Therefore, they cannot be added like ordinary
numbers The two voltages are out of phase by ninety degrees Therefore, the total of these voltages must be obtained using the
Pythagorean theorem:
2
2
R C
R
C
V
V
V
+
=
+
= 220 V
Thus, if the phase difference between two voltages is properly taken
into account, the total voltage across the resistor and the capacitor
is equal to the voltage of the source EXAMPLE 7