Three positive charges of equal value q are placed at the vertices of an equilateral triangle. The resulting electric field lines should be sketched as in
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → the diagram in Option (3)
Electric field lines start on positive charges and go outward; with no negative charge present they run off to infinity. They never cross and never form closed loops.
Option (1) — Incorrect. From the figure, the lines run from one charge to another. A field line can end only on a negative charge, so no line can join two positive charges.
Option (2) — Incorrect. From the figure, the curves wrap around each charge and a closed ring sits at the centre. Field lines leave a positive charge outward and cannot form closed loops.
Option (3) — Correct. From the figure, the lines leave each positive charge outward. They bend away from the other two charges because of mutual repulsion, and they never cross one another.
Option (4) — Incorrect. From the figure, the curves are closed loops around the charges. Electrostatic field lines never close on themselves. Closed curves of this kind look like equipotential surfaces.
NCERT (2026-27):
Electric Field Lines – “… The field lines follow some important general properties: (i) Field lines start from positive charges and end at negative charges. If there is a single charge, they may start or end at infinity. … (iii) Two field lines can never cross each other. … (iv) Electrostatic field lines do not form any closed loops.”