Electrical Engineering ⇒ Topic : SERIES COMBINATION OF RESISTORS

SERIES COMBINATION OF RESISTORS

When a number of resistors are connected in series, this series combination of resistors can be replaced by an equivalent resistor. In Figure 2.4, three resistors are connected in series. A voltage source of V volt is applied between the ends of the series combination, i.e., beginning of the first and the end of the last. Let the current I flow in the circuit.

From Figure (a), we have

                                                           figure (a)

        ..........    (1)

Let all the resistors connected in series between A and D be replaced by a single resistor having resistance of R Ω, such that the same current I flows through R. It can be written as:

                                                                                                                                                        ...........  (2)

From Eqs. (1) and (2), we get
                                                                                                                                    

If n resistors R₁, R₂, ..........R_n are connected in series, the above equation can be written as:

In series combination

• The current in the circuit is same through all the resistors.
• The voltage across each resistor is different (assuming resistors are of different values).