Watt's Electricity - Electromagnetism Parallel and Serial Connections

This board expands the understanding of voltage and current by looking at the effect of connection multiple devices in parallel and in series.

Video

Board Image

Tutorial (for when you are with the board)

Part 1

Now we are going to look at volts and amps in some more detail. Look at the board, there are three ammeters to show the flow of current at different points of the circuit. The silver toggle switch can be used to see the voltage across one or both the batteries. Move the switch to position B, this is showing us the number of volts produced by the bottom battery. Now hold down the big red button labelled A down. You will see two of the ammeters show a flow of current and while the first light is on. Note that both meters are showing the same value as the flow is the same round the whole circuit. Now press and hold down buttons A and B. Note that the current round the circuit has gone up. Both lights are now using current. Now press all four buttons and all the lights will come on. Look at the bottom ammeter is twice that of the other two as its takes all current back to the battery.

Part 2

Now every electrical device like these lights is built to use a specific voltage. If it’s given less, it will not work currently and more will mean the device will burn out. All the lights here should be supplied with 1.2 volts. When batteries are connected in series the voltages added together, so here, we can get 2.4 volts. When two lights are connected in series then we need twice the voltage, but the current will be the same as one light. When two lights are connected in parallel the voltage will be the same as for one light, but the current will double.

Research Brief

Find a torch and look at the batteries. Try and work out if they are connected in parallel or series. If the + ends are connected together, they are connected in parallel, if the + and - ends are connected together, they are connected in series. If they are in series, the working voltage of the device will be the voltage of each battery multiplied by the number of batteries.

Follow-Up Ideas

Take the battery cover off a remote control. Most have two batteries, note that the batteries point in different dirrections. That is because they are normally wired in series. This means the unit works on 3 volts - with the voltage of the 2 batteries being added together.
Try and find some christmas tree light. With old sets all the light were wired in series but that meant that if one bulb failed none of the lights would turn on because the circuit was in-complete. The voltage the circuit needed would be the voltage needed by each bulb multipled by the number of bulbs. This always needed to be 240 volts as they were plugged into the house mains. Modern lights are normally LEDs and wired in parallel and so the supply is a very low voltage, details are normally on the plug with changes the voltage to the low value required.
Find the electrical meter (or smart meter) for a house with the help of adult. The rate as which the numbers increase will depend on how much current the house is using. You will see that when an appliance like a kettle is switched on the numbers will increase more quickly.