01 Electric field lines are only a pictorial tool. Which two features can be inferred most reliably from them?
Answer and explanation
Correct answer: A. The field direction and its relative strength
Explanation: Electric field lines are an illustrative representation, not physical threads. The arrow or tangent to a line gives the direction of the electric field at that point, defined as the force direction on a positive test charge. The number or density of lines per unit area indicates relative field strength: closer lines mean a stronger field. Thus A is correct; the other choices are not encoded by field-line diagrams.