Why do we consider ‘I’ as conjugate? What is its necessity?please elaborate in brief
When you multiply two complex quantities in polar form, their magnitude gets multiplied but the angles are added.
If you don’t consider conjugate see what happens,
S = V∠θv I∠θi
Where, V and I are in polar forms.
S = VI∠(θv+θi)
If you convert polar form into rectangular form
S = VI Cos(θv+θi) + i VI Sin(θv+θi) S = P + iQ
P = VI Cos(θv+θi) which is not what we wanted and it is not equal to the one we’ve learned earlier.
To way around this we use conjugate operation in S = VI* to make (θv-θi).
Thank you for your explanation