The magnetic field 39.0 cm away from a long, straight wirecarrying current 4.00 A is 2050 nT.
(a) At what distance is it 205 nT?
cm
(b) At one instant, the two conductors in a long householdextension cord carry equal 4.00-A currents in opposite directions.The two wires are 3.00 mm apart. Find the magnetic field 39.0 cmaway from the middle of the straight cord, in the plane of the twowires.
nT
(c) At what distance is it one-tenth as large?
cm
(d) The center wire in a coaxial cable carries current 4.00 A inone direction, and the sheath around it carries current 4.00 A inthe opposite direction. What magnetic field does the cable createat points outside the cables?
nT
