Ohm’s Law

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).

Ohms_law

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.