Question

There are two conductors X and Y carrying a current I and moving in the same direction. p and q are two electron beams also moving in the same direction. Will there be attraction or repulsion between the 2 conductors and between the two electron beams separately?

(a) The electron beams will repel each other and conductors attract each other

(b) The electron beams will attract each other and the conductors also attract each other

(c) The electron beams will attract each other and the conductors repel each other

(d) The electron beams will repel each other and the conductors also repel each other

The question was asked by my college director while I was bunking the class.

My question comes from Ampere and Forces between Two Parallel Currents topic in division Moving Charges and Magnetism of Physics – Class 12

Answer 1

The correct answer is (b) The electron beams will attract each other and the conductors also attract each other

The best I can explain: Since, both the current carrying conductors are moving in the same direction, they will attract each other. Moving electron beams is equivalent to an electric current in opposite direction. Therefore, there will attraction between the conductors X and Y as well as between the electron beams p and q.