Question

What is the force on a current-carrying wire that is parallel to a magnetic field? Give reason for your answer. 

Answer 1

The force on a current-carrying wire parallel to the magnetic field is zero because the magnetic force on the wire is due to the force experienced by moving electrons in the conductor. Further, the magnetic force has rotatory effect on electron motion only. Therefore, in parallel condition, this rotating effect is zero and this results in zero force on the conductor.