a series circuit, the voltage decreases as you increase the number of loads.  Ex : A series circuit with a battery, conducting wires, two lamps and a switch

 In a series circuit, if you remove one load, the circuit becomes incomplete (open)  The charges pass through every load before returning to the electrical source to be re-energized again.

Parallel Circuits  PARALLEL CIRCUIT  A parallel circuit is a circuit in which electrons flow in multiple paths.  In a parallel circuit, the loads are on at least two different branches. The electrons that leave the source are split between the loads.  In a parallel circuit, if you remove one load, there are still other paths for electrons to flow.  In a parallel circuit, as you increase the number of loads, the current at the battery will increase to meet the demand of multiple paths of current. Overall, the current across each load is smaller than at the battery.

In a parallel circuit the loads are connected by branches so that there are two or more paths for electrons to flow. EX: A parallel circuit with a battery, conducting wires, two lamps and a switch Homework : 1)Read section 13.1 and do Q # 1-7 on pg.554 2)Read section 12.1 and 12.2 and do # 1-6 on p.510