Page 383 - Basic Electrical Engineering

and a spring stores energy when it is elongated or compressed.
An electric circuit generally consists of circuit elements like resistance,
inductance, and capacitance. The voltage and frequency are generally

constant at the supply terminal. However, in electronic communication
circuits, the supply voltage may have variable frequency. When frequency is

variable, the inductive and capacitive reactance of the circuit elements will

change The current in the circuit will depend upon the

values of X and X and that of R. A condition may occur at a particular
L
C
frequency that the impedance offered to the flow of current is maximum or
minimum. The circuit elements, namely the inductance element and the

capacitance element are often connected in series or in parallel. It will be
interesting and also useful to study the effect of varying input frequency on
the circuit condition when these elements are connected in series or in

parallel.

3.3.1 Resonance in AC Series Circuit

Let us consider a series circuit consisting of a resistor, an inductor, and a
capacitor as shown in Fig. 3.66 (a). The supply voltage is constant but its
frequency is variable.