Combination of Resistances in Series

Combination of Resistances in Series

Resistance in a conductor can be defined as the opposition offered to the flow of electrons. Resistance can be joined to each other in two ways:

1. Series Combination:

If resistances are connected in series, such that the current flowing through them is the same, the resistances are said to be in series. If I is the current flowing through the resistances, then potential drop across each is:

Series Combination

If different resistances are joined with each other such that there is only one path for the flow of electric current then the combination of such resistances is called Series Combination.

V₁ = IR₁; V₂ = IR₂; V₃ = IR₃

Adding, V₁ + V₂ + V₃ = I (R₁ + R₂ + R₃) … (1)

But, V₁ + V₂ + V₃ = V, so we get from equation (1): V = I (R₁ + R₂ + R₃)

Where V is the potential difference across the combinations, also from ohm’s law: V = IR

From equations (1) and (2), we get:

R = R₁ + R₂ + R₃

Where R = Equivalent resistance.


1.In series combination Potential difference across each resistor is different depending upon the value of resistance.

2. The equivalent resistance of a circuit is equal to the sum of individual resistances.

3. In series combination current through each resistor is constant.