Charge is the fundamental quantity in electromagnetism. Charge is a characteristic of objects that results from the presence of electrons or protons, as opposed to neutrons.

The electric charge of an object is usually denoted by either Q or ε0, although a variety of other notations are used. Other physical quantities are related to the electric charge, such as electric current and electromotive force.

In technical work on electromagnetism, the charge is defined as an intrinsic property of matter, which has the value Q = 1.6021766 x 10-19 coulomb (C) at rest, where “coulomb” is the SI unit of electric charge.

The ampere-hour (Ah) is another unit of charge equal to 3600 C; when applied to batteries it means “amp-hours”. Electric charges are produced by moving electrical charges or by changing their locations within conductors or dielectrics; they do not exist independently in vacuum or empty space.

The magnitude of charge on any object at rest depends on the amount and type of matter present in it, which may be positive or negative, neutral atoms, ions or free electrons.

Last modified: August 1, 2022