PHYSICAL QUANTITY

Electromotive force: formulas and units of measurement

Electromotive force: symbol ε, unit B. Formulas and explanations for Electricity, Magnetism.

\mathcal{E}

\text{V}

volt

KEY CONNECTIONS

Formulas

E = \frac{A _{st}}{q}

ε = Ast / q

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

I = ε / (R + r)

E_{i} = n \frac{∣ ΔΦ ∣}{Δ t}

εᵢ = n|ΔΦ| / Δt

E_{si} = L \frac{∣ Δ I ∣}{Δ t}

εsi = L|ΔI| /Δt

NOTATION

$\mathcal{E}$: Electromotive force is the work of external forces during the transfer of a unit charge.
$A_{\text{st}}$: The work of external forces is the energy transferred to the charge by non-electrostatic forces.
$q$: Electric charge is a quantity that determines the participation of a body in electrical interaction.
$I$: Current strength is the charge passing through the cross section of a conductor per unit time.
$R$: Electrical resistance is a measure of a conductor's resistance to electric current.
$r$: Internal resistance is the resistance of the electric current source.
$\mathcal{E}_i$: The electromotive force of induction is the action of a vortex electric field in a circuit.
$n$: The number of turns is the number of turns of conductor in the coil.
$\Delta\Phi$: Magnetic flux change is the amount of change in magnetic field flux.
$\Delta t$: Time interval - the duration of the process under consideration.
$\mathcal{E}_{\text{si}}$: The electromotive force of self-induction is the action of the field that arises when one's own current changes.
$L$: Inductance is the ability of a conductor to create a magnetic field when current passes.
$\Delta I$: Change in current strength - the amount of change in current over the time in question.

THEORY

PRACTICE