April 18, 2018
Test Your Knowledge Answer
Test Your Knowledge Question posted on Circuitnet on 4/17: Which scientific concepts is not symbolized by a capital letter: power, force, velocity, electric charge
Answer: Velocity is represented by the small letter 'v', power 'P", Force 'F', electric charge 'Q'
Your answer is incorrect.
Capital 'P' stands for Poise (viscosity unit), capital 'F' is the Faraday constant and also stands for Farad (electrical capacitance unit), while electric charge is most often represented by lowercase 'q'.
It appears there is a confusion at Circuitnet between quantity symbols and unit symbols.
Quantity symbols can be any letters as long as they do not coincide with unit symbols. For example, one cannot use V as symbol for voltage, because V is a unit symbol for Volt. The correct way would be U = 100 V, or Umax = 100 V, not Vmax etc.
Traditionally "v" is used for velocity, "f" is used for force (not capital F because that is a unit symbol for Farad), but that is not part SI standard, and the choice of quantity symbols is usually the writer's choice.
Reference: National Institute of Standards and Technology Special Publication 811, 2008 Edition. Guide for the Use of the International System of Units (SI).