Fleming's rules

plural noun

1. physics two rules used as mnemonics for the relationship between the directions of current flow, motion, and magnetic field in electromagnetic induction. The hand is held with the thumb, first, and second fingers at right angles, respectively indicating the directions of motion, field, and electric current. The left hand is used for electric motors and the right hand for dynamos

Word History and Origins

Origin of Fleming's rules¹

C19: named after Sir John Ambrose Fleming , who devised them