# Direct-Current Circuit Basics

## Schematic Symbols

The simplest schematic symbol is the one representing a wire or electrical conductor: a straight, […]

## Schematic and Wiring Diagrams

In a schematic diagram, the interconnection of the components is shown, but the actual values […]

## Voltage,Current,Resistance,Circuits

Most dc circuits can be boiled down to three major components: a voltage source, a […]

## Ohm’s Law

The interdependence among current, voltage, and resistance in dc circuits is called Ohm’s Law, named […]

## Current Calculations

The first way to use Ohm’s Law is to determine current in dc circuits. In […]

## Voltage Calculations

The second application of Ohm’s Law is to find unknown dc voltages when the current […]

## Resistance Calculations

Ohms’ Law can be used to find a resistance between two points in a dc […]

## Power Calculations

A circuit for working Ohm’s Law problems You can calculate the power P, in watts, […]

## Resistances in Series

When you place resistances in series, their ohmic values add together to get the total […]

## Resistances in Parallel

When resistances are placed in parallel, they behave differently than they do in series. One […]

## Division of Power

When combinations of resistances are connected to a source of voltage, they draw current. You […]

## Resistances in Series-Parallel

Sets of resistors, all having identical ohmic values, can be connected together in parallel sets […]