Q. Explain Time-Dependent Circuit Analysis?

The response of networks to time-varying sources is considered in this chapter. The special case of sinusoidal signals is of particular importance, because the low-frequency signals (i.e., currents and voltages) that appear in electric power systems as well as the high-frequency signals in communications are usually sinusoidal. The powerful technique known as phasor analysis, which involves the use of complex numbers, is one of the electrical engineer's most important tools developed to solve steady-state ac circuit problems. Since a periodic signal can be expressed as a sumof sinusoids through a Fourier series, and superposition applies to linear systems, phasor analysis will be used to determine the steady-state response of any linear system excited by a periodic signal. Thus the superposition principle allows the phasor technique to be extended to determine the system response of a linear system.

The total response of a system containing energy-storage elements (capacitors and inductors) is analyzed in terms of natural and forced responses (or transient and steady-state responses). The Laplace transformation, which provides a systematic algebraic approach for determining both the forced and the natural components of a network response. The concept of a transfer function is also introduced along with its application to solve circuit problems. The network response to sinusoidal signals of variable frequency is investigated. Also, two-port networks and block diagrams, in terms of their input-output characteristics.