Magnetic fields and stuff gets interesting when Einstein gets envolved. RELATIVITY

Body

https://www.physics-and-radio-electronics.com/electronic-devices-and-circuits/semiconductor/intrinsic-semiconductor/electron-and-hole-current.html

https://www.allaboutcircuits.com/textbook/semiconductors/chpt-2/electrons-and-holes/

https://www.quora.com/How-does-one-explain-electricity-at-relativistic-speeds 
This is absolutely a great dissertation on my main interest in NEGATIVE 
ELECTRICITY.

See 33432 at attachments    Remember my paper on WHAT is HEAT, negative 
Ions = cold, positive Ions = hot.

See InTech at attachments

https://physics.stackexchange.com/questions/71099/relativity-and-current-in-wire

https://www.khanacademy.org/science/electrical-engineering/introduction-to-ee/intro-to-ee/v/ee-conventional-current

https://www.khanacademy.org/science/electrical-engineering/introduction-to-ee/intro-to-ee/v/current-direction

https://www.khanacademy.org/science/physics/magnetic-forces-and-magnetic-fields/magnetic-field-current-carrying-wire/v/magnetism-6-magnetic-field-due-to-current

Warren, You are an Old Navy Salt, Sailor, whom will appreciate the color 
coding of conductors by the Marine Industry, taken from the U.S. Navy 
days gone by.   When I went through DeVry School in 1953, I learned that 
Black was common ground in a circuit and white

was the hot wire. U.S. Navy.  Remember when General motors used a 
POSITIVE ground on their cars and Ford had a NEGATIVE ground as did the 
U.S. Navy to prevent the electroylisis problem.  We had to be careful 
when using battery cables trying to jump start a Chevy from a Ford 
battery, cause of opposite polarity.  Gee.  The salt used on the roads 
up North ate up the fenders of Chevys. Lol