Which symbol is used to represent voltage?

Which symbol is used to represent voltage?

• A. V
• B. I
• C. E
• D. U

Answer: (C)

Voltage is the electric potential difference between two points in a circuit, and the symbol most commonly used to denote it is V. This symbol comes from the unit volt, named after Alessandro Volta. While you might see other symbols in specific contexts—E for electromotive force (the ideal potential a source can provide, often before accounting for internal resistance) and U in some European texts for voltage—the standard in most HVAC and circuit diagrams is V. Using V helps keep equations consistent, for example in Ohm’s law where the voltage across a component is V = I × R. When a source has internal resistance, its emf is E, but the actual voltage you measure across the terminals under load is still represented as V in typical analysis.

Voltage is the electric potential difference between two points in a circuit, and the symbol most commonly used to denote it is V. This symbol comes from the unit volt, named after Alessandro Volta. While you might see other symbols in specific contexts—E for electromotive force (the ideal potential a source can provide, often before accounting for internal resistance) and U in some European texts for voltage—the standard in most HVAC and circuit diagrams is V. Using V helps keep equations consistent, for example in Ohm’s law where the voltage across a component is V = I × R. When a source has internal resistance, its emf is E, but the actual voltage you measure across the terminals under load is still represented as V in typical analysis.