
The infinity symbol, a mathematical concept introduced by John Wallis in the 17th century, is often used in electrical terms. In electronics, the term 'infinity' is used to describe an insulated gate field-effect transistor (IGFET), which has an insulated gate and nearly infinite gate-channel resistance. Ohmmeters, which test electrical resistance and current, also use the infinity symbol to indicate an open circuit. The phrase relative to infinity is used in electrostatics to refer to setting the potential to zero at infinity, or defining the ground of an electrical system.
Explore related products

Voltage difference
Voltage, also known as electrical potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. The volt (V) is the standard unit for voltage. It is named after the Italian physicist Alessandro Volta, who possibly invented the first chemical battery.
Voltage can be understood as the potential energy difference per unit charge between two points in an electrical field. One point has a higher potential, and the other has a lower potential. The difference in charge between these two points is what we call voltage or potential difference. The higher the voltage, the greater the force, and therefore the more electrons flowing through the circuit.
The hydraulic analogy is a useful way to understand voltage. In a hydraulic system, higher pressure pushes water through pipes, similar to how voltage pushes electrons through a circuit. In a water tank, the water level is equivalent to voltage or potential difference. If the water level in the tank increases, more pressure is developed at the end of the hose. Conversely, if the water level in the tank decreases, the pressure at the end of the hose will also decrease.
In a static electric field, voltage corresponds to the work needed per unit of charge to move a positive test charge from one point to another. The voltmeter is an instrument used to measure voltage. It is connected to the two points in the system to determine the voltage between them.
Understanding 'In Phase' Electrical Concepts: Meaning and Applications
You may want to see also
Explore related products
$104.66 $129.99

Electric field
In electrical terms, infinity is a complex concept that often arises when discussing voltage, electric fields, and potential energy. Let's delve into the details of electric fields and their relationship with infinity.
The electric field is a fundamental concept in electromagnetism, describing the influence that a charged particle exerts on the space surrounding it. This field can extend over a certain distance, and its strength decreases as you move away from the charged particle. The inverse square law for an electric field is given by:
> E = Q / (4π∈₀r^2)
Where E represents the electric field, Q is the charge, ∈₀ is the vacuum permittivity, and r is the distance from the charge. This equation demonstrates that as the distance (r) increases, the electric field strength decreases.
Now, when considering the concept of infinity, one might think about extending the distance (r) to infinity in the equation. Interestingly, even if you extend the range of the electric field to infinity, the energy associated with the electric field remains finite. This is a crucial insight: electric fields can have an infinitely large range, but their energy does not become infinite.
However, it is essential to distinguish between different dimensions when discussing infinity in electric fields. In two or one-dimensional cases, the electric field decreases at a slower rate (inversely proportional to the distance), leading to a potential energy that is infinite. This means that in a two-dimensional scenario, objects thrown apart would theoretically reach infinite speed due to the infinite potential energy.
The concept of "relative to infinity" is also important in electrical contexts. It implies setting the potential to zero at infinity, serving as a boundary condition when integrating the field to determine the potential. This concept is akin to choosing the "ground" reference point in an electrical system.
In summary, while electric fields can extend to infinity, their energy remains finite due to the inverse square relationship between field strength and distance. However, in lower dimensions, the potential energy can become infinite, leading to intriguing theoretical scenarios. The concept of "relative to infinity" helps establish reference points for voltage and potential in electrical systems.
Understanding Electrical In-Conduit Wiring: What, Why, and How?
You may want to see also
Explore related products

Inductance
Electromagnetic induction, first described by Michael Faraday in 1831, is the process by which a changing magnetic field induces a voltage in a conductor. Faraday's experiment involved wrapping two wires around opposite sides of an iron ring. He observed that when a current started to flow in one wire, a transient current was induced in the second coil of wire each time a battery was connected or disconnected from the first coil. This phenomenon is known as self-induction, and the induced voltage opposes the change in current that created it, as described by Lenz's law.
The term inductance was coined by Oliver Heaviside in 1884 as a convenient way to refer to the "coefficient of self-induction". The symbol for inductance is "L" in honour of the physicist Heinrich Lenz. The unit of inductance in the SI system is the henry (H), named after Joseph Henry, who discovered inductance independently of Faraday. One henry is defined as the amount of inductance that causes a voltage of one volt when the current is changing at a rate of one ampere per second.
Understanding Electric Tables: IMC, EMT, and Their Meanings
You may want to see also
Explore related products

Resistance
The magnitude of resistance in a circuit depends on several factors, including the materials used, the geometry of the components, and the temperature. For instance, a thicker wire will generally offer less resistance to the flow of current than a thinner one, all else being equal. Additionally, certain materials, known as insulators, possess inherently high resistance and are specifically employed to impede the flow of electric current. Examples of insulators include substances like rubber, plastic, and wood.
In contrast to insulators, conductors are materials that possess low resistance and facilitate the easy flow of electric current. Copper and aluminium are common examples of conductors used in electrical wiring due to their ability to minimise resistance.
Ohmmeters are instruments used to measure resistance in electrical circuits. They come in various shapes and sizes and are invaluable tools for identifying defective components in a circuit. When using an ohmmeter, the infinity symbol (∞) indicates an open circuit, signifying that there is no continuity between the two test leads.
Incandescent Bulbs: How Do They Work and What Do They Mean?
You may want to see also
Explore related products
$29.99

Relative to infinity
In electrical terms, the phrase "relative to infinity" is used to describe a specific way of defining voltage. Voltage, in this context, refers to the voltage difference between two points, often with one of the points being "ground" or Earth. This concept is particularly interesting in physics because voltage can be meaningfully defined at each point in space and remains the same regardless of the path taken to reach that location.
"Relative to infinity" implies that the arbitrary constant in the voltage equation is set so that it becomes zero very far away from the charges. In other words, if you were to consider a scenario where all of space only contained four charges, the phrase "relative to infinity" would indicate that the voltage at a location infinitely far away from those charges is defined as zero. Consequently, the voltage at any other location is linearly related to the work required to move a charge from that distant point to the location in question.
This concept of setting the potential to zero at infinity serves as a boundary condition when integrating the field to obtain the potential. It establishes the "ground" reference point for your electrical system. Thinking about it in this way provides a simplified approach to choosing the gauge for your electromagnetic system.
It's important to note that the voltage being zero does not imply that the electric field is also zero. To illustrate this, consider standing on top of a smooth hill. Even if the slope at the top of the hill is flat, you know you're on a hill because of the effort it took to climb to that point, not because of the flatness or lack thereof. Similarly, the voltage at a location is influenced by the work done to bring a charge to that point, regardless of the electric field strength.
Inductive Electricity: Understanding the Basics of Inductance
You may want to see also
Frequently asked questions
When an ohmmeter points to the infinity symbol, it means that there is no continuity between the two test leads and that an open circuit is present.
An ohmmeter is a device that tests the electrical resistance and current between two leads.
"Relative to infinity" refers to setting the potential to zero at infinity. It is the boundary condition that results when integrating the field to obtain the potential.
An Insulated Gate Field Effect Transistor (IGFET) is a type of transistor with an insulated gate and nearly infinite gate-channel resistance.











































