What is Voltage?
Voltage, measured in volts (V), is the potential difference in electric potential energy between two points in a circuit. It's the "pressure" that drives electric current through a wire, allowing devices to operate. Think of voltage like the water pressure in a hose – the higher the pressure, the stronger the flow.
How Does Voltage Work?
Voltage is created by a difference in electric potential energy between two points. This difference can be generated by a battery, generator, or other power source. When a circuit is closed, the voltage pushes electric current through the wire, allowing devices to function.
In other words, voltage is the energy required to move a unit of electric charge from one point to another. It is measured in volts (V) and is calculated as the work done per unit charge (J/C).
Mathematical Definition:
- Voltage (V) = Work done (J) / Charge (C)
Example:
- A voltage of 9V means that 9 joules of energy are required to move 1 coulomb of charge from one point to another.
Types of Voltage
There are two main types of voltage:
Alternating Current (AC): Voltage that periodically reverses direction, commonly used in household power outlets.
Direct Current (DC): Voltage that flows in one direction only, commonly used in electronic devices and batteries
Importance of Voltage
Voltage plays a crucial role in electrical systems:
- Powering Devices: Voltage enables devices to function, from simple LED lights to complex computers.
- Energy Transmission: Voltage is used to transmit energy over long distances with minimal loss.
- Safety: Voltage determines the safety of electrical systems, with high voltages posing greater risks.
Voltage and how it relates to the electrical system
A basic circuit has three things, a power source, wires where you want the current path to go through and a load. The load is what you are trying to power, like a light, a heater, anything. The power source uses voltage to deliver electrical current in the circuit.
The circuit has a power source, in this case a battery. Then we have wires where the current flows through. Then we have the load, the load can be various things, even complex things. For example, it could be a tablet computer that is charging.
My favorite analogy;
A power source (like a DC battery or AC power connection from an electrical wall socket) can be thought of as a water faucet that delivers water at a certain water pressure. [Power = energy per unit time].
Wires of the circuit can be thought of as a water hose or water pipe. It is used to direct where you want the water to go through.
The load can be thought of as mechanical resistance, like pinching a part of the water hose to slow down the water flow.
Voltage, think of it as water pressure. An open water faucet with running water has water pressure pushing the water out of the faucet. [Voltage = electrical potential difference].
Whereas Current can be thought of as the amount of water that goes through a given point on the hose per unit time. For example, an open water faucet can fill an empty gallon container with water in one minute. The current would be one gallon per minute. [Current = electrical charge per unit time].
Important Laws and formulas for Voltage and electricity.
Ohms Law wikipedia
One of the first formulas one learns when it comes to electricity is Ohms Law:
- Current = Voltage / Resistance
The units for Current are amperes (A), units for voltage are volts (V) and the units for resistance are ohms (Ω). If you know any two you can calculate the other.
For example, if you know the voltage and the current, you can calculate the resistance:
(1) Resistance = Voltage / Current
Or, if you know the current and resistance, you can calculate the voltage.
(2) Voltage = Current x Resistance
Power wikipedia
To determine the power (the amount of energy consumed), use the following formula.
(3) Power = Voltage x Current
The units for power are Watts (W).
Using various equations of the previous Ohms Law, one can derive different ways to calculate power.
For example: you can use equation (3) and substitute it into equation (4) to get
(4) Power = Current^2 x Voltage
Or use equation (1) into equation (4) to get
Power = Voltage^2 / Resistance
So, now you know how to use voltage. Remember, it is easy to visualize by imagining it is water pressure with water flowing through a system of hoses and pipes with loads (resistances) being kinks in the hoses.
Real-World Applications
Voltage is essential in various industries:
- Electronics: Voltage powers devices like smartphones, laptops, and televisions.
- Power Generation: Voltage is used to transmit energy from power plants to households.
- Medical Equipment: Voltage powers life-saving devices like defibrillators and ventilators.
So to sum up our chat, Voltage is the backbone of electricity, enabling devices to function and power our daily lives. Understanding voltage is crucial for designing, building, and maintaining electrical systems. By recognizing the importance of voltage, we can harness its power to create innovative solutions and improve our world.