Potential difference, in the context of electricity and electric fields, refers to the measure of the electrical potential energy per unit charge between two points in an electric circuit or field. It is commonly denoted by the symbol VVV and measured in volts (V).
In simple terms, potential difference describes how much energy is needed to move a unit of electric charge from one point to another. Electrically, this difference is what causes charges to flow through a conductor when a circuit is completed. When a voltage source (such as a battery or power supply) is connected to a circuit, it establishes a potential difference between its terminals. Electrons then flow from the negative terminal (lower potential) to the positive terminal (higher potential) through the circuit, powering devices connected to it.
Electric potential difference is also closely related to the concept of electric potential, which is the amount of work needed to move a unit positive charge from a reference point (usually infinity) to a specific point in an electric field. The potential difference between two points is equal to the change in electric potential energy per unit charge between those points.
In Class 10 science notes, potential difference is typically introduced as the voltage difference between two points in an electrical circuit. It is fundamental to understanding how electricity flows and is used to power devices in everyday applications. For mains electricity, the potential difference refers to the voltage supplied by the utility grid to homes and businesses, typically around 110-120 volts (in North America) or 220-240 volts (in many other parts of the world), alternating at a frequency of 50 or 60 Hz.
In summary, potential difference is a crucial concept in electricity, describing the driving force that causes electric charges to move through conductors and power electrical devices. It plays a central role in both understanding basic electrical principles and practical applications in electrical engineering and technology.