Search results
Results from the WOW.Com Content Network
As of the 2019 revision of the SI, the ampere is defined by fixing the elementary charge e to be exactly 1.602 176 634 × 10 −19 C, [6] [9] which means an ampere is an electric current equivalent to 10 19 elementary charges moving every 1.602 176 634 seconds or 6.241 509 074 × 10 18 elementary charges moving in a second.
Symbol [1] Name of quantity Unit name Symbol Base units E energy: joule: J = C⋅V = W⋅s kg⋅m 2 ⋅s −2: Q electric charge: coulomb: C A⋅s I electric current: ampere
120 V AC Tungsten incandescent light bulb (60–100 W) 10 0: 1 A Typical iPhone charger (5 W) 1.35 A Tesla coil, 0.76 meters (2 ft 6 in) high, at 200 kV and 270 kV peak [4] 2.1 A High power LED current (peak 2.7 A) [5] 5 A One typical 12 V motor vehicle headlight (typically 60 W) 9 A 230 V AC, toaster, kettle (2 kW) 10 1: 10 or 20 A
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m 2 ⋅s −3. [ 1 ] [ 2 ] [ 3 ] It is used to quantify the rate of energy transfer .
[1] [2] [3] The ampacity of a conductor depends on its ability to dissipate heat without damage to the conductor or its insulation. This is a function of the insulation temperature rating, the electrical resistance of the conductor material, the ambient temperature, and the ability of the insulated conductor to dissipate heat to the surroundings.
The ampere is an SI base unit and electric current is a base quantity in the International System of Quantities (ISQ). [ 4 ] : 15 Electric current is also known as amperage and is measured using a device called an ammeter .
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 ]
The coulomb was originally defined, using the latter definition of the ampere, as 1 A × 1 s. [4] The 2019 redefinition of the ampere and other SI base units fixed the numerical value of the elementary charge when expressed in coulombs and therefore fixed the value of the coulomb when expressed as a multiple of the fundamental charge.