NOTE This session was thrown together to replace the GNUCAP session due to problems with getting GCompris installed. I got a bit carried away with Ohms law and prefixes, lost the class, and went to plan B: bring up interesting circuits (high-voltage transmission, spark-gap, 2-way light switch) and talk about them.
You should see the opening screen of the Java-based circuit simulator:
This circuit is a little advanced, so let's start with something simpler.
Open the Circuits menu, select the Basics sub-menu and the Ohm's Law circuit:
You should see a simple circuit demonstrasting one of the fundamental laws of Electronics:
[Ohm's Law], V = I x R
V stands for the voltage across a component. Think of it like the pressure in a water-hose
I stands for the electric current through a comonent. It's like the flow-rate of water through a hose.
R stands for the resistance of a component, something that impedes flow. Think of a kink in a water-hose slowing down the flow.
Hover the mouse over the left-hand resistor and note the details:
Check the math (remember that m is a [prefix] for milli meaning one-thousanths):
I x R = 50mA * 100 Ohm = (50 / 1000) * 100 * A * Ohm = 5V
Double-check with the right-hand resistor (remember that k is a [prefix] for kilo meaning thousand).
Now adjust the Voltage across the resistors with the slider-bar:
You can also adjust the value of the resistors. Right-click on one of them and select Edit:
Now enter a new value and press OK:
And check the results again:
Joule's first Law
Note the P in the last row. That stands for Power:
[Joule's first Law], P = V x I
P stands for the Power dissipated by the component.