# Define Resistance ? What Are The Factors Which Effect Resistance ?

Resistance is the property Of material by which it opposes (or resists) the flow of current is known as resistance.

## What Is Resistance

The property Of material by which it opposes (or resists) the flow of current is known as resistance.

### Symbol Of Resistance

The practical unit of resistance is ohm and is denoted by ohm: Ω

### Laws Of Resistance

The resistance offered by a conductor depend on following factors

• (1) It is directly proportional to its length i.e. R L
• (2) It is inversely proportional to the area of cross section of the conductor, i.e. R L/A
• (3) It depend on the temperature of conductor.
• (4) It also depends on the nature of material of conductor.

Neglecting temperature and nature of conductor,resistance of conductor is directly proportional to its length and inversely proportional to area of cross section.

where “rho” is a proportionality constant and known as resistivity or specific resistance of conductor.

hence unit of resistivity is

(i.e. ohm-meter)

Resistance offered by 1 m length or conductor having cross sectional area of 1 m2 is called specific resistance of 1 ohm-m .

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