What Is Potential Difference In Simple Words?

Definition of Potential Difference

Potential difference, also known as voltage, is the difference in electric potential energy between two points in an electric field. It measures the “push” or “pressure” of an electric field that causes electricity to flow.

In simple terms, potential difference is what makes electricity move through a circuit. Electricity flows from a point of high potential energy to a point of low potential energy. So there needs to be a difference in energy levels for current to flow.

For example, when you connect the positive and negative terminal of a battery, there is a potential difference that makes electrons move from the negative to the positive side. The greater the difference, the stronger the push and the higher the voltage.


Voltage is the measure of potential difference between two points in an electrical circuit. It refers to the “push” or “pressure” that causes current to flow through a circuit. Voltage is sometimes referred to as electromotive force (emf).

When there is a difference in electric potential between two points, it gives the electrons potential energy and a “push” to flow from areas of higher potential to lower potential. The greater the difference in potential, the greater the voltage and the stronger the push on the electrons.

Voltage is measured in volts and represents the energy gained or lost by electrons as they move through a circuit. A 9V battery, for example, indicates a 9 volt difference in potential energy from the negative to positive terminal of the battery.

Electric Field

An electric field is produced by electric charges. The electric charges in atoms and molecules cause them to generate electric fields. When positive and negative charges are separated from each other, they create a voltage between them. This voltage leads to an electric field that extends through the space between the charges. The more separated the charges are, the stronger the electric field.

electric field between positive and negative charges

The electric field causes positive charges to move in the direction of negative charges. It gives a force to any charged particles inside the field, causing current to flow if the charges are free to move. This force from the electric field creates a potential difference between the positive and negative charges. The greater the electric field strength, the greater the force on the charges, which leads to a larger potential difference.

For example, in a battery the chemical reactions separate positive and negative charges onto the two terminals. This creates an electric field within the battery that causes a potential difference between the terminals. The larger the separation of charges, the bigger the resulting potential difference. Devices connected to the battery use this potential difference to generate current flow.


A battery is a device that converts chemical energy into electrical energy. Inside a battery, chemical reactions produce positive and negative charges that accumulate on the battery’s terminals. This separation of charge creates an electric field and a difference in electric potential (voltage) between the terminals.

The positively charged terminal is called the cathode and the negatively charged terminal is called the anode. When the battery is hooked up in a circuit, the potential difference causes electrons to flow from the anode (negative terminal) to the cathode (positive terminal) through the circuit, producing an electric current.

The larger the potential difference, the greater the force pushing the electrons through the circuit. Alkaline batteries like AA and AAA batteries provide 1.5 volts. Lithium ion batteries in cell phones and laptops may provide between 3.6 to 3.7 volts.

So in summary, a battery acts as a source of potential difference or voltage that then drives an electric current through a closed circuit.

Current Flow

Potential difference is what causes current to flow in a circuit. Current is the flow of electric charge carriers like electrons through a material. Materials like metals have free electrons that can move about, whereas insulators don’t have free electrons that can flow.

When there is a potential difference applied across a conductive material like a wire, it gives the electrons energy, creating an electric field that exerts force on them. This electric field pushes the electrons through the wire, creating a flow of electric current.

So in essence, potential difference provides the driving force for electric current. The greater the potential difference, the stronger the electric field, and the greater the flow of current. This is why devices with higher voltage ratings require more potential difference to operate.

Electromotive Force

Potential difference is also referred to as electromotive force (EMF). EMF is the energy per unit charge provided by a source of electrical energy such as a battery or generator. It is measured in volts. EMF pushes electric charge around an electric circuit and provides the energy needed to move electrons through a conducting path.

For example, a 12V car battery provides 12 volts of electromotive force which pushes current through the wires and components of the car electrical system. The greater the EMF, the greater the force pushing the electrons. EMF is an important concept for understanding how voltage sources like batteries and generators work in electrical circuits.

Electrical Energy

Potential difference is closely related to the concept of electrical energy. Energy is defined as the capacity to do work. In electrical circuits, the energy carried by the electrons enables them to do work like powering devices and appliances.

Potential difference represents the amount of energy each electron gains or loses as it moves through the circuit. It is measured in units of joules per coulomb, which is equivalent to volts. A higher potential difference means the electrons have more energy to give up.

For example, a 9V battery provides 9 joules of energy for each coulomb of charge that passes through it. This energy is converted into useful work like light, heat, or motion by the devices connected to the battery.

So in summary, potential difference is the energy gained or lost per unit charge as electrons flow through a circuit. It powers the work done by electrical devices and appliances in our everyday lives.

Simple Analogy for Potential Difference

A simple analogy that can help explain potential difference is water flowing through a pipe. Imagine connecting two water tanks at different heights with a pipe. Water will flow from the higher tank to the lower tank. The higher tank has higher potential energy, while the lower tank has lower potential energy. The difference in water levels between the tanks creates a potential difference. Just like the difference in voltage between two points in a circuit causes electrons to flow.

Another analogy is rolling a ball down a hill. A ball at the top of a hill has higher potential energy than at the bottom. When released, gravity will accelerate the ball downhill, converting that potential energy into kinetic energy. Similarly, electrons flow “downhill” from high to low potential in a circuit, gaining kinetic energy that manifests as current.

Using analogy and real-world examples can make the abstract concept of potential difference more intuitive and easier to grasp.


Potential difference has many useful applications in our everyday lives. Here are a few examples:

Batteries and power sources – Batteries provide a potential difference that allows electric current to flow through an external circuit. This electric current can then power various devices and appliances. The higher the potential difference of a battery, the greater the power it can provide.

Electrical wiring and transmission – Potential difference drives electrons through wires and cables, allowing electricity transmission over long distances. High voltage wires are used to minimize power losses during transmission.

Sensors – Many sensors work by detecting a change in potential difference. This includes pressure, temperature, and motion sensors. The sensor outputs a voltage signal proportional to the physical quantity being measured.

Semiconductors and electronics – Semiconductor devices like diodes and transistors rely on potential difference to control electron flow and serve as electrical switches. Integrated circuits use potential differences for digital logic and signal processing.

Electrolysis – Applying a potential difference across two electrodes immersed in an electrolyte drives oxidation and reduction reactions. This is used for electroplating and metal refining.

Summary: Potential Difference in Simple Words

Potential difference, or voltage, is the difference in electric potential energy between two points in an electric field. It can be thought of as electric pressure that causes current to flow. Key points:

  • Voltage measures the work required to move electric charges between two points.
  • Higher voltage = greater electric force.
  • Voltage is created by electric energy sources like batteries.
  • Voltage drives the motion of charges in circuits.
  • More voltage enables more current flow.
  • Voltage has many practical applications in electrical devices and systems.

In simple terms, voltage is the electric energy “push” that powers electronics and appliances in our everyday lives.

Similar Posts