Answer to Question #217294 in Mechanics | Relativity for Jacusi

Question

In which cases is there an attractive force?

A.   Two parallel beam of electrons with the same velocity

B.    Two parallel beam wires carrying current in opposite directions

C.    Two parallel beam of electrons in opposite directions

D.   A wire carrying current and a beam of parallel electrons in the same direction as the current.

E.    Wire carrying current and a beam of parallel electrons in opposite direction to the current.

Answer 1

 

Choice D: A wire carrying current and a beam of parallel electrons in the same direction as the current.

Two parallel electric conductors with both the current and electron moving in the same direction will be attracted to each other. The two conductors will produce magnetic fields with a corresponding force in the opposite direction.