an electrical current through a copper wire A) creates a magnetic field around the wire B) creates magnetic poles in the wireC) magnetizes the wireD) does not create a magnetic field
Answer is A Explaination: If you pass current through a straight wire, magnetic field is formed around the wire in the form of circular rings (could affect compass or metal fillings nearby). On the other hand, you're passing current through a circular spring-like thing (commonly, a coil) called solenoid, magnetic field is produced along its axis. Simply you could keep in mind that Magnetic field is produced by moving charges (current). This is an observed phenomena and it's explained by Maxwell.