GPS S8P5. Students will recognize characteristics of gravity, electricity, and magnetism as major kinds of forces acting in nature. Demonstrate the advantages and disadvantages of series and parallel circuits and how they transfer energy.

How are electric circuits wired? What exactly is electricity? What are the advantages and disadvantages of series and parallel circuits? How do they transfer energy? EQs

Electricity is the movement of electrons Atoms contain charged particles known as protons (+) and electrons (-) Like charges repel Unlike charges attract Electrons move from an area that is negatively charged (extra electrons) to an area that is positively charged (wanting electrons).

Like charges repel. Unlike charges attract

Electricity 1. Static Is stationary E.g. Brush your hair Wool socks in tumble dryer 2. Current Flows around circuit E.g. turn on light Walkman Electricity occurs in 2 different forms

Static Electricity Occurs with materials which are insulators Rubbing adds or removes electrons Object becomes charged Like objects repel, unlike attract

Current Electricity Electrons flow through a conductor Negative to positive Circuit = continuous loop for electrons to flow Needs energy supply Energy user

Has a single loop for electrons to travel round Components are connected one after another Current has to travel through all components Current is the same at all points Voltage is shared between components Series circuit

Uses for Series Circuits Series circuits are useful in wiring burglar alarms. If any part of the circuit fails, there will be no current in the system and the alarm will sound

Has two or more paths for electrons to flow down Current is shared between the branches Sum of the current in each branch = total current Voltage loss is the same across all components Parallel circuit

Uses for Parallel Circuits Almost all appliances are built with parallel circuits so that they will keep working if part of the system fails.

Electricity is forced around a circuit by an electrical force field Flow of electricity around a circuit is called CURRENT (I) Current measured in amps (A) Voltage (V) – Increase or decrease in the amount of electrical energy carried by the current. Electricity

Current is the flow of electrons around a circuit Measured in amperes (amps) DC = direct current like battery Electrons flow in one direction AC = Alternating current like mains Electron flow changes direction 50x per second Current (I)

Measures CURRENT (I) Unit = Amp (A) Current is flow of electrons Connect in series at the point you wish to measure RED to RED and BLACK to BLACK Ammeter

Gain or loss of energy as it passes through a component Voltage lost = voltage gained In series voltage loss is shared between components In parallel voltage loss is the same across all components Voltage (V)

Measures voltage Unit = Volt (V) Voltage increases as it passes through energy suppliers Voltage is decreased as it passes through users Connect in parallel around a component Voltmeter

SUMMARY In SeriesIn Parallel Current Voltage Always the same The branches share electrons and add to the total Voltage from source = voltage used Voltage is shared between power users Voltage is the same in all branches

R The amount that a component slows the current or the opposition to the flow of electric charge. Resistance is measured in ohms. resistance

The creation of a harmless, low- resistance path—a ground—for electricity to follow. Grounding is an important electrical safety procedure. grounding

Electric Discharge The loss of static electricity as charges move off an object is called electric discharge. One of the most dramatic examples of electric discharge is lightning. The next slide shows how lightning is formed. Static Electricity

AC and DC There are two kinds of electric current—direct current (DC) and alternating current (AC).

Forming a Loop An electric circuit is a complete, closed path through which electric charges flow. All circuits need three basic parts: an energy source, wires, and a load. Parts of an Electric Circuit

A Switch to Control a Circuit Sometimes, a circuit also contains a switch. A switch is used to open and close a circuit.

Circuit Failure Broken wires or water can cause a short circuit. In a short circuit, charges do not go through one or more loads in the circuit. Fuses A fuse has a thin strip of metal. Fuses keep charges from flowing if the current is too high.

Circuit Breakers A circuit breaker is a switch that automatically opens if the current is too high. Charges stop flowing. Electrical Safety Tips Do not overload circuits by plugging in too many electrical devices. Do not use electrical devices near water.