# Junction in Electrical Circuit | Electrical Nodes and Junctions

Contents

Junction in electrical circuit is sometimes misunderstood slightly with node in electrical circuit.

• The place where the terminals of two or more circuit elements connect, as well as any wires or conductors between them, is known as a node.
• The definition of a node is agreed upon by all.
• Any point in a circuit where current separates is generally referred to as a junction.

A junction is also known as a node that connects three or more circuit elements. Elements are black, nodes are colored, and junctions are black dots between elements or wires, according to the most accepted definitions.

## Node in Electrical Circuit

A point in a circuit where two or more circuit elements meet is known as an electrical node. A resistor, capacitor, transistor, and other elements are examples of elements.

Each element has terminals, which are conductors that extend from the element’s body. The element connects to the circuit through terminals.

Terminals are the conductors that allow the element to connect to the circuit.

A node is the point at which the terminals of two elements meet.

If there are cables connecting the terminals, the wires are also considered part of the node. The full span of the circuit with no difference in voltage is also referred to as a node (i.e. no resistance). A node is represented with a certain color. This circuit consists of three nodes.

Three nodes connect the items in the circuit above:

1. First node (blue) is formed by resistors R1, R2, and R3 and the terminals of the DC voltage source V1. The terminals are in black because they aren’t technically part of the node.
2. Second node (green) is between the terminals of resistor R3 and capacitor C1.
3. Third node (red) is between the terminals of the DC voltage source V1, the resistors R1 and R2, and the capacitor C1.

## Junction in Electrical Circuit

This is when things become a little complicated. The phrase electrical junction has slightly distinct definitions in physics (scientists) and engineering (engineers).

Our focus here will be junction in electrical circuit.

Physicist:

A junction is any place in a circuit where a current can split, according to physics. Junctions, unlike nodes, are points.

The wires of equal voltage around the junction are not included in junctions (whereas nodes are both the point of connection and any connecting wires between terminals).

In fact, they can serve as a point of connection between elements and cables. The current can split anywhere. The black dots in the circuit above represent junctions.

There are three (3) nodes in the circuit, however there are five (5) junctions. This is the most common definition of a junction found in textbooks.

Engineer:

Engineers (engineers): They sometimes agree with scientists and sometimes disagree with them. Engineers will periodically rewrite things to make their jobs easier.

Engineers frequently claim that a junction IS a form of node with at least three connected pieces when they disagree with physicists. A junction is a type of node in this definition.

A node must have at least two connecting pieces, but a junction must have at least three.

Engineers, on the other hand, sometimes leave the connecting wires out when defining junctions in this manner. Engineers may use the term “point” to refer to both nodes and junctions (rather than the whole interconnecting wire).

But there are another definition we should consider:

A location or area where many conductors or semiconductors make physical contact is referred to as an electrical junction. Thermoelectricity junctions, metal–semiconductor junctions, and p–n junctions are examples of electrical junctions.

There are two types of junctions: rectifying and non-rectifying. Ohmic contacts are non-rectifying junctions. P–n diodes, Schottky diodes, and bipolar junction transistors are examples of electronic components that use rectifying junctions. (Receptacles for electricity)

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## Is There a Difference Between Node and Junction in Electrical Circuit?

In most cases, the distinction between nodes and junctions is irrelevant. They’re both representations of circuit connections.

Unless they’re talking about two junctions within the same node, you’ll get the same answer if you ask for voltage differential between two nodes or junctions.

The voltage would be zero in this situation, and it would be a trick question or a mistake.

When a distinction is critical, you can immediately determine what the other person (or book) is referring to. Scientists and engineers, for the most part, strive to be as exact as possible.

They’ll frequently phrase a question by naming specific locations or pieces, such as the ‘Junction at Point A’ or the ‘Node between R1 and R3,’ so you can figure out exactly what they’re talking about.

## When Should You Use Nodes?

When applying Kirchoff’s Current Law, nodes are usually safer and easier to employ than junctions (KCL). You may need to break up the circuit into smaller portions if you use junctions.

You’ll wind up putting in more effort to achieve the same result. For example, you could use KCL to evaluate each junction in a parallel circuit like the one above, but you’d wind up with two extra equations (one for each junction of the first two current branches).

After that, you’ll have to figure out how to solve for each unknown current. You’ll have more equations, but you’ll also have more unknowns. It simply makes your life more difficult. For a reason, KCL is also known as the nodal rule.

## When Should You Use Junction?

While studying a loop, for example, when utilizing Kirchhoff’s Voltage Law (KVL). You may easily specify the loop’s boundaries by using the junction in electrical circuit as corners when possible.

This makes it simple to build up the KVL equations and avoids any ambiguity.