Electrical Engineering ⇒ Topic : Factors Upon Which Resistance Depends

Factors Upon Which Resistance Depends

The resistance R of a conductor

(1) is directly proportional to its length i.e.

(2) is inversely proportional to its area of X-section i. e

(3) depends upon the nature of material.

(4) depends upon temperature.

From the first three points (leaving temperature for the time being), we have

where p (Greek letter 'Rho') is a constant and is known as resistivity or specific resistance of the material. Its value depends upon the nature of the material.