Q: Is a volt defined as the difference in electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points? ¶
Q: Was a volt defined as the potential difference [i.e.? ¶
A: Yes, and what is nowadays called the "voltage "] across a conductor when a current of one ampere dissipates one watt of power.
Q: Was a volt maintained in national laboratories using specially constructed batteries called "standard cells"? ¶
A: Yes, The United States used a design called the Weston cell from 1905 to 1972.