_ .5--- _ . ____ ______ ____ .._ anAC circuit with only a resistor. The graphs show that + there is no phase shift between V H Va the current and the voltage. t la} [b] If a capacitor is connected to an AC source. as shown in Figure 2. the voltage lags the current giving a phase shift of 90\" or LEE cycle. The charge on the capacitor opposes the ow of current through the circuit and stops it completer when full}r charged. This opposition is 1 _ If C is capacitance in Farads: then X: has units given by the capacitive reactance, X 12;: of Ohms. Figure 2 : The diagram shows an AC circuit with only a capacitor. The graphs l shotv the phase shi between V '3 V: the current and the voltage. la] Eh] For AC circuits with a resistor and a capacitor. there is a phase shift between the voltage and the current. The applied source voltage and current will be out of phase hp some amount between I] and 9D\". The size of the phase angle will be determined by the ratio henveen resistance and capacitance. The eect is due to a combined effect of resistance of the resistor, R__ and capacitive reactance Xc- The effect is defined as impedance= E. and is anAC analogue to resistance in a