Look at the picture of an electromagnet that has picked up one sewing pin.
Which change could you make to allow the electromagnet to pick up more
sewing pins?
A. Use a nail that is much larger than the one shown.
B. Use a nail made of a nonmagnetic material.
C. Use half as many coils of wire around the nail.
OD. Use twice as many coils of wire around the nail.
