(a) How can you produce a magnetic field that is nearly uniform in a region? (b) How can you produce a magnetic field that falls off like 1/r? (c) How can you produce a magnetic field that falls off...

(a) How can you produce a magnetic field that is nearly uniform in a region?

(b) How can you produce a magnetic field that falls off like 1/r?

(c) How can you produce a magnetic field that falls off like 1/r2? (Note that you cannot use just a short piece of

current-carrying wire, because the other parts of the wire also contribute.)

(d) How can you produce a magnetic field that falls off like 1/r3?