
reactive elements. If V V
rms
∠
φ
v
and I I
rms
∠
φ
i
are the voltage phasor and current phasor
at load terminals as per the passive sign convention, then the Q delivered to the load circuit
is V
rms
I
rms
sin (
φ
v
–
φ
i
) VAr. The other expressions are relevant when the voltage phasor and/or
current phasor across a pure reactive element is known. In this case (
φ
v
–
φ
i
) is assured to
be 90° if the element is an inductor and –90° if the element is a capacitor. Then, the reactive
power delivered to that element, i.e., Q is given by , where V
rms
is the rms value of the voltage across the element, I
rms
is the rms value of current through
the element and X is the reactance ...