11. List two methods of producing magnetic fields.

1. By using a permanent magnet we can produce the magnetic field and it can be visualized by spreading iron fillings on a white paper and keeping a magnet beneath the paper.

2. A current-carrying straight conductor produces the magnetic field.

it's not c. i took the quiz and got it wrong. so my best guess is b.

have a great day, and hope this .

a=c and then d= c because of the band so you get ac/dc and you add them together you get sound waves