Page 302 - Basic Electrical Engineering
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or,
or,
where
Thus, we observe that in a purely inductive circuit
v = V sin ωt
m
and
= I sin (ωt − 90°)
m
The current, i is also sinusoidal but lagging behind, v by 90°. The voltage
and current wave shapes have been shown in Fig. 3.14 (b). The instantaneous
power, p is the product of v and i. The wave shape of instantaneous power
has also been shown in the figure. The phasor diagram of RMS values of v
and i has been shown in Fig. 3.14 (c). In a purely inductive circuit current, I
lags the voltage, V by degrees, i.e., 90°.
Power factor, cosϕ = cos 90° = 0
Average power
