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Kirchhoff's laws

(Encyclopedia)Kirchhoff's laws [for Gustav R. Kirchhoff], pair of laws stating general restrictions on the current and voltage in an electric circuit. The first of these states that at any given instant the sum of ...

electric and magnetic units

(Encyclopedia)electric and magnetic units, units used to express the magnitudes of various quantities in electricity and magnetism. Three systems of such units, all based on the metric system, are commonly used. On...

electricity

(Encyclopedia)CE5 Electrical and radio symbols electricity, class of phenomena arising from the existence of charge. The basic unit of charge is that on the proton or electron—the proton's charge is designate...

electromagnet

(Encyclopedia)CE5 Electromagnet electromagnet, device in which magnetism is produced by an electric current. Any electric current produces a magnetic field, but the field near an ordinary straight conductor is ...

voltaic cell

(Encyclopedia)voltaic cell, a simple device with which chemical energy is converted into electrical energy. Two dissimilar metals (e.g., copper and zinc) are immersed in an electrolyte (e.g., a dissolved sulfate). ...

solar cell

(Encyclopedia)solar cell, semiconductor devised to convert light to electric current. It is a specially constructed diode, usually made of forms of crystalline silicon or of thin films (as of copper indium gallium ...

photoelectric cell

(Encyclopedia)CE5 Photoelectric cell: Light causes a photosensitive surface to emit electrons, which flow as current to the positive terminal. A galvanometer measures the current and thus indicates light intensi...

galvanometer

(Encyclopedia)CE5 Galvanometer galvanometer gălˌvənŏmˈətər [key], instrument used to determine the presence, direction, and strength of an electric current in a conductor. All galvanometers are based upo...

rectifier

(Encyclopedia)rectifier, component of an electric circuit used to change alternating current to direct current. Rectifiers are made in various forms, all operating on the principle that current passes through them ...

telegraph

(Encyclopedia)telegraph, term originally applied to any device or system for distant communication by means of visible or audible signals, now commonly restricted to electrically operated devices. Attempts at long-...