| line of force n. pl. lines of force A theoretical line in a field of force, such that a tangent at any point gives the direction of the field at that point. |
| line of force
A line used to indicate the direction of a field, especially an electric or magnetic field, at various points in space. The tangent of a line of force at each point indicates the orientation of the field at that point. Arrows are usually used to indicate the direction of the force. See Note at magnetism. |