Voltage, also known as electric potential difference, is the measure of the force or push that drives electric charge through a conductor in an electrical circuit. It is often expressed in volts.
It represents the force that drives electric current. The formula for electric potential (V), or voltage, is given by Ohm’s Law as:
V=I⋅R
- V represents voltage, measured in volts (V).
- I represents current, measured in amperes (A).
- R represents resistance, measured in ohms (Ω).
Imagine a water tank on a hill; the height difference between the top and bottom corresponds to voltage. Water at the top has potential energy, and as it flows down, this potential is converted into kinetic energy. Similarly, in an electrical circuit, voltage is the energy per unit charge, analogous to the height of the water tank. When a circuit is connected, electrons flow from high to low voltage, similar to water moving downhill. Higher voltage signifies more potential energy for electrons to do work, such as lighting a bulb or powering a device.
Daily Life Examples of Voltage
- Plugging your phone into a charger creates a voltage difference, allowing the electric charge to flow into the battery.
- When you flip the switch, the voltage in the circuit enables the flow of electricity, lighting up the bulb.
- The voltage provided to a blender powers its motor, allowing it to blend your smoothie ingredients.
- The power adapter supplies the laptop with the necessary voltage for it to function and charge.
- Electric cars rely on voltage from the battery to power the electric motor and drive the vehicle.
Mathematical Relations of Voltage
- Ohm’s Law: V=I⋅R
- Voltage (V) is equal to the product of current (I) and resistance (R).
- Power Formula: P=V⋅I
- Power (P) is equal to the product of voltage (V) and current (I).
Commonly Used Units of Voltage:
| Unit | Symbol | Equivalent in Volts |
|---|---|---|
| Volt | V | 1 V |
| Kilovolt | kV | 1,000 V |
| Megavolt | MV | 1,000,000 V |
Simple Case Study: Understanding Voltage in a Circuit
Imagine a simple circuit with a light bulb and a battery. The battery generates a voltage difference across its terminals. This voltage creates an electric field that pushes charged particles, allowing current to flow. When you close the circuit by flipping the switch, the voltage drives the electric charge, causing the light bulb to illuminate. This case illustrates how voltage is essential for the flow of electricity in a circuit.
Summary Points:
- Voltage is the force that drives electric charge in a circuit.
- Measured in volts (V).
- Examples in daily life include charging devices, lighting bulbs, and powering appliances.
- Common units include volts, kilovolts, and megavolts.
- Ohm’s Law and the power formula describe the relationship between voltage, current, and resistance.
- Voltage is like the pressure in a water pipe, pushing electric charges through a circuit.
