Week 3: Nodes, Branches, Loops, & Kirchoff's Laws

Nodes, Branches, & Loops

What are Nodes, Branches, & Loops?

Branch- A branch represents a single element such as voltage source or a current source or a resistor.

Node- A node is the point of connection between two or more branches.

Loop- A loop is any closed path in a circuit.

Kirchoff's Current Law (KCL)

This fundamental law results from the conservation of charge. It applies to a junction or node in a circuit -- a point in the circuit where charge has several possible paths to travel.

In Figure 1, we see that IA is the only current flowing into the node. However, there are three paths for current to leave the node, and these current are represented by IB, IC, and ID.

Once charge has entered into the node, it has no place to go except to leave (this is known as conservation of charge). The total charge flowing into a node must be the same as the the total charge flowing out of the node. So:

IB + IC + ID = IA

Bringing everything to the left side of the above equation, we get

(IB + IC + ID) - IA = 0

Kirchoff's Voltage Law (KVL)

Kirchhoff's Voltage Law (or Kirchhoff's Loop Rule) is a result of the electrostatic field being conservative. It states that the total voltage around a closed loop must be zero. If this were not the case, then when we travel around a closed loop, the voltages would be indefinite. So:

In Figure 1 the total voltage around loop 1 should sum to zero, as does the total voltage in loop 2. Furthermore, the loop which consists of the outer part of the circuit (the path ABCD) should also sum to zero.

Resistor Color Code

We are able to use solve resistance by using the Resistor Color Code

Reflection:

In the 3rd week of our CpE 311 subject, I learned to identify the Nodes, Loops, & Branches of an Electric Circuit. I have also learned that according to Kirchoff's Current Law, A current that enters a circuit is equivalent to a current that leaves a circuit and lastly, I have also learned how to measure the resistance of a resistor using the Resistor Color Code that was discussed in our Laboratory Class.

Videos:

Nodes, Branches, & Loops:

 

Kirchoff's Current Law (KCL):

Kirchoff's Voltage Law (KVL):

I apologize for the delay of my submission. This is because of the non-stop electrical brownouts that keeps on happening in our area -_-" . Also, starting from this post, I will also be adding quotes in my blog. I believe these quotes will help me understand and be truly inspired at the beauty of our CpE 311 subject. Hope you enjoy them as much as I do :D Thank you for visiting my Blog once again and God bless to All XD.

A lot of words in English confuse the idea of life and electricity, like the word "Livewire".

-Laurie Anderson