Electrical Engineering ⇒ Topic : Series Circuits

Series Circuits

A circuit in which two or more loads (resistors) are connected one after the other (in series) is called a series circuit. The resistance of the connecting wires is very small and therefore is neglected in the calculations involving resistor loads.

Series Circuits

A circuit in which two or more loads (resistors) are connected one after the other (in series) is called a series circuit. The resistance of the connecting wires is very small and therefore is neglected in the calculations involving resistor loads.

Example of a series circuit is shown in Fig. (a). The current (I) in the circuit is 2.5 A. The voltages V₁, V₂ and E are 7.5, 12.5 and 20 V respectively.

                                               FIGURE (a) A simple series circuit

By applying Ohm's law, we find that R₁ = V₁/I = 7.5/2.5 = 3 Ω and R₂ = 12.5/2.5 = 5Ω, and the total resistance is E/I= 20/2.5 = 8 Ω

   Also                 E = V₁ + V₂ (by applying Kirchhoff's law)

                          IR = IR₁+ IR₂ (by applying Ohm's law)

Therefore            R= R₁+ R_{2                                 ................ (1)}