Which of the following would cause an iron bar to start generating a magnetic field? A Orienting the iron bar so that it points to the North pole. B Labeling the ends of the bar with "N" and "S".
C Melting the bar completely and letting it cool down slowly.
B Wrapping the bar with a coil of wire that has an electric current.

Wrapping the bar with a coil of wire that has an electric current.

Explanation:

To cause an iron bar to start generating a magnetic field, wrap the bar with a coil that has an electric current.

Wrapping the bar with a coil of wire that has electric current can cause an iron bar to start producing magnetic fields. This way, the iron bar becomes a magnet.

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