A long wire lies in a tangle on the surface of a table, as shown below.When a current is run through the wire as shown, the largest component of the magnetic field at X points:
A)into the table.
B)out of the table.
C)parallel to the nearest segment of wire.
D)antiparallel to the nearest segment of wire.
E)along a circle which has its centre at the centre of the overall loop.

Question

A long wire lies in a tangle on the surface of a table, as shown below.When a current is run through the wire as shown, the largest component of the magnetic field at X points: 
A)into the table. 
B)out of the table. 
C)parallel to the nearest segment of wire. 
D)antiparallel to the nearest segment of wire. 
E)along a circle which has its centre at the centre of the overall loop.

Quizplus · Accepted Answer

According to the right-hand rule, when the current flows through the wire, it creates a magnetic field that loops around the wire in a counterclockwise direction (from above). At point X, the magnetic field lines are perpendicular to the plane of the wire and therefore perpendicular to the surface of the table. The only option that fits this description is option B, which states that the magnetic field is pointing out of the table.

A Long Wire Lies in a Tangle on the Surface