Question

why a monopole magnet doesn't exist? ??

Answer 1

because a magnate must have two pole without two poles magnetic fields cannot be defined

Answer 2

Magnetic mono-pole does not exists, because magnetic field lines always forms a closd loop. If it arises from one pole, then it has to terminate on other one, to form close loops, which is opposite pole, hence due to this property magnets always found in dipole.. but by some special method,scientists created monopole in lab, but it is not permanent,,,