PHYSICAL QUANTITY

Resistivity: formulas and units of measurement

Resistivity: symbol ρ, unit Ohm m. Formulas and explanations for Electricity.

\rho

\text{Om}\cdot\text{m}

ohm meter

KEY CONNECTIONS

Formulas

R = ρ \frac{l}{S}

R = ρl / S

ρ = ρ_{0} (1 + α t)

ρ = ρ₀(1 + αt)

1 Om \cdot m = 1 0^{6} \frac{Om \cdot mm ^{2}}{m}

1 Ohm m = 10⁶ Ohm mm²/m

NOTATION

$R$: Electrical resistance is a measure of a conductor's resistance to electric current.
$\rho$: Resistivity is a characteristic of a material’s ability to resist current.
$l$: Conductor length is the length of the conductor section under consideration.
$S$: Area is the size of a surface or cross section.
$\rho_0$: Initial resistivity is the resistivity at the initial temperature.
$\alpha$: Temperature coefficient is a characteristic of the change in resistance when heated.
$t$: Temperature is a measure of the thermal state of the body.

THEORY

PRACTICE