[MarcScott]

I fondly remember watching kids in physics exams trying to answer questions using Felming's left hand rule. (https://en.wikipedia.org/wiki/Fleming's_left-hand_rule_for_m...

You could watch them hold up both hands, wondering which one to use, then trying to dislocate their wrists as they aligned fingers and thumb with the diagram on the exam paper.

[dboreham]

Always use Maxwell's corkscrew rule.