Resistors

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What Exactly Is A Resistor?

An Electric Component That Transmits Current In Direct Proportion To The Voltage Across It.

Ohms

The ohm is the unit of resistance. Larger values are measured in kilo-ohms (1000 ohms) and mega-ohms (1,000,000 ohms). Resistors are marked, using a code specified in British Standard 1852, as follows:

  • The letter R means ohm. Numbers coming before the R indicate a value more than one. So 1R (or 1R0) = 1 ohm; 47R = 47 ohms; and 4R7 = 4.7 ohms. Numbers coming after the R indicate a value less than one: so R56 = 0.56 ohms.
  • The letter K means kilo-ohm. Numbers coming before the K indicate a value more than one, while numbers coming after the K indicate a value less than one. So 1K8 = 1.8 kilo-ohms and 5K6 = 5.6 kilo-ohms.
  • The letter M means mega-ohm. Numbers coming before the M indicate a value of more than one, while numbers after the M indicate a value less than one. So 2M = 2 mega-ohms, and 2M2 = 2.2 mega-ohms.
How To Measure Resistance With A Digital Ohm Meter