To read the magnetic strip on an ID or credit card, you must swipe it quickly past a tiny coil of wire. Why must the card be moving for the coil system to read it

#See solution for details

Explanation:

--The coil needs current for it to be able to read the strip.

-On a moving magnet or changing magnetic field will provide the electric field required to push induce the current needed.

-A moving magnet will induce a current in the coil so that the magnetic strip can be read.

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.