Siemens (unit) plural. For a conducting element, electrical resistance "R" and electrical conductance "G" are defined as where "I" is the electric current through the object and "V" is the voltage (electrical potential difference) across the object. The unit siemens for the conductance "G" is defined by where Ω is the ohm, A is the ampere, and V is the volt. For a device with a conductance of one siemens, the electric current through the device will increase by one ampere for every increase of one volt of electric potential difference across the device. The conductance of a resistor with a resistance
Electric current wire he deduced that the heat produced was proportional to the square of the current multiplied by the electrical resistance of the wire. This relationship is known as Joule's First Law. The SI unit of energy was subsequently named the joule and given the symbol "J". The commonly known unit of power, the watt, is equivalent to one joule per second. In an electromagnet a coil, of a large number of circular turns of insulated wire, wrapped on a cylindrical core, behaves like a magnet when an electric current flows through it. When the current is switched off, the coil