
94
the power dissipated is represented by the phasor that is parallel to
the current phasor: ac in Fig. 6.10Z?. In terms of the total voltage, this
voltage is ab. ac/ab, or ER/Z. So
* ~ Ζ
Ε and / being the total voltage and the current.
In trigonometry the ratio ac/ab is called the cosine of the angle φ,
abbreviated to cos φ. So another form of the same equation is
Ρ = EI cos φ
φ being the phase angle between Ε and /. Cos φ is known to electrical
engineers as the power factor.
6.10 Capacitance and Resistance in Parallel
In solving this type of circuit, Fig. 6.11, we revert to the practice of
starting with the voltage, because that is commo