The inventor of the first thermionic valve made what visual mnemonic tool for generators?
Fleming's left-hand rule for motors: Fleming's left-hand rule for motors is one of a pair of visual mnemonics, the other being Fleming's right-hand rule (for generators). John Ambrose Fleming: Sir John Ambrose Fleming FRS (29 November 1849 – 18 April 1945) was a British electrical engineer and physicist. John Ambrose Fleming:  He is known for inventing the first thermionic valve or vacuum tube.
i don't know