Question

(a)define magnetic field line. (b)Magnetic field line are closed curved .justify this statement

Answer 1

a) magnetic field lines - A magnetic field is represented by a series of lines (or paths ) around a magnet. The path (straight or curved ) along which unit north pole moves in a magnetic field is called magnetic field lines.
b) Magnetic field lines are closed and continuous curves as they emerge from N- pole and enter the magnet at S - pole. But magnetic field lines run from S-pole to N- pole within the magnet.