1. ELECTRICITY The Shocking truth!!!

2. WHAT IS ELECTRICITY? Electricity is a type of energy caused by small, negatively charged particles called ELECTRONS. There are 2 types: STATIC electricity – the charges build up on something but don’t go anywhere. CURRENT electricity – charges flow through a material. In solids, these charges are electrons. In liquids, they are IONS (see Electrolysis in Chemistry).

3. HOW DOES A CURRENT FLOW? The accepted convention is that we always show an electric current flowing from + to -. In fact, it is negative electrons flowing, so it really goes from – to +. WRONG!!!

4. WHAT IS CURRENT? The CURRENT (I) is the amount of charge (Q) flowing per second. It is measured in AMPS (A). HEAT is produced due to resistance. MAGNETIC FIELDS can be produced around the wire. When a current flows in a wire it can have 2 effects: I = Q / t Q = charge in Coulombs (C) t = time in seconds (s)

5. CURRENT IN CIRCUITS The CURRENT is measured using an AMMETER, connected in series. In SERIES circuits, all devices get the same current. In PARALLEL, the current splits up and each device gets a share. The bigger the resistance, the less current in each device.

6. WHAT IS VOLTAGE? The VOLTAGE (V) is the amount of energy (W) given per Coulomb of charge (Q). It is measured in VOLTS (V). We also call it POTENTIAL DIFFERENCE. A larger voltage causes more charges to flow, so the current will increase. The more resistance a material has, the more voltage we need to push a current through it. V = W / Q W = energy in joules (j) Q = charge in Coulombs (C)

7. VOLTAGE IN CIRCUITS The VOLTAGE is measured using a VOLTMETER, connected in parallel, across a device. In SERIES circuits, all devices get a share of the voltage – it splits up. In PARALLEL circuits, all devices get the full voltage – it does NOT split up.

8. WHAT IS RESISTANCE? The RESISTANCE (R) is the opposition a material puts up to the flow of charge. It is measured in OHMS (  ). All metals are good conductors so they have a low resistance. We call this formula Ohm’s Law. The more resistance a material has the lower the current through it. R = V / I V = Voltage in Volts (V) I = Current in Amps (A)

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