Electrical Circuits

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When voltage is applied to an electrical circuit, current flows in the circuit. The following special relationship exists among the voltage, current and resistance within the circuit: the size of the current that flows in a circuit varies in proportion to the voltage which is applied to the circuit, and in inverse proportion to the resistance through which it must pass. This relationship is called Ohm's law, and can be expressed as follows:

E = I R

Voltage = Current x Resistance

E Voltage applied to the circuit, in volts (V)

I Current flowing in the circuit, in amperes (A)

R Resistance in the circuit, in ohms


In practical terms "V = I x R" which means
"Voltage = Current x Resistance".

1 volt will push one amp through 1 ohm of resistance.

NOTE: E = IR, V=AR, or V=IR are all variations of the same formula. How you learned Ohm's law will determine which one you will use. Personal preference is the only difference; anyone will get you the correct answer.