'चुम्बकीय क्षेत्र रेखाएँ' (magnetic field lines) की विशेषता है:

उत्तर: (C) They form closed loops from north to south pole — Magnetic field lines: closed loops (N to S outside, S to N inside magnet), never cross each other, closer lines = stronger field, tangent at any point gives field direction. Discovered using iron fili...