Series and parallel circuits - Wikipedia
Components of an electrical circuit or electronic circuit can be connected in many different ways In a parallel circuit, the voltage across each of the components is the same, all of the components in a series connection carry the same current. This is a diagram of several resistors, connected end to end, with the same. Series Circuit: Calculating Voltage Drops with Ohm's Law . The relationship between voltage, current, and resistance is described by Ohm's law. The diagram above will give us the appropriate equation to solve for any. Because the relationship between voltage, current, and resistance in any circuit . so if you see a schematic diagram showing a resistor symbol labeled “load,”.
And this potential energy, as we will see, it is analogous to voltage. Voltage is electric potential, electric potential. Now it isn't straight up potential energy, it's actually potential energy per unit charge. So let me write that.
Potential energy per unit, unit charge. You could think of it as joules, which is potential energy, or units of energy per coulomb. That is our unit charge. And the units for voltage in general is volts. Now, let's think about what would happen if we now open the bottom of this pipe.
Series and parallel circuits
So we open this up. Well, the water's immediately gonna drop straight down. That potential energy is gonna be converted to kinetic energy. And you could look at a certain part of the pipe right over here, right over here. And you could say, well, how much water is flowing per unit time? And that amount of water that is flowing through the pipe at that point in a specific amount of time, that is analogous to current.
Current is the amount of charge, so we could say charge per unit time. Q for charge, and t for time.
And intuitively you could say, how much, how much charge flowing, flowing past a point in a circuit, a point in circuit in a, let's say, unit of time, we could think of it as a second. And so you could also think about it as coulombs per second, charge per unit time.
And the idea of resistance is something could just keep that charge from flowing at an arbitrarily high rate.
Introduction to circuits and Ohm's law (video) | Khan Academy
And if we want to go back to our water metaphor, what we could do is, we could introduce something that would impede the water, and that could be a narrowing of the pipe. And that narrowing of the pipe would be analogous to resistance.
So in this situation, once again, I have my vertical water pipe, I have opened it up, and you still would have that potential energy, which is analogous to voltage, and it would be converted to kinetic energy, and you would have a flow of water through that pipe, but now at every point in this pipe, the amount of water that's flowing past at a given moment of time is gonna be lower, because you have literally this bottleneck right over here.
So this narrowing is analogous to resistance. How much charge flow impeded, impeded. And the unit here is the ohm, is the ohm, which is denoted with the Greek letter omega. So now that we've defined these things and we have our metaphor, let's actually look at an electric circuit.
So first, let me construct a battery. So this is my battery. And the convention is my negative terminal is the shorter line here. So I could say that's the negative terminal, that is the positive terminal.
Associated with that battery, I could have some voltage. And just to make this tangible, let's say the voltage is equal to 16 volts across this battery.
And so one way to think about it is the potential energy per unit charge, let's say we have electrons here at the negative terminal, the potential energy per coulomb here is 16 volts. These electrons, if they have a path, would go to the positive terminal. And so we can provide a path. Let me draw it like this. At first, I'm gonna not make the path available to the electrons, I'm gonna have an open circuit here. I'm gonna make this path for the electrons. And so as long as our circuit is open like this, this is actually analogous to the closed pipe.
The electrons, there is no way for them to get to the positive terminal.
But if we were to close the circuit right over here, if we were to close it, then all of a sudden, the electrons could begin to flow through this circuit in an analogous way to the way that the water would flow down this pipe.
Now when you see a schematic diagram like this, when you just see these lines, those usually denote something that has no resistance. But that's very theoretical. You can use a multimeter to quickly measure the voltage or potential difference in a battery. Image source Voltage comes in two different forms, being DC Direct Current voltage, which provides a steady stream of negative electricity, or AC Alternating Current voltage, which switches from negative to positive continuously.
He also uncovered a ton of other cool things, including: Discovering that if you mix methane with air that you can create an electrical spark, which marked the beginning of the now-famous combustion engine. Discovering that electrical potential stored in a capacitor is proportional to its electrical charge. Volta was also credited with creating the first electric battery, called the Voltaic Pile, which allowed scientists of the time to create a steady flow of electrons.
An example of a Voltaic Pile first created by Volta, enabling scientists to create a steady flow of electrons. Good thing they were wrong! You have your shoes and running shorts on and walk out your door to hit the trail. Maybe an hour into your run and you start to hit your stride, ready to run for miles.
Introduction to circuits and Ohm's law
As you run, your smartwatch measures exactly how far you went and how fast you traveled. This process of running and measuring the process is what Current is all about. Current in Electricity Like taking steps to complete your morning run, current is the constant movement, or flow, of electricity in a circuit. The electric current flowing through your circuit is always measured in Amperes or Amps. But what keeps this current moving?
Just like you need to tell yourself to keep running once you get tired, voltage is the motivating force behind current that keeps it moving.
Under this model, it was assumed that electricity flows from positive to negative. Conventional Flow with electricity flowing from the positive to the negative side of a battery. This model accurately portrays electrons as flowing in the opposite direction, from negative to positive. Because electrons are negative by their very nature, they will always flow out of the negative and endlessly try to find their way to the positive, low voltage side of a power source.
And the more current electron flow, with electrons flowing as they do in reality, from negative to positive. Does it matter which way you display current flowing in a circuit? Image source Ampere was a French Physicist and Mathematician, and also one of the founders of the science of classical electromagnetism. You can thank Ampere for some pretty great stuff, including: His major discovery of demonstrating that wire carrying an electric current can either attract or repel another wire that also has a current flowing through it, without the use of physical magnets.
He was also the first to bring out the idea of the existence of a particle that we all widely recognize as the electron. Instead, his father let him do as he pleased, learning anything. While this might bring out laziness and excessive video game playing in the rest of us, Ampere discovered a natural love for knowledge, devouring as many books as he could from the family library and even memorizing pages from the encyclopedia. Imagine yourself back out on the running trail, on what kind of surface are you running?
Or maybe you prefer the firmness of the street or sidewalk. But what if it starts pouring outside? Naturally, not every path of resistance is created equal. Running through mud puts way more resistance on your ability to run when compared to running on a dirt path or street.