Magnetic field due a (long) straight current

Sample problem: A long pair of wires serves to conduct 20 A of dc current to (and from) an instrument. If the wires are of negligible diameter but are 2.8 mm apart, what is the magnetic field 10 cm from their midpoint, in their plane. Compare to the magnetic field of the Earth.
Solution:

Sample problem: To construct a solenoid, you wrap insulated wire uniformly around a plastic tube 12 cm in diameter and 45 cm in length. You would like a 2-A current to produce a 2.7-kG magnetic field inside your solenoid. What is the total length of wire you will need to meet these specifications?
Solution:


Return to class notes TOC.

Page last modified: