The power source V, leads electric current I through the resistor R. Thus we can say that the three quantities obey the law of Ohm.

Ohm’s Law relates the **voltage (V)**, the **current (I)** and **resistance (R)**.

Ohm discovered that the current in a circuit is directly proportional to the voltage applied to the edges of a circuit and inversely proportional to the resistance of the circuit.

**V = I x R**

This relationship can be expressed in three ways:

**I = V / R**

**R = V / I**

**V = I x R**

where:

**V **= voltage (Volts)

**I **= current (Ampere)

**R **= resistance (Ohm)

The corresponding relationship between units is: **Ampere = Volts / Ohm**

Thus in a given circuit, the voltage and the current are proportional to each other. This implies that if we double the voltage across the circuit, the current will be doubled; the higher the voltage, the greater the current. However, if we double the resistance of the circuit, the current will reduced by half; the greater the resistance, the less the current.

So by applying the relation V = I x R, if we know any two of the three quantities, we can find the third.

According to Ohm’s law if it is applied potential difference of **1 Volt** to the edges of a circuit having a resistance of **1 Ohm**, will be generate a current of **1 Ampere**.