Question

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. Which statement is true?

1) The electric field is always perpendicular to the equipotential lines.
2) The electric field is always parallel to the equipotential lines.
3) The electric field is always tangential to the equipotential lines.
4) The electric field is always zero on the equipotential lines.

Answer 1

The electric field is always perpendicular to the equipotential lines, as they are lines where the electric potential remains constant, and no electric force is experienced along them.

Step-by-step explanation:

When examining the relationship between the electric field and equipotential lines, it is important to remember that equipotential lines indicate places where the electric potential is constant. The key characteristic of the relationship between the electric field and equipotential lines is that the electric field is always perpendicular to the equipotential lines. This is best understood by reviewing the properties of electric fields and equipotential lines:

• An equipotential line is a line or surface over which the electric potential is the same at every point.
• Equipotential lines are always drawn perpendicular to electric field lines.
• The electric field is strongest where the field lines are closest together, and the direction of the electric field at a point is tangent to the electric field line.

Therefore, considering these properties, the correct statement from the options provided is that the electric field is always perpendicular to the equipotential lines. This is because the electric field lines represent the direction of the electric force on a positive charge and, since a charge experiences no force along an equipotential line (as there is no change in potential energy), the only direction it can experience a force is perpendicular to that line.