What describes the pattern of flux lines around the center of a two-pole magnetic field?

What describes the pattern of flux lines around the center of a two-pole magnetic field?

• A. Concentric circles
• B. Zigzag lines
• C. Parallel lines
• D. Random curves

Answer: (C)

A uniform magnetic field between two flat, facing poles yields flux lines that run parallel. When the poles are large and the gap is fairly uniform, the magnetic lines emerge from the north pole and head straight toward the south pole, staying evenly spaced. In the region right between the poles, this appears as straight, parallel lines indicating a uniform field. Outside the gap, the lines curve to complete the loop from north to south, but the center areabetween the poles is well described by parallel lines. Other patterns would represent different geometries (concentric circles come from circular symmetry around a pole; zigzag or random curves would indicate irregular, nonuniform fields), so the parallel-line description best fits the center of a two-pole field.

A uniform magnetic field between two flat, facing poles yields flux lines that run parallel. When the poles are large and the gap is fairly uniform, the magnetic lines emerge from the north pole and head straight toward the south pole, staying evenly spaced. In the region right between the poles, this appears as straight, parallel lines indicating a uniform field. Outside the gap, the lines curve to complete the loop from north to south, but the center areabetween the poles is well described by parallel lines. Other patterns would represent different geometries (concentric circles come from circular symmetry around a pole; zigzag or random curves would indicate irregular, nonuniform fields), so the parallel-line description best fits the center of a two-pole field.