By using a compass to measure the magnetic field direction at ...

[crobinson2013]

By using a compass to measure the magnetic field direction at various points adjacent to a long straight wire, you can show that the wire's magnetic field lines are
 a. straight lines in space that go from one magnetic charge to another.
  b. straight lines in space that are parallel to the wire. c. straight lines in space that are perpendicular to the wire. d. circles that have their centers on the wire and lie in planes perpendicular to the wire. e. circles that have the wire lying along a diameter of the circle.

Question 2

A current element (length = 1.0 cm) lies along the x axis with its center at x = 0 and carries a 20-A current in the positive x direction. Consider only the field of this current element and decide which combination of the following statements is correct. 1. The field at (0, 0, 1.0 m) is in the positive z direction. 2. The field at (0, 1.0 m, 0) is in the negative y direction. 3. The field at (1.0 m, 0, 0) is zero. 4. The field at (0, 0, 1.0 m) is in the negative y direction.
 a. 3 and 4
  b. 1 and 3
  c. 2 and 4
  d. 1 and 2
  e. None of these

[cassie_ragen]

Answer to Question 1

D

Answer to Question 2

A