What is Voltage?
Voltage, often referred to as electrical potential difference or electromotive force (EMF), is the force or 'pressure' that pushes electric current through a circuit. It quantifies the potential energy per unit of electric charge between two points in an electrical field, indicating how much work is required to move a unit charge between those points. The greater the voltage, the greater the potential to do electrical work.
How Voltage Works and Is Measured
Imagine voltage like water pressure in a pipe; higher pressure (voltage) forces more water (current) to flow. In an electrical circuit, a power source like a battery or generator creates this potential difference by establishing an imbalance of charge. This drives electrons from a point of higher potential energy to one of lower potential energy. Voltage is measured in volts (V) using a device called a voltmeter, typically placed in parallel across the two points being measured.
Voltage in Everyday Examples
Common devices utilize different voltage levels. A standard AA battery provides 1.5 volts, sufficient for small electronics like remote controls or toys. A car battery typically supplies 12 volts, essential for starting an engine and powering vehicle accessories. Wall outlets in homes deliver much higher voltages, usually 120V or 240V, to power appliances such as televisions, refrigerators, and computers, which require a stronger electrical 'push' to operate.
The Importance of Voltage in Circuits
Voltage is a fundamental characteristic of electricity, critical for the operation of all electronic devices. Without a sufficient voltage difference, there would be no 'push' to make current flow, and electrical components would remain dormant. It directly influences the amount of electrical power available and is a key factor in calculating energy consumption, designing safe electrical systems, and ensuring devices receive the correct power supply.