Random Book

Kawaguchi joins the revision session!

"He did put in the effort beforehand... to try and learn electricity earnestly. I'm just trying to... clear it up for him. You're not doing bad either, Kawaguchi-san."

"Heh, thanks. You just explain things well."

It made me wonder. What was I good at?

"If resistors are connected in parallel so that the current will flow through either one or the other, but not both, then the overall resistance is reduced."

"Seriously? I thought it'd increase..." Yukimura said.

"Well, in a parallel circuit, there are different loops the current can take. If the resistors are placed in parallel, the current can follow multiple paths, reducing the resistor's effectiveness. You're not passing through two resistors after all, like in a series circuit."

"Oh, I see. Okay, guess that makes more sense. It's because you're going through a single resistor compared to two and that there are multiple routes for the current to take."

I've always excelled at games. In the end, an exam is just a game, isn't it?

There are winners, there are losers. You can even draw with someone else. There are rules, and there are different methods of attacking and defending. You build your deck - your head - before the battle.

"So let's recap. In parallel circuits: the total current supplied is split between the components on different loops. Potential difference is the same across each loop. The total resistance of the circuit is reduced as the current can follow multiple paths."

By changing my perspective slightly, it makes the exams feel doable.

"The next part is a practical exploring the series and parallel circuits... Um, if you want, I can just explain it to you. I don't feel like going to Ike-sensei's lab when lunch is going to end soon..."

"Yeah, explaining is fine. Make sure to draw some beautiful diagrams!" I said.

"O-Okay. So, this practical has you investigate resistor networks. You have to set up a series circuit like this. It only needs a resistor, an ammeter and a voltmeter in parallel. You record the voltmeter and ammeter readings and use them to calculate the resistance using the equation R = V/I. It's resistance equals voltage divided by current."

Nora drew a diagram of the circuit and then wrote down:

Resistor: R1
Voltage: 4.00
Current: 0.40
Resistance: 10

"Then you repeat this, but this time, you change the resistor for another one to find a resistance of a second resistor."

He then wrote down more readings:

Resistor: R2
Voltage: 4.00
Current: 0.40
Resistance: 10

"Then you'd do it again, but this time have two resistors in series. It would look like this."

Once again, he drew a diagram and wrote some readings down:

Resistor: In series
Voltage: 4.00
Current: 0.20
Resistance: 20

"Notice that by having two resistors, you increase the resistance? It also equals the two resistor readings we put earlier."

That was, admittedly, pretty cool.

"So I'm guessing the next one is parallel?"

"Yep. It'd look like this and the readings would be like this..."

Resistor: In parallel
Voltage: 4.00
Current: 0.80
Resistance: 5

"So in this case, the resistance actually halved from it's original. Analysing this data tells us that in series circuits, the resistance of the network is equal to the sum of the two individual resistances, and in parallel, the resistance of the network is less than either of the two individual resistances."