Monopolar

Monopolar describes a configuration having a single conducting pole or electrode. In physics, the term is used for hypothetical isolated magnetic or electric charges; in practice, the magnetic monopole has not been observed, and an electric monopole would correspond to a single excess charge, though isolated charges exist as part of electrical systems.

Magnetic monopoles are hypothetical particles that carry a single magnetic pole. No experiments have confirmed their existence; their discovery would have implications for Maxwell's equations and the quantization of electric charge. Searches have taken place in materials science and particle physics but remain inconclusive.

An electric monopole is simply a net electrical charge. In electrostatics, isolated charges are common in atoms and ions, but a single isolated monopolar source is not a separate component in a typical circuit; rather, circuits employ pairs of electrodes to complete a circuit.

In medical contexts, monopolar electrosurgery uses one active electrode that delivers radiofrequency energy to tissue; current returns through a distant dispersive grounding pad. This method is versatile but carries risks of unintended burns, electrical interference, and requires careful grounding. Bipolar electrosurgery uses two closely spaced electrodes and tends to confine energy to tissue between the tips, reducing some risks.

In electrophysiology and neurophysiology, monopolar recordings refer to measuring electrical activity with a single electrode against a distant reference point; the term contrasts with bipolar recording, which uses two closely spaced electrodes. Monopolar configurations are common in various diagnostic and research settings, though they can be more susceptible to far-field signals and noise compared with bipolar arrangements.