Search results
Results from the WOW.Com Content Network
The volt-ampere (SI symbol: VA, [1] sometimes V⋅A or V A) is the unit of measurement for apparent power in an electrical circuit. It is the product of the root mean square voltage (in volts) and the root mean square current (in amperes). [2] Volt-amperes are usually used for analyzing alternating current (AC) circuits.
A series circuit with a voltage source (such as a battery, or in this case a cell) and three resistance units. Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel topology.
In such cases, voltage converters need only be specified to convert any voltage within one range, to a voltage within the other, rather than separate converters being needed for all possible pairs of nominal voltages (110–220, 117–220, 110–230, etc.)
In North America and northern South America, it is usually 120 volts, 60 hertz (Hz), but in Europe, Asia, Africa, and many other parts of the world, it is usually 230 volts, 50 Hz. [2] Aircraft often use 400 Hz power internally, so 50 Hz or 60 Hz to 400 Hz frequency conversion is needed for use in the ground power unit used to power the ...
A log amplifier, which may spell log as logarithmic or logarithm and which may abbreviate amplifier as amp or be termed as a converter, is an electronic amplifier that for some range of input voltage has an output voltage approximately proportional to the logarithm of the input:
Historically the "conventional" volt, V 90, defined in 1987 by the 18th General Conference on Weights and Measures [3] and in use from 1990 to 2019, was implemented using the Josephson effect for exact frequency-to-voltage conversion, combined with the caesium frequency standard. Though the Josephson effect is still used to realize a volt, the ...
In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V), meaning the watt is equivalent to the volt-ampere (the latter unit, however, is used for a different quantity from the real power of an electrical circuit).
where is the current, measured in amperes; is the potential difference, measured in volts; and is the resistance, measured in ohms. For alternating currents , especially at higher frequencies, skin effect causes the current to spread unevenly across the conductor cross-section, with higher density near the surface, thus increasing the apparent ...