Husnen Rupani:
As promised, I will show you the series and parallel comparison using these lamps. So let’s start with one lamp first. So right now my supply is set to 12 volts, but it’s turned off. So I will start with the first lamp. So, one lamp connected. If I turn that on, I can see that lamp is turned on, and I’ve got a current of 0.24 or 240 milliamps.

If I connect these lamps in parallel. So, let’s do a parallel connection. Parallel connection is basically each terminal is piggybacked on the other. You can see how the two lamps have the same brightness, and the current has now doubled. Let’s keep going. Same brightness again, but with four lamps the current has now increased by four times, but the voltage is still the same.

Let’s measure the voltage across one of these lamps and see what we get. So to measure the voltage, we’ll use our multimeter here in voltage settings. So, connecting that, that, and as you can see, the voltage is 11.9 or 12 volts. If I was to move that measurement to, let’s say, this last lamp here, I’m still getting 12 volts. Right? So that means that every single one of these lamps is getting the same voltage. Now this is parallel connection.

Let me change this to series connection and see what happens. So now we’ll connect these lamps in series. So we’ll start with the first lamp, and we’ll finish the circuit on the last lamp. So let’s turn the power on. Now at this stage, the circuit isn’t complete because one wire is on this side and the other wire of the power supply is on this side. So, we don’t have a complete circuit.

Let’s continue connecting it. Now, even though this lamp is connected on both sides, it’s not a complete circuit because the current doesn’t have any more parts. So, we’ll keep going. And there now you can see there is a very dim light in each one of these lamps. So when we had these in parallel, all of them had the same brightness and they were quite bright, but now they’re all in series and they’re fairly dim. Let’s measure the voltage across them. Last time when we measured the voltage, it was showing 12 volts. Let’s see what it says now. So now it’s showing 2.8 rather than 12 volts. If I measure the voltage across other lamps, 2.9. Let’s see the last one, and three. So there are roughly three volts each. That’s the difference between series and parallel connection. Thanks for watching.