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Electrical & Electronics Engineering vocabulary · Voltage, Current and Power

RMS

Meaning in electrical & electronics engineering, with examples

abbreviationCommon term

In electrical & electronics engineering, RMS means: Short for root mean square: the effective value of an AC voltage or current, equal to the DC value that would deliver the same power. A mains voltage of 230 V is an RMS value.

In Turkish: etkin değer, efektif değer, RMS

How it is used

Pronounced 'R-M-S'. Used when measuring AC: RMS voltage, RMS current, true RMS meter. For a pure sine wave the peak value is about 1.414 times the RMS value, so 230 V RMS has a peak of about 325 V.

Example sentences

  1. Use a true RMS meter, because the current drawn by the drive is not a clean sine wave.

  2. The output is 12 V RMS, which is about 17 V at the peak.

Common collocations

  • RMS value
  • true RMS
  • RMS voltage
  • RMS current
  • ACShort for alternating current: current that changes direction many times per second. Mains electricity is AC, at 50 Hz in Turkey and Europe and 60 Hz in North America.
  • voltageThe electrical pressure that pushes current through a circuit, in other words the potential difference between two points. It is measured in volts (V).
  • waveformThe shape of a signal when its voltage or current is drawn against time, such as a sine, square, triangle or sawtooth wave.
  • multimeterA handheld or bench instrument that measures voltage, current and resistance, and often continuity, capacitance and frequency as well. It is the most basic tool for electrical testing.

More terms: Voltage, Current and Power

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