Electrical Resistance

What is electrical resistance?

Electrical Resistance is the property of material which opposes the flow of current passing through it.

What is the unit of resistance?

The unit of resistance is the ohm (Ω), named after the German physicist Georg Simon Ohm.

What is Ohm’s law?

Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

V ∝ I

What is resistance formula?

The resistance formula is a mathematical equation used to calculate the resistance of a conductor or circuit component and it is given by:

R = V/I

Where,

• V is the potential difference across the conductor (in Volts),
• I is the current through the conductor (in Amperes) and
• R is the constant of proportionality called Resistance (in Ohms).

How is the resistance of a wire affected by its length and cross-sectional area?

As The relationship between resistance, length and cross sectional area of a conductor is described by the formula 

R = (ρL)/A

Where 

• R is resistance, 
• ρ is the resistivity of the material, 
• L is the length of the wire, and 
• A is the cross-sectional area of the wire.

Thus, the resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. 

How can resistance of a circuit be decreased?

The resistance of a circuit can be decreased by increasing the cross-sectional area of the conductor, decreasing the length of the conductor, or by using a material with a lower resistivity.

What is resistivity?

Resistivity is a measure of a material’s ability to resist the flow of electric current. It is represented by the symbol ρ and is measured in ohm-meters (Ω·m).

What is relationship between resistance and power?

 The relationship between resistance and power is described by the formula 

 P = V²/R

P = I²R

Where 

• P is power, 
• V is voltage, and 
• I is current.

Electrical resistance is the obstruction offered by the material in the flowing of the current or charge through the material. Thus, the higher the resistance the lower the amount of current passing through it. It is the property of a material that tells us about the flow of the current through the material. The substances that easily conducts the electric current are called conductors and they have very low electrical resistance, on the contrary, the substance that does not easily conducts the electric current are called insulators and they have very high resistance.

In this article, we will learn about, electrical resistance, its formula, factors affecting electrical resistance, and others in detail.