Question

3 phase sinusoidal volatge is applied to core type three phase transformer that can not itself give rise to any 3rd harmonic current.Also the Triplen flux in core type 3 phase transformer is precluded.The return paths of these fluxs lies outside cores through the air or oil and the walls of the tank.These paths are of very high reluctance and there is a strong tendency to retain a sinusoidal flux and emf.Then how third harmonic emf is induced to circulate non sinusoidal magnetizing current ( with third harmonic current) to have sinusoidal flux ( not flat topped) so that secondary induced volta