electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

, a node is any region on a circuit between two circuit elements. In circuit diagrams, connections are ideal wires with zero resistance, so a node consists of the entire section of wire between elements, not just a single point. According to

Ohm's law Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equat ...

, ''V = IR'', the voltage across any two points of a node with negligible resistance is :

V = IR = I\cdot 0 = 0,

showing that the electric potential at every point of a node is the same. There are some notable exceptions where the voltage difference is large enough to become significant: * High-precision resistance measurements using a Kelvin connection * The difference in voltage between ground and neutral, between the

neutral wire Ground and neutral are circuit conductors used in alternating current electrical systems. The ground circuit is connected to earth, and neutral circuit is usually connected to ground. As the neutral point of an electrical supply system is often ...

and the

ground Ground may refer to: Geology * Land, the surface of the Earth not covered by water * Soil, a mixture of clay, sand and organic matter present on the surface of the Earth Electricity * Ground (electricity), the reference point in an electrical c ...

in domestic AC power plugs and sockets, can be fatal. A properly installed electrical system connects them together at only one location, leading many people to the fatally incorrect conclusion that they are at "the same" voltage, or that the safety ground is "redundant and unnecessary" * The Seebeck effect and the Peltier effect * Joints involving

aluminium wire Aluminum building wiring is a type of electrical wiring for residential construction or houses that uses Aluminum conductor, aluminum electrical conductors. Aluminum provides a better conductivity to weight ratio than copper, and therefore is als ...

Dots used to mark nodes on a circuit diagram are sometimes referred to as ''meatballs''.Mansfield, Michael; O'Sullivan, Colm (2010), ''Understanding Physics (2nd edition)'', Chapter 14, page 359, John Wiley & Sons

References

{{Reflist Electricity