Author: workhouse123

For the first time, Wheatstone (an English telegraph engineer) proposed this bridge for measuring the value of an unknown resistance. This bridge consists of four arms AB, BC, AD, and DC having resistances P, Q, X, and R, respectively (see Fig. 2.22). Resistance P and Q are the known (fixed value) resistances and are called ratio arms. While resistance R is a variable resistance of known…

Gustav Kirchhoff, a German scientist, summed up his findings in a set of two laws known as Kirchhoff’s laws. 2.5.1  Kirchhoff’s First Law Since this law relates the currents following through the circuit, it is also known as Kirchhoff’s Current Law (KCL). This law states that the algebraic sum of all the currents meeting at a…

In fact, a voltage source can be converted into current source and vice versa. Consider a DC source connected to a load resistance RL, as shown in Figure 2.13(a). The source can be treated as a voltage source, as shown in Figure 2.13(b), or as a current source as shown in Figure 2.13(c). Both types of representations appear the same…

The opposition to load current inside the DC source is called its internal resistance. All DC sources (battery, DC generator, or rectifier-type supply) have internal resistance and is represented by Ri. The equivalent circuit of a DC source is the generated emf E is in series with internal resistance Ri of the source as shown in Figure 2.7. Fig. 2.7  (a) Battery…

To operate electrical or electronic circuits, a source of electrical power is required. The basic purpose of a source is to supply power to a load. Therefore, a load is connected to the source as shown in Figure 2.2. The source may be either a DC (direct current) source or an AC (alternating current) source. Fig.…

A simple electric network is shown in Figure 2.1. It contains two voltage sources E1 and E2 and three resistors R1, R2, and R3. In fact, the interconnection of either passive elements or the interconnection of active and passive elements constitute an electric network. Fig. 2.1  An electric network 2.2.1  Active elements The elements that supply energy in an electric network are called active elements.…

The arrangement by which various electrical energy sources, resistance, and other parameters are connected together is called electrical circuit or electrical network. Various laws and theorems have been developed to analyse these simple and complex electrical circuits. One of them, that is, Ohm’s law, has already been discussed in the first chapter. In this chapter, we…