Factors affecting the resistance
- Resistance R of a conductor is directly proportional to the length of the conductor
R ∝ l ⇢ (1)
- The resistance of a conductor is inversely proportional to the area of cross-section when the conductor is in a uniform shape.
R ∝ 1/A ⇢ (2)
- The resistance of a conductor also depends upon the nature of the conductor as well as the temperature of the conductor. So, by combining equations (1) and (2),
R ∝ l/A
R = ρl/A
ρ(rho) is constant which is called resistivity.
Check: Resistance Formula
Resistivity Formula
When a potential difference is applied across an object (conductor), the electrons start moving, which produces a current in the object. During this movement of electrons, they collide with other electrons too, which causes some opposition to the flow of electrons, this phenomenon of opposing the flow of electrons is known as Resistance(R). Its SI unit is the ohm(Ω)
Table of Content
- Factors affecting the resistance
- Resistivity Formula
- Derivation of resistivity
- SI unit of resistivity
- Factors affecting the resistivity
- Sample problems