Be sure to check out the Ohm's Calculator to help you determine circuit values.

Ohm's Law

Ohm's Law defines the relationships between (P) power, (E) voltage, (I) current, and (R) resistance. One ohm is the resistance value through which one volt will maintain a current of one ampere.
  Voltage Resistance Amperage or Current Power E times I = P I squared times R = P E squared divided by R = P square root of (P times R) = E P divided by R = E I times R = P E divided by I = P E squared divided by P = R P divided by ( I squared ) = R square root of ( P divided by R ) = I P divided by E = I E divided by R = IOhm's Law

( I ) Current is what flows on a wire or conductor like water flowing down a river. Current flows from points of high voltage to points of low voltage on the surface of a conductor. 

Current is measured in (A) amperes or amps.

( E ) Voltage is the difference in electrical potential between two points in a circuit. It's the push or pressure behind current flow through a circuit, and is measured in (V) volts.

( R ) Resistance determines how much current will flow through a component. Resistors are used to control voltage and current levels. A very high resistance allows a small amount of current to flow. A very low resistance allows a large amount of current to flow. 

Resistance is measured in ohms.

( P ) Power is the amount of current times the voltage level at a given point measured in wattage or watts.

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