1. Combination Circuits
Lesson 10

2. A simple electric device, like a flashlight, may contain just one series or parallel circuit. However, most of the electric systems you use at school and at home are combinations of series circuits and parallel circuits. This kind of circuit is called a Combination Circuit.

3. In a Combination circuit, the parts of the circuit that are connected in series work like a series circuit. The parts that are connected in parallel work like a parallel circuit. This means that you can design a single circuit to meet several different needs.  

4. Look at the circuit diagram. Then answer the questions below.
Switch 1
Switch 3
Switch 2
Bulb 1
Bulb 2
Bulb 3

5. If all three bulbs are identical, which bulb or bulbs will burn the most brightly in this circuit?
What will happen if bulb 1 burns out?
Bulb 2 will also go out
What will happen if bulb three burns out?
Bulbs 1 and 2 will stay on

6. Which switch controls only one bulb?
Which switch controls two bulbs?
 Switch 2
Which switch controls all three bulbs at once?
Switch 1

7. Where could you connect an ammeter to measure the current through the entire circuit? Mark this location on the circuit diagram.
Switch 1
Switch 3
Switch 2
Bulb 1
Bulb 2
Bulb 3

8. Building a Combination Circuit
Task: Build and draw a circuit that contains two batteries in parallel connected in series to two batteries connected in parallel. Also include a switch that controls one light, a switch that controls two lights, and a switch that controls 4 lights.
What to do
Discuss with your group how you will set up the circuit.
Draw a labelled diagram of your circuit.
 List the materials that you will need to build your circuit.
 Build and test your circuit
Improve your circuit until your group is satisfied with the way it works.