Resistance in Series

If we link resistors across a source such that the final point of one resistor is joined with beginning point of the other resistor then they are called to be connected in a series. The joint effect of all of the resistors will be equivalent to the total of individual resistances.

            Let two resistances R1 and R2 having terminals A, B and C, D as indicated in the figure.

                They shall be in series if we connect B with C as indicated in the figure

 Joint effect of these two resistances will be         

                                                            R_eq = R₁ +R₂

            Then, if we connect N resistances in series then

                                                R _eq = R₁+R₂+R₃+.......+R_N