Voltage and current are two fundamental concepts in electrical engineering, and understanding the difference between them is crucial to developing a deeper understanding of how electricity works. In this technical blog, we’ll explore the key differences between voltage and current, including their definitions, units of measurement, and practical applications.

### What is Voltage?

Voltage, also known as electric potential difference, is the measure of the electric potential energy per unit charge. In simpler terms, voltage is the force that drives electrons to flow through a circuit. It is the potential difference between two points in a circuit, which allows for the transfer of energy from one point to another. Voltage is measured in volts (V), which is defined as one joule of energy per coulomb of charge.

Voltage can be compared to the pressure in a water pipe. Just as water flows from an area of high pressure to an area of low pressure, electrical current flows from a point of higher voltage to a point of lower voltage. A higher voltage difference means that there is more energy available to drive current through a circuit.

### What is Current?

Current is the flow of electric charge through a circuit. It is measured in amperes (A), which is defined as the amount of charge that passes through a point in a circuit per second. The flow of current in a circuit is due to the movement of electrons, which are negatively charged particles. Electrons flow from the negative terminal of a voltage source to the positive terminal, completing a circuit and allowing for the transfer of energy.

Current can be compared to the flow rate of water in a pipe. Just as the flow rate of water is measured in gallons per minute, the flow of electrical current is measured in amperes. The rate at which current flows through a circuit depends on the voltage applied and the resistance of the circuit. A higher voltage or lower resistance will result in a greater flow of current.

### Key Differences between Voltage and Current

While voltage and current are closely related, there are several key differences between them:

- Definition: Voltage is the measure of electric potential energy per unit charge, while current is the flow of electric charge through a circuit.
- Units: Voltage is measured in volts, while current is measured in amperes.
- Symbol: Voltage is typically represented by the symbol “V”, while current is represented by the symbol “I”.
- Effect on the Circuit: Voltage is the force that drives current through a circuit, while current is the actual flow of electrons.
- Dependency: Voltage is independent of the circuit, while current is dependent on the circuit’s resistance.

### Applications of Voltage and Current

Understanding voltage and current is essential for many applications in electrical engineering. Some common applications of voltage and current include:

- Power Supplies: Voltage is used to power electronic devices, such as smartphones, laptops, and televisions.
- Electric Motors: Current is used to power electric motors, which convert electrical energy into mechanical energy.
- Circuit Analysis: Voltage and current are both essential for analyzing and designing electrical circuits.
- Electrical Safety: Understanding voltage and current is important for electrical safety, as exposure to high voltages or currents can be dangerous or even fatal.

### Conclusion

In summary, voltage and current are two fundamental concepts in electrical engineering. Voltage is the measure of electric potential energy per unit charge, while current is the flow of electric charge through a circuit. Understanding the differences between these two concepts is essential for designing and analyzing electrical circuits, powering electronic devices, and ensuring electrical safety.

### Written by: Cole Attaway

Cole Attaway is the founder and CEO of Spike Electric Controls. Spike's mission is to improve the accessibility and delivery of industrial electrical gear for clients nationwide. Spike solutions result in reduced unplanned downtime, less overtime, and greater operational efficiencies.