Answer to Question #299456 in Mechanical Engineering for Apex

Question

An ac circuit consists of a resistance and capacitance connected in series. The result is that

Answer 1

When capacitors are connected in series, the total capacitance is less than any one of the series capacitors' individual capacitances. If two or more capacitors are connected in series, the overall effect is that of a single (equivalent) capacitor having the sum total of the plate spacings of the individual capacitors.

Series Resistance-Capacitance Circuit

In the RC series circuit above, we can see that the current flowing into the circuit is common to both the resistance and capacitance, while the voltage is made up of the two-component voltages, V_R and V_C. The resulting voltage of these two components can be found mathematically but since vectors V_R and V_C are 90^o out-of-phase, they can be added vectorially by constructing a vector diagram.

To be able to produce a vector diagram for an AC capacitance a reference or common component must be found. In a series AC circuit, the current is common and can therefore be used as the reference source because the same current flows through the resistance and into the capacitance.