Learn Electrical Engineering
Explore key electrical parameters — voltage, current, power, resistance, reactance, and impedance essential for system analysis and design.
The fault calculation is an essential part of power-system analysis. Because it determines the short circuit rating of different electrical components used in the power system. We also design protective-relaying schemes based on the fault levels. For example, a circuit breaker must be capable of making and breaking the fault currents. Additionally, it must withstand … Read more
We shall discuss the construction, uses and working principle of a potentiometer. Errors in Voltmeters Whenever we connect a voltmeter between two points of a circuit, it takes a shunt current depending on its internal resistance. Ideally, the internal resistance of a voltmeter is infinite. However, practically, this resistance is very high but not infinite. … Read more
Wheatstone bridge is a resistance measurement arrangement. It uses four resistors, out of which one is unknown. It measures the unknown resistance with the help of the rest of the three resistors. The Wheatstone bridge consists of these four resistors as the sides of a square, as shown below. Wheatstone bridge with resistors \(R_1\), \(R_2\), … Read more
A positive charge attracts a negative charge. Also, a negative charge attracts a positive charge. It is needless to say the force of attraction depends upon the quantity of charges. Also, it depends on the distance between the charges. Similarly, similar charges repel each other. That means a positive charge repulses another positive charge. Similarly, … Read more
A capacitor is a system where two conducting plates remain face to face with a dielectric medium in between them. When we connect the capacitor across a voltage source, opposite charges accumulate on the two opposite plates. Obviously, the charge of one plate is positive with respect to the charge of the other plate. We … Read more
Normally, two kinds of overvoltage may appear in an electrical system. Power Frequency Withstanding Voltage One type is power-frequency overvoltage. In a three-phase system, a fault in one phase can increase the voltage in the healthy phases to an elevated value. This condition can continue until the clearance of the fault. Also, due to sudden … Read more
Before explaining inductance, let us recall what an inductor is. An inductor is a passive device that opposes sudden change in current through it by inducing an emf across it. Actually, an inductor is a coil of conducting wire. When current flows through an inductor, it produces a magnetic flux around it. Hence, this flux … Read more
An inductor is any type of coil of a conductive wire. We all know from our childhood that when a current flows through a coil, it becomes a magnet. It means that whenever a current flows through the coil, it produces a magnetic flux surrounding it. Obviously, if we change the amplitude of the current, … Read more
Kirchhoff’s Current Law and Kirchhoff’s Voltage Law are two very important laws for solving electrical circuit networks. We use these laws mostly to solve network problems. Kirchhoff’s Current Law Kirchhoff’s Current Law (KCL) says that the total current entering a node equals the total current leaving the node. Obviously, a node is a point where … Read more
In our previous article, we discussed how an inductor behaves in a DC circuit. In this article, we shall discuss how an inductor behaves in an AC circuit. Suppose there is an inductor. We have connected this inductor across an alternating electrical source. The alternating source generates a pure sinusoidal signal. Now, we shall consider … Read more