# How Are Complex Numbers Used In Electrical Engineering?

The conjugate of a complex number is a crucial component in determining the apparent power of an AC circuit in rectangular shape in Electrical Engineering.

## In engineering, how may complex numbers be used?

Electrical and electronic engineers employ complex numbers to establish the Alternating Current or AC concept of Impedance, and Fourier analysis is used in the processing of radio, telephone, and video signals; see this page for additional information.

Mechanical & Structural Engineers use complex numbers to analyse the vibration of structures in machines, buildings and bridges, the behaviour of fluid flow around aircraft, and that of wind around buildings and bridges, preventing failures such as the Tacoma Narrows Bridge (Please watch the following video).

The Mandelbrot set, a type of 2D fractal geometry depicted in the figure below, is based on complex numbers.

## Do electrical engineers make use of fictitious numbers?

Because complex numbers are an intrinsic aspect of electrical difficulties, imaginary numbers are used in electrical engineering. In fact, in electrical engineering difficulties, there are typically more imaginary numbers than real numbers. This is because a complex number is made up of two integers, one of which is real and the other imaginary (or a real number multiplied by the value I which is defined as the square root of -1; see “Math Basics” for more information on imaginary numbers).

For example, we know that electricity travels via a light bulb in an electrical circuit. By doing workor shiningthe bulb really fights the flow of some electricity, resulting in a genuine current that can be measured with a current meter. However, if a device prevents the current from flowing, the current becomes illusory. A capacitor, for example, is two pieces of metal that do not touch; as a result, when a voltage is applied, no real current can flow through it.

## In electromagnetism, how are complex numbers used?

Quadratics with zeroes can be solved using complex numbers. For the values of x, the quadratic formula solves ax2 + bx + c = 0. Complex numbers can be used to simplify the zero if the formula produces a negative in the square root.

Electronics and electromagnetism both require complex numbers. A single complex number combines two real numbers, making them easier to manipulate. In electronics, for example, the voltage (V) and current (I) define the state of a circuit element (I). The capacitance (c) and inductance (L) of circuit elements describe the circuit’s tendency to resist changes in V and I. Rather than V and I, the state of the circuit element can be stated as z = V + Ii. The addition and multiplication of complex numbers can then be used to explain the rules of electricity.

This can also be used to electromagnetism, as previously stated. Instead of being expressed as electric field strength and magnetic field strength, a complex number can be created with real and imaginary values for the electric and magnetic components.

## In AC circuits, how are complex numbers used?

The mathematics of complex numbers can be applied to AC currents and voltages if complex numbers are utilized to describe sinusoidal currents and voltages.

The current phasor via aresistance would be if an AC voltage is given by V = V (resistance does not induce a phase shift).

and the phase angle shows that the current is 90 degrees behind the voltage.

As a result, the complex number determines the effect of inductive reactance.

For the purely capacitive circuit, repeat the procedure. To a fully capacitive circuit, apply the following voltage:

The phase angle demonstrates that the current is 90 degrees ahead of the voltage.

As a result, the complex number determines the effect of capacitive reactance.

The results given in the picture below are obtained by plotting resistance, capacitive reactance, and inductive reactance on a complex plane.

## How are complex numbers employed in everyday life?

In AC circuits, complex numbers are also used to calculate current, voltage, and resistance (AC stands for Alternating Current, which is a current that changes magnitude and direction over time). The potential difference between two AC power supply with respect to time is a typical application of complex numbers (more specifically, Euler’s formula). An example of such a calculation can be found on the right.

Simply combining VA and VB together will not yield the combined potential difference. Both voltages, on the other hand, can be expressed as the Real Part (x-coordinate on the Argand Diagram) of a complex number.

*To avoid confusion with current, it is customary to use j instead of I to indicate imaginary values in circuit analysis (which its symbol is I or I).

Furthermore, in an AC circuit, complex numbers are utilized to express the magnitude and phase of impedance. Impedance works in the same way as resistance in that it slows down electrons in a circuit. The difference is that impedance causes the electrical current to phase shift, whereas resistance does not. Impedance occurs in everyday electrical components like inductors and capacitors, therefore knowing how to represent it with a complex number is essential. In general, complex numbers are used to represent phase, which is important for studying AC circuits.

## In quantum physics, how are complex numbers used?

Complex numbers are highly useful for modeling periodic processes, especially when dealing with phase discrepancies. A physical quantity can be treated as complex mathematically, but physical significance can only be addressed to its real part.

## Is there any application of complex numbers in mechanical engineering?

Laplace transformations are used in control theory to transfer systems from the time domain to the frequency domain. In the complex plane, the system’s poles and zeros are examined.

Signal Analysis: In signal analysis and other domains, complex numbers are utilized to create a suitable description of periodic signals. We can study equivalent complex functions whose real components are the original quantities for specified real functions that reflect physical quantities, commonly in terms of sine and cosine. The absolute value |z| of the corresponding number z is the amplitude, and the argument, arg(z), is the phase, for a sine wave of a certain frequency.

Improper integrals: When employing complex number functions to calculate improper integrals with real-life values in practical domains like engineering, complex numbers are frequently used.

Mechanical and Civil Engineering: In the construction of buildings and automobiles, the concept of complex geometry and the complex plane is extremely valuable. This notion is applied in the design of buildings and automobiles in two dimensions. In mechanics, complex numbers can be used to represent rotations.

Residuals Theorem: The residuals theorem in complex analysis is a powerful tool for evaluating path integrals of meromorphic functions with respect to closed curves and can often also be used to calculate real integrals.

## What does electricity’s math entail?

Electricity Measurement One ampere (a unit of electric current) traveling at one volt equals one watt of electricity (a measure of electrical force). Electricity in American houses is supplied at 120 volts. To light up a 60-watt light bulb, half an ampere of current is required.