(Solved): PHYSICS: PHET Magnetism (USE simulation google PHET magnets and electromagnets) Notice that t ...

PHYSICS: PHET Magnetism (USE simulation google “PHET magnets and electromagnets”)

Notice that the moving blue dots in the wire are moving electrons.  Use the voltage slider (in the batter) to make the battery voltage 0 V.  
a.    What happens to the motion of the electrons when the voltage is zero?
b.    Is there a magnetic field around a system without moving electrons? 
?.    Explain why an electromagnet produces a magnetic field?