---
categories:
  - Electronics
tags: [electricity, circuits]
---

# Circuits

An electrical circuit is a set of electrical components connected in such a way that current flows in a loop from a voltage source, through the circuit elements and back to the voltage source.

Below is a basic circuit representing a 9-volt [battery](/Electronics_and_Hardware/Analogue_circuits/Cells_and_batteries.md#cells-and-batteries) with a 10,000$\Omega$ [resistor](/Electronics_and_Hardware/Analogue_circuits/Resistance.md) attached accross its terminals. Through the application of [Ohm's Law](/Electronics_and_Hardware/Physics_of_electricity/Ohms_Law.md) we can determine that the maximum current will be 0.9 miliamps.

![](/_img/basic-circuit.png)

## Open and short circuits

A circuit with a break in its loop is called an **open circuit**. When a circuit is open, no current flows. We can induce an open circuit through the use of a switch component that closes and breaks the circuit when invoked.

A **short circuit** is a path in a circuit that allows current to flow with little or no resistance. This is usually unintentional and results in excessive current flowing through the circuit. A short circuit is the opposite to an open circuit. With an open circuit there is an infinite resistance between the two terminals.

## Vertical circuit diagrams

Sometimes circuits can be represented in a vertical manner rather than in an actual circuit. This is done to simplify the representation. In this approach current is represented as flowing in a straight line from the voltage source (represented with a circle) to ground.

The circuit below is functionally identical to the previous circuit but represented vertically:

![](/_img/vertical-circuit.png)
