Electrical Engineering ⇒ Topic : Subtraction of Alternating Quantities

Subtraction of Alternating Quantities

If difference of two phasors is required, then one of the phasors is reversed and this reversed phasor is then compounded with the other phasor using parallelogram method or method of components.

                                                                   figure   (a)

Consider two phasors OA and OB representing two alternating quantities of the same kind [See Fig. a (i)]. The phasor OB leads the phasor OA by 0. If it is required to subtract the phasor OB from OA, then OB is reversed and is compounded with phasor OA as shown in Fig. a (ii). The phasor difference 0AOB is given by the phasor OC. In Fig. a (iii), phasor OC represents the phasor difference 0B-0A.