Question: What is the SI base unit of electric current?
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The ampere.
The SI (International System of Units) base unit of electric current is the “ampere,” commonly abbreviated as “A.” Established as a fundamental unit of the SI system, the ampere represents the flow of electric charge through a conductor.
The formal definition of the ampere has evolved over time. Traditionally, it was defined through the force between two parallel current-carrying conductors. When a constant current of one ampere flows through two infinitely long, parallel conductors placed one meter apart in a vacuum, it produces a force of exactly 2 x 10^-7 newtons per meter of length between the wires.
However, in 2019, the definition of the ampere was updated as part of a broader revision of SI base units. The ampere is now defined by taking the fixed numerical value of the elementary charge e to be 1.602176634 × 10^-19 coulombs. This redefinition is based on the charge of a single electron, providing a fundamental connection between the macroscopic world of electric currents and the quantum world of elementary particles.
In daily life, the ampere is a crucial unit, foundational to our understanding of electrical phenomena and used widely in electrical and electronic measurements.
