Kirchoff's Current Law and Kirchoff's Voltage Law

Can anyone explain me the Nodal Point method of finding out current or potential difference in a circuit?

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`2 \times 3`	$2 \times 3$
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`\sum_{i=1}^3`	$\sum_{i=1}^3$
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Comments

Please, have also in mind that Kirchoff's Current Law should be used to each knod EXCEPT ONE due to the overall charge conservation law.

Сергей Кротов - 7 years ago

All nodes in the circuit should express in terms of the node voltages

roland casuga - 7 years ago

thank you :)

Ashesh Choudhury - 7 years ago

It's always good to establish definitions first: A node is defined as a point where any two or more circuit elements (resistor, voltage source, etc) meet.

First, select a node as the reference node. For easier calculations, we usually pick the node that is connected to the most elements. We will say that this node has a voltage of 0, and all other nodes will have voltages with reference to the reference node. This is similar to the "ground" in a circuit. For all other nodes, label their unknown voltage with different variables.

The sum of all currents leaving each node should be 0, according to Kirchoff's Current Law. Using this, we can write equations at each node, adding up all the current that leaves it and setting the sum equal to 0. Now the process for finding the current at each branch varies for different situations. Some problems directly give you the current of each "branch" that is connected to the node. Sometimes, we only know the resistance of a resistor that is connected to the node. If there is a resistor between two nodes, we know the current through the resistor is the difference in voltage potential of the two connected nodes divided by the resistance (Ohm's Law). In other cases, we might have to set new variables for unknown currents. Good problems usually give you enough information to solve for all the unknowns.

Finally, you try to solve a bunch of equations and usually make an arithmetic error somewhere. Hopefully, you can fix it, and tada, you are done!

A few helpful examples: http://www.calvin.edu/~svleest/circuitExamples/NodeVoltageMeshCurrent/

Joanne Lee - 7 years ago

thank you so much :)

Ashesh Choudhury - 7 years ago

heyy can anybody explain mesh current analysis

sakshi rathore - 5 years, 11 months ago

Current entering is equal to current leaving..

Ariel Abing - 7 years ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$