Question

For an infinite line charge (infinite cylinder configuration), the equipotential surfaces are:

Options

• Curved lines from the axis to infinity

• Co-axial cylinders

• Concentric spheres centred on the axis

• Parallel planes perpendicular to the axis

Answer 1

For a line charge (infinite cylinder), the equipotential surfaces are co-axial cylinders, with field lines directed radially outward from the axis. This geometry ensures the field is perpendicular to the cylindrical equipotential surfaces at every point.