Voltage is a physical quantity in the field of physics, specifically in the area of electromagnetism and electricity. It is the electric potential energy per unit charge, measured in joules per coulomb (= volts)

. The term "voltage" is derived from the name of Italian physicist Alessandro Volta, who invented the voltaic pile, the forerunner of today's household battery

. Voltage can be understood as the pressure from an electrical circuit's power source that pushes charged electrons (current) through a conducting loop, enabling them to do work, such as illuminating a light

. In an electrical circuit, voltage is the difference in electric potential between two points

. It can be caused by the build-up of electric charge (e.g., a capacitor), an electromotive force (e.g., electromagnetic induction in a generator), or other electrochemical processes (e.g., cells and batteries)

. Some key points about voltage include:

• Voltage is a scalar quantity, meaning it has only magnitude and no direction

• It is the difference in electric potential between two points in a circuit

• Voltage can be either alternating current (ac) or direct current (dc)

• The SI unit of voltage is the volt (V)

Voltage is a crucial concept in understanding how electrical circuits function and is essential for calculating the work done by an electric current in various applications, such as lighting or powering electronic devices