potential difference

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potential difference

A student measures the potential difference across a battery with a voltmeter.

Definition

Noun: - The difference in electrical charge between two points in a circuit expressed in volts: This is the work needed per unit of charge to move a test charge between two points. It is the driving force that causes electric current to flow in a circuit.

Usage
  • Potential difference is a fundamental concept in electricity and electronics. It is measured using a voltmeter and is commonly called voltage.
  • It is a scalar quantity, meaning it has magnitude but no specific direction, though it is measured between two defined points.
  • It is the cause, while electric current is the effect.
Examples
  • Noun:
    • The battery provides a potential difference of 9 volts to the circuit.
    • To measure the potential difference across the resistor, connect the voltmeter in parallel with it.
    • A higher potential difference will push more current through a fixed resistor.
Advanced Usage
  • "Potential difference is maintained by...": Used to describe the source of the voltage.
    • In a cell, a chemical reaction maintains a constant potential difference between its terminals.
  • "A potential difference exists across...": Used to state where voltage is present.
    • A potential difference exists across the terminals of the power supply even when no current is flowing.
Variants and Related Words
  • Voltage (n): The common synonym for potential difference.
    • The voltage drop across the wire was negligible.
  • Electromotive force (EMF) (n): The specific potential difference generated by an energy source like a battery when no current is flowing.
  • Electric potential (n): The electrical potential energy per unit charge at a single point, relative to a reference point (often infinity or ground). Potential difference is the in electric potential between two points.
Synonyms
  • Voltage: The most common direct synonym.
  • Electric tension: A less common technical term.
Related Phrases
  • Potential drop: Often used interchangeably with potential difference, especially when referring to the voltage across a specific component like a resistor.
    • The potential drop across the lamp was 6 volts.
  • Terminal voltage: The potential difference across the terminals of a device (like a battery) when current is flowing.
Notes
  • Potential difference and voltage are used synonymously in most contexts. However, in precise physics, electromotive force (EMF) refers to the voltage generated by a source, while potential difference refers to the voltage measured between any two points, which may be less than the EMF due to internal resistance.
  • The standard unit is the volt (V).
potential difference

A student measures the potential difference across a battery with a voltmeter.

Noun
  1. the difference in electrical charge between two points in a circuit expressed in volts

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