what do u mean electrical resistance

The concept of electrical resistance is fundamental to the field of electrical engineering. It's a concept that can be found in virtually every electrical circuit and device, from the simplest of lightbulbs to the most complicated of industrial systems. In its most basic sense, electrical resistance is simply the opposition to the flow of an electric current. Understanding resistance, and how it behaves, can be essential to understanding the full range of electrical phenomena, from the generation of electricity to its usage in everyday devices.

Electrical resistance has been a part of the study of electricity since the late 19th century, when physicist James Clerk Maxwell first formulated a mathematical expression to describe the relationship between current and voltage. Ever since then, this principle has been used to build everything from power plants to cell phones. In this article, we'll take a look at what electrical resistance means, how it works, and why it matters.

At its core, electrical resistance is simply a measure of opposition to the flow of an electric current through a conductor. It is measured in ohms (Ω), which is the symbol for the SI unit of electrical resistance. When a conductor has a higher resistance, this means that it is more difficult for electrical energy to flow through it. As a result, the energy being sent through the conductor is dissipated as heat, and this is one of the reasons why electrical components get hot.

The resistance of any given conductor depends on several factors, including its length, cross-sectional area, and material composition. Different materials have different resistance values, even if they are the same size and shape. For instance, copper has a very low resistance, while rubber has a much higher resistance. This means that the same electrical current will be more easily transferred through copper than rubber.

Resistance also varies with temperature. Generally speaking, the higher the temperature, the higher the resistance. This is because the molecules of a conductor move faster and more frequently as temperature increases, meaning there is more opposition to the flow of electrons. As such, the resistance of a conductor will increase as it heats up. Conversely, the resistance will decrease as the conductor cools down.

In addition to affecting the transfer of electricity, resistance can also affect the voltage across a conductor. When the resistance of a conductor is increased, the voltage drop across it will also increase. This is because of Ohm's Law, which states that the voltage across a conductor is directly proportional to the resistance of the conductor. As such, if the resistance increases, so does the voltage drop.

Finally, resistance can also affect the power output of a device. In general, the higher the resistance of a conductor, the lower the power output. This is because the energy that is generated by a current is dissipated as heat when it passes through a resistor. As such, less power will be available for use if the resistance of the conductor is high.

Overall, understanding resistance is essential to understanding electrical circuits and systems. By knowing how it affects the transfer of electricity, the voltage across a conductor, and the power output of a device, engineers can design more efficient and reliable systems and components. With this knowledge in hand, the possibilities for innovating in the field of electrical engineering are virtually limitless.

Physics Tutorial Electrical Resistance