PHYSICAL QUANTITY

Electrical resistance: formulas and units of measurement

Electrical resistance: symbol R, unit Ohm. Formulas and explanations for Electricity, Oscillations and waves.

Rohm

KEY CONNECTIONS

Formulas

R = U / I

R = ρl / S

Xᴸ = 2πνL

Xᶜ = 1 / (2πνC)

R = R₀(1 + αt)

NOTATION

: Electrical resistance is a measure of a conductor's resistance to electric current.
: Electric voltage is the work done by the electric field when transferring a unit charge.
: Current strength is the charge passing through the cross section of a conductor per unit time.
: Resistivity is a characteristic of a material’s ability to resist current.
: Conductor length is the length of the conductor section under consideration.
: Area is the size of a surface or cross section.
: Inductive reactance is the resistance of the coil to alternating current.
: Frequency is the number of repetitions of a process per unit of time.
: Inductance is the ability of a conductor to create a magnetic field when current passes.
: Capacitance is the resistance of a capacitor to alternating current.
: Electrical capacity is the ability of a conductor or capacitor to accumulate charge.
: Initial resistance - resistance at the selected initial temperature.
: Temperature coefficient is a characteristic of the change in resistance when heated.
: Temperature is a measure of the thermal state of the body.

THEORY

PRACTICE

Topics in order: the concepts, quantities and formulas of a lesson with explanations and examples.

Statements, answer options and a detailed walkthrough for every topic of the course.

A 10-question check-up, exercises with answer checking, and saved progress.