# Types of electric current in a circuit

Physics > Different types of current

Find out which ones are types of currents in electrical circuits: types of electric current, direct current circuit diagram, Ohm’s law, direct current circuit.

Electrical circuit – contact of electrical components in a closed loop.

## Learning challenge

• Characterize the structure of the electrical circuit and identify the elements of the DC circuit.

## Key points

• Direct current – directed in one direction of the flow of electric charge.
• Direct current is generated by sources such as batteries, thermocouples, solar cells, and electrical machinery.
• A constant current circuit consists of constant current and voltage sources and resistors.
• The circuit diagram is powered by direct current, although DC voltage is often written to the sources.
• To electrical networks apply: Ohm’s law, Kirchhoff’s laws of current and voltage, Theven and Norton’s theorems. They help determine the electrical potential and current at any point.

## Terms

• Electrical circuit – communication between electrical elements (inductors, resistor, capacitors, transmission lines, voltage sources, etc.).
• The current-voltage characteristic is the relationship between the electrical circuit and the corresponding voltage.
• An electric current is called constant, where electrons move in one direction, but can change over time.

## Overview

An electrical network is a collection of electrical elements. An electrical circuit diagram conveys a particular type of network with a closed loop allowing current to travel in the opposite direction. If the electrical network is represented only by sources of linear elements, then it can be considered by the methods of algebraic transformation.

A resistor circuit only accommodates resistors and ideal current and voltage sources. Its analysis is inferior in complexity, since it does not have inductors and capacitors. If the sources are constant, then we are faced with a direct current circuit. A network with active electronic components is an electronic circuit. It is usually non-linear and requires more sophisticated design tools.

## Direct current circuits

Direct current is an electric charge directed in one direction. It is formed from various sources such as solar cells, batteries, electric cars. Forward current is capable of traveling through semiconductors, insulators, and even vacuum. The charge flows in a constant direction, which is what differs from alternating current.

A DC circuit displays an electrical circuit with any combination of constant voltage and current sources and resistors that are not time dependent. That is, the system of equations transmitting the DC circuit will not take into account integrals or derivatives of time. If you add a capacitor or inductor to a DC circuit, then it will no longer be a specific type of circuit. However, most of these circuits are solved as direct current and displayed by differential equations.

In solving such equations of a DC circuit, transition parts or elements that change over time, as well as a stable part, flicker. It is the latter that acts as a solution for direct current. In electronics, reference is made to a circuit that is powered by a stable voltage source.

A simple diagram is shown in the figure. Electrical components are represented by characteristic symbols. Please keep in mind that the notation may differ depending on the selected textbook. A simple DC circuit with a voltage source (V) and resistor (R). The current passing through the circuit is calculated by Ohm’s law

## Physical laws

All electrical circuits obey a number of laws: Ohm’s, Kirchhoff’s law of current and voltage, Theven and Norton’s theorems (great for complex circuits).

### Physics Section

Overview
• Different types of current
• Sources of EMF
Parallel and series connection of resistors
• Series connection of resistors
• Parallel connection of resistors
• Combined schemes
• Battery charging: EMF in serial and parallel connections
• EMF and of course voltage
Kirchhoff rules
• Introduction and meaning
• Join rule
• Stress rule
• Application
Voltmeters and ammeters
• Voltmeters and ammeters
• Zero measurements
RC circuits
• Resistors and capacitors in series communication
• Impedance
• Phase angle and power factor