1. Electric Circuits And Voltage
Lesson 6

2. Parts of an Electric Circuit
Every circuit essentially has 4 parts to it.
The source of electrical energy
This can range from a battery, to a generation station.
Electrical Load
Anything that converts electrical energy into whatever form of energy needed. The load is the reason that the electrical load exists

3. Parts of an Electric Circuit
3. Connectors
Anything that conducts electricity, this can include wires to anything that is metal.
4. Electric circuit control device
A simple knife switch, thermostat or any other device that can control the flow of electricity.
When electricity can make a complete circuit it is referred to as Closed Circuit
When electricity cannot make a complete circuit it is referred to as a Open Circuit

4. Electric Circuit Diagrams and Symbols
There are set rules when drawing circuit diagrams, doing this makes them universal for anyone looking at them and it makes them easier to read and follow. It also allows only a few basic symbols to represent many different types of switches, loads and energy sources. The drawings that follow these rules are called Schematic Circuit Diagrams.

5. Electric Circuit Diagrams and Symbols
All lines are drawn straight with right angled corners for turns. All other parts of the circuit follow the symbols shown below.

6. Electric Circuit Diagrams and Symbols
Conductor or wire
To pass current very easily from one part of a circuit to another.

7. Electric Circuit Diagrams and Symbols
Cell-Supplies electrical energy
The positive end is bigger than the negative end.

8. Electric Circuit Diagrams and Symbols
2 Cells

9. Electric Circuit Diagrams and Symbols
DC Source- Electrical energy source
DC = Direct current, always flows one way

10. Electric Circuit Diagrams and Symbols
AC Source - Electrical energy source
AC = Alternating current, continually changing direction

11. Electric Circuit Diagrams and Symbols
Ground –
A connection to earth

12. Electric Circuit Diagrams and Symbols
Switch - An on-off switch allows current to flow only when it is in the closed (on) position

13. Electric Circuit Diagrams and Symbols
Lamp
A transducer which converts electrical energy to light

14. Electric Circuit Diagrams and Symbols
Resistor
A resistor restricts the flow of current,

15. Electric Circuit Diagrams and Symbols
Ammeter
-Device that measures current A

16. Electric Circuit Diagrams and Symbols
Voltmeter
-Device that measures voltage V

17. Electric Circuit Diagrams and Symbols
Motor -electrical load that converts electrical energy into movement M

18. Electric Potential (Voltage)

19. Electric Potential (Voltage)
You cannot see current or voltage directly. The example of water in a pressurized pipe can help you understand how to use these terms.

20. Voltage is the electrical force, or "pressure", that causes current to flow in a circuit. Take a look at the diagram.  Voltage would be the force that is pushing the water (electrons) forward. If the water pressure is increased, more water will flow through the pipe with more energy.

22. Voltage is a way to describe electric energy
Voltage is a way to describe electric energy. Some circuits have a high voltage. Other circuits have a low voltage. Voltage is measured in volts (V). You can measure voltage using a voltmeter or a multimeter.

23. A load converts electrical energy into another form of energy
A load converts electrical energy into another form of energy. You can compare this to the water flowing past a water wheel. The wheel converts some of the energy of the water into motion. The water has more energy before the wheel than after the wheel.

25. Voltage is also called potential difference
Voltage is also called potential difference. When you measure voltage, you measure the difference in electric energy across the load in a circuit.

26. A voltmeter measures voltage across a component of a circuit
A voltmeter measures voltage across a component of a circuit. If you are using a multimeter to measure voltage, your circuit diagram shows the multimeter as a voltmeter.

27. V

28. Measuring voltage in a circuit
You can use a voltmeter to measure across different parts of a circuit.

29. activity Try to make the circuit shown in the diagram.
What voltage does the circuit have?