Electricity

1
Electricity

• Current
• Voltage
• Resistance
• Current, Voltage, Resistance characteristics
• AC DC
• Plugs
• Earth
• Fuses
• Power

2
Current

• Current is the amount of charge flowing past a
  point in a given time
• Current (A) Charge (C) / time (s)
• Current read by an ammeter
• connected in series

3
Potential Difference

• Voltage
• Potential difference is the energy given to or
  given by a charge when it passes a component.
• PD (V) Energy (J) / Charge (C)
• PD is taken by a voltmeter and is connected in
  parallel with the component.

4
Resistance

• Resistance is the volts per amp for a component.
• How many volts are needed to push a current of so
  many through a component.
• Resistance (Ohms) PD (V)/ Current (A)

5

• Circuit models
• Circuit diagrams
• Resistor models

6
IV Characteristics

• Resistor
• Bulb
• Diode

7
Resistors

• Thermistor
• LDR

8

• review

9
Mains Elec

• PHET
• AC DC
• Period and frequency

10
Plugs
11
Fuse

• A Fuse is a piece of wire with a low melting
  point
• If there is a fault in the electrical appliance
  and the current goes up it could damage the
  wiring in the appliance
• But if a fuse is installed, this will melt (or
  blow) and break the circuit
• So a fuse is used to protect the appliance not
  necessarily to protect us from electric shock

12
Earth

• What on Earth does it do?
• V d G

13
Earth

• No Earth No Fault

14
Earth

• No Earth - Fault

15
Earth

• Earth no Fault

16
Earth

• Earth - Fault

17
Power

• Power work done / time taken
• Lifting stuff

18
Electrical Power

• Electrical power is the electrical work done in a
  given time.
• Power (W) current (A) x voltage (V)