Define Resistance.

Define Resistance.

Resistance Definition

Resistance refers to the opposition to the flow of electrical current in a conductor. It is measured in units of ohms and is represented by the symbol "Ω". The amount of resistance in a conductor depends on several factors, including the material of the conductor, its temperature, and its length and cross-sectional area. In general, materials with high electrical resistance tend to be poor conductors of electricity, while materials with low electrical resistance are good conductors. Resistance is an important concept in the field of electrical engineering and is often used to design and analyze electrical circuits.

In addition to its role in electrical engineering, the concept of resistance is also important in other fields. For example, in physics, resistance can refer to the opposition of a medium to the flow of a fluid or other substance through it. In biology, resistance can refer to the ability of an organism to withstand harmful influences or to protect itself from disease. In social and political contexts, resistance can refer to the act of opposing or opposing the policies or actions of a government or other authority. In all of these contexts, resistance can involve both physical and psychological processes and can be passive or active in nature.

Resistance Formula and Unit

The formula for resistance is given by Ohm's Law, which states that the resistance (R) of a conductor is equal to the voltage (V) across it divided by the current (I) flowing through it:

R = V / I

The unit of resistance is the ohm (Ω), named after Georg Simon Ohm, who first formulated this relationship. The resistance of a conductor can be calculated by measuring the voltage across it and the current through it and then using the above formula to find the resistance.

For example, if a conductor has a voltage of 10 volts and a current of 2 amperes (A), its resistance would be 10 / 2 = 5 ohms.

It is also possible to use Ohm's Law to calculate the voltage or current in a conductor given its resistance and the other quantity. For example, if we know the resistance of a conductor is 5 ohms and the current through it is 2 A, we can calculate the voltage across it using the formula V = IR, which gives us V = 5 * 2 = 10 volts.