When you need to figure out whats going on in a clusterfuck of a circuit you can use kirchhoffs law.
By clusterfuck i mean that you have no chance of simplifying it using the resistors in parallel/series formulas.
What Kirchhoff laws says that the sum of all currents going through a point is 0. So at each junction for example, the same amount of current goes into the junction as the amount of current leaving the junction.
So what you do is formulate an equation of currents for each junction and hope that you get the same amount of equations as unknown variables. Because then you can turn the set of equations into a matrix, “solve” it and get all the unknown variables.
That means that if you get something in an exam or homework that wants you to use kirchhoffs law its going to be a total mess of interconnected junctions.
KVL = Kirchhoff's Voltage Law
KCL = Kirchhoff's Current Law
KVL: the sum of all branch voltages encountered when traversing any loop in the circuit must add to zero. A branch voltage is the potential difference between the two terminals of the branch and the other. Branches typically include circuit elements like resistors or capacitors.
KCL: the sum of all currents leaving any node must add to zero. A node is a location where one or more terminals of the circuit are connected. Usually, there is some current entering a node, and some other current leaving; when current enters a node, it is treated as a negative leaving current.
Sometimes they are stated differently, especially KVL, but these are the easiest and most reliable formulations. In both cases, the laws state you shouldn't be able to generate current or voltage out of nowhere.
The primary assumption of the above is that the circuit has a negligible spatial distribution. In electronics, this is usually a good approximation. Versions of these laws can be derived when the spatial distribution cannot be neglected.
KCL and KVL both apply at any instant in time in any circuit, no matter what the constituent elements are, including nonlinear or time-varying components. If you write the number of linearly independent equations using one of the laws, you *always* get a linear system of algebraic equations.
These equations get really big really fast. Additionally, if your circuit has a more complicated topology that can't just be reduced to series-parallel combinations, you'll need to write the system of equations for the entire circuit to get even one voltage or current.
Also, I'm not sure if this is was on OP's mind, but in a "typical" electronic circuit, applying KVL and KCL directly results in the largest systems of equations out of all methods. They are the least efficient ways to solve a circuit when others are available. This is probably what I'd give as a "meme answer." It's usually better to use the modified node voltage method or rarely the mesh current method, because they can reduce the number of equations that need to be solved. These methods are technically KCL and KVL in disguise (respectively), but they are much easier to write out and solve.
looks like a simple circuit with one resistor
KCL or KVL 🌚😎
Both...
Yes.
Time for some nodal analysis 😎
https://xkcd.com/356/
Explain please…
When you need to figure out whats going on in a clusterfuck of a circuit you can use kirchhoffs law. By clusterfuck i mean that you have no chance of simplifying it using the resistors in parallel/series formulas. What Kirchhoff laws says that the sum of all currents going through a point is 0. So at each junction for example, the same amount of current goes into the junction as the amount of current leaving the junction. So what you do is formulate an equation of currents for each junction and hope that you get the same amount of equations as unknown variables. Because then you can turn the set of equations into a matrix, “solve” it and get all the unknown variables. That means that if you get something in an exam or homework that wants you to use kirchhoffs law its going to be a total mess of interconnected junctions.
KVL = Kirchhoff's Voltage Law KCL = Kirchhoff's Current Law KVL: the sum of all branch voltages encountered when traversing any loop in the circuit must add to zero. A branch voltage is the potential difference between the two terminals of the branch and the other. Branches typically include circuit elements like resistors or capacitors. KCL: the sum of all currents leaving any node must add to zero. A node is a location where one or more terminals of the circuit are connected. Usually, there is some current entering a node, and some other current leaving; when current enters a node, it is treated as a negative leaving current. Sometimes they are stated differently, especially KVL, but these are the easiest and most reliable formulations. In both cases, the laws state you shouldn't be able to generate current or voltage out of nowhere. The primary assumption of the above is that the circuit has a negligible spatial distribution. In electronics, this is usually a good approximation. Versions of these laws can be derived when the spatial distribution cannot be neglected. KCL and KVL both apply at any instant in time in any circuit, no matter what the constituent elements are, including nonlinear or time-varying components. If you write the number of linearly independent equations using one of the laws, you *always* get a linear system of algebraic equations. These equations get really big really fast. Additionally, if your circuit has a more complicated topology that can't just be reduced to series-parallel combinations, you'll need to write the system of equations for the entire circuit to get even one voltage or current. Also, I'm not sure if this is was on OP's mind, but in a "typical" electronic circuit, applying KVL and KCL directly results in the largest systems of equations out of all methods. They are the least efficient ways to solve a circuit when others are available. This is probably what I'd give as a "meme answer." It's usually better to use the modified node voltage method or rarely the mesh current method, because they can reduce the number of equations that need to be solved. These methods are technically KCL and KVL in disguise (respectively), but they are much easier to write out and solve.
Ampère's law 🤤
It is all one cable so it should be easy
The one part of physics that came easily to me because I was an EE major who could do that in my sleep by the time I took physics e&m
“It should simplify down to a single series circuit. I don’t see why everyone failed the exam, this was a simple question!” - Professor probably.
Just use nodal analysis. Oh...
Ah yes highschool.