PHYSICAL QUANTITY

Current strength: formulas and units of measurement

Current strength: symbol I, unit A. Formulas and explanations for Electricity.

I

\text{A}

ampere

KEY CONNECTIONS

Formulas

I = \frac{q}{t}

I = q / t

I = \frac{U}{R}

I = U / R

I = \frac{E}{R + r}

I = ε / (R + r)

I = q n v S

I = qnvS

j = \frac{I}{S}

j = I / S

m = k_{el} I t

m = kelIt

NOTATION

$I$: Current strength is the charge passing through the cross section of a conductor per unit time.
$q$: Electric charge is a quantity that determines the participation of a body in electrical interaction.
$t$: Time is a quantity characterizing the duration and sequence of events.
$U$: Electric voltage is the work done by the electric field when transferring a unit charge.
$R$: Electrical resistance is a measure of a conductor's resistance to electric current.
$\mathcal{E}$: Electromotive force is the work of external forces during the transfer of a unit charge.
$r$: Internal resistance is the resistance of the electric current source.
$n$: Concentration is the number of particles per unit volume.
$v$: Speed is the speed and direction of change in body position.
$S$: Area is the size of a surface or cross section.
$j$: Current density is the current strength per unit cross-sectional area.
$m$: Mass is a scalar physical quantity that is a measure of the inertia of a body.
$k_{\text{el}}$: Electrochemical equivalent is the mass of a substance released by a unit charge.

THEORY