Question

Which of the following statements is not true about electric field lines?

• A. Electric field lines start from positive charge and end at negative charge.
• B. Two electric field lines can never cross each other.
• C. Electrostatic field lines do not form any closed loops.
• D. Electric field lines cannot be taken as continuous curve

Hint:

Remember the core difference for exams: Electric field lines are continuous curves that do not form closed loops, whereas magnetic field lines are continuous curves that do form closed loops. Spotting the word "cannot" in option (d) immediately flags it as the incorrect statement.

Answer 1

The Correct Option is D

Concept: Electric field lines are imaginary visual aids used to map the direction and spatial strength of an electric field in a region of space. They follow a strict set of fundamental properties derived from Coulomb's law and the conservative nature of electrostatic forces.

Step 1: Analyze the truth value of options (a), (b), and (c).
Let us systematically evaluate the established physical properties of electrostatic field lines:
• Statement (a): Electric field lines natively emerge and start from positive source charges and terminate radially inward on negative target charges. If there is a single isolated charge, they start or end at infinity. Thus, statement (a) is true.
• Statement (b): The tangent drawn to a field line at any point gives the unique direction of the net electric field vector ($\vec{E}$) at that point. If two lines crossed, it would mean that at that single intersection point, the field has two different directions simultaneously, which is physically impossible. Thus, statement (b) is true.
• Statement (c): Electrostatic fields are conservative in nature. Field lines originate at a positive source and end at a negative source; they cannot travel backward from a negative charge to a positive charge. Therefore, they do not form continuous closed loops (unlike magnetic field lines). Thus, statement (c) is true.

Step 2: Evaluate the incorrect statement (d).
An electric field exists continuously throughout a region surrounding a source charge distribution unless it encounters another localized point charge. A test charge moving in this space experiences a smooth, uninterrupted force. Consequently, electric field lines are continuous curves without any sudden breaks or gaps in charge-free space. Because statement (d) claims that they *cannot* be taken as continuous curves, it is not true. Therefore, it is our target correct option.