What Is Voltage? GA S REGULAR Menu Lifewire Tech for Humans Newsletter! Search Close GO Home Theater & Entertainment > TV & Displays 50 50 people found this article helpful
What Is Voltage? (Definition)
The electromotive force between two points, per unit of charge
By Gary Altunian Gary Altunian Writer Gary Altunian was a freelance contributor to Lifewire and industry veteran in consumer electronics. He passion was home audio and theater systems. lifewire's editorial guidelines Updated on September 3, 2021 Tweet Share Email Tweet Share Email TV & Displays HDMI & Connections Samsung Projectors Antennas Remote Controls Voltage is the electromotive force or the electric potential energy difference between two points (often within the context of an electrical circuit) per unit of charge, expressed in volts (V). Voltage, along with current and resistance, describes the behavior of electrons. The relationships are observed through the application of Ohms law and Kirchhoff's circuit laws. Public Domain via Wikimedia Commons Voltage An Example of the Concept
The concepts of voltage, charge, current, and resistance can be explained with a bucket of water and a hose attached to the bottom. The water represents charge (and the movement of electrons). The flow of water through the hose represents current. The width of the hose represents resistance; a skinny hose would have less flow than a wider hose. The amount of pressure created at the end of the hose by the water represents voltage. If you were to pour one gallon of water into the bucket while covering the end of the hose with your thumb, the pressure you feel against the thumb is similar to how voltage works. The potential energy difference between the two points — the top of the water line and the end of the hose — is just that one gallon of water. Now let's say that you found a bucket large enough to be filled with 450 gallons of water (roughly enough to fill a six-person hot tub). Imagine the kind of pressure your thumb might feel while attempting to hold that quantity of water back. Putting It All Together
Voltage (the cause) is what makes the current (the effect) happen; without any voltage push to force it, there would be no flow of electrons. The amount of electron flow created by voltage is important with respect to the work that needs to be done. A few 1.5 V AA batteries are all you need to power a small remote-controlled toy. But you wouldn't expect those same batteries to be able to run a major appliance requiring 120 V, such as a refrigerator or clothes dryer. Consider the voltage specifications with electronics, particularly when comparing protection ratings on surge protectors. The United States electrical grid, for example, operates at 120 V (at 60 Hz), which means you can use a 120 V stereo receiver with a pair of speakers. But in order for that same stereo receiver to work safely in Australia, which operates at 240 V (at 50 Hz), you need a power converter and plug adapter. FAQ What is the definition of high voltage? The International Electrotechnical Commission (IEC) defines high voltage as more than 1,000 volts (V) of alternating current (AC) and above 1,500 V of direct current (DC). However, the Occupational Safety and Health Administration (OSHA) considers all voltages of 50 volts or above hazardous. What is the definition of a voltage drop? A voltage drop is voltage loss due to impedance. Excessive voltage drop can cause improper, erratic, or no operation of electrical equipment. You can help prevent voltage drops using a voltage regulator. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit More from Lifewire Can a 12 Volt Car Battery Really Electrocute Someone? A Simple Explanation of Alternator Output Ratings What Are Diodes and What Are They Used For? 15-Pin SATA Power Connector Pinout Level 1 vs. Level 2 vs. Level 3 Charging Explained Picking a UPS (Battery Backup) for Your Mac or PC What Does an EV Battery’s Miles per KWh Number Mean? What Is a Trickle Charger? How to Fix a Broken Charger Westinghouse iGen2500 Generator Review: A Lightweight, Efficient Portable Generator What Are the Applications of Capacitors? What Is Bandwidth? Definition, Meaning, and Details How ‘Green’ are Electric Vehicles, Really? Condenser Microphones vs. Dynamic Microphones The 8 Best Portable Generators of 2022 The 6 Best Power Inverters of 2022 Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies