For series circuit there's only one way for the current to flow in the above circuit. Starting from the positive terminal of the battery, current flow will first encounter R1. From there the current will flow straight to R2, then R3 and finally back to the negative terminal of the battery (Spark fun electronic). .
Parallel circuits happen when 2 components share two common nodes. The current can go through both resistor and split there current, eventually the current will meet back to the negative terminal of the battery. Current through resistor of parallel circuit are the same, and total resistance is 1/RT = 1/R1 + 1/R2 + 1/R3 + _+1/RN (p. 189). Overall when I understand the difference between parallel circuit and series circuit I understand how basics of circuit and then I can move forward to combining more and more nodes in circuits and be able to solve them. .
Kirchhoff's Law.
Kirchhoff's voltage law or KVL is one of two fundamental law in electrical engineering, the other being Kirchhoff's Current Law or KCL. First KVL is a fundamental law, as fundamental as conservation of energy in mechanics, for example because KVL is really conservation of electrical energy. KVL and KCL are the starting point for analysis for any circuit. The basic formula for KVL is a + b + c + d + e + f = 0 as in this formula we can see the electronic charge will eventually become 0 under Kirchhoff's Law. I found this very helpful when I'm solving problems with KVL law because the it will later become 0 so we have a chance to determine our problem solving is right or wrong. Therefore the sum of the voltage differences across all the circuit elements (including the source) is always zero. .
In ECET 110, which covers materials about the function of circuits and its application to computers, is a class that genuinely interests me. After reading the terminal course objectives thoroughly, I expect myself to fully understand all laws, such as Ohm's Law Kirchhoff's law, different types of circuits such as series circuits and parallel circuit, and important theorems like Superposition Theorems and Thevenin Theorem.