Use the rule which you made up for remembering the relationship between the direction of the current flowing in a wire and the direction of the magnetic field near the wire to make a sketch showing the direction of the magnetic field near a wire which has a current flowing:

a) downward
b) horizontally

4. Physicists remember the orientation of the magnetic field of a current by placing their left thumb in the direction of the electric current and noting whether the fingers of their left hand curve clockwise or counterclockwise. Copy the following diagrams into your log. Use this rule to sketch the direction of the magnetic field in each case.

5. Imagine that a second vertical wire is placed in the apparatus used in this activity, but not touching the first wire. There is room to place a magnetic compass between the wires without touching either wire. If a compass were placed between the wires, describe in what direction the compass would point if the wires carry equal currents:

a) which are in opposite directions
b) which are in the same direction