The demerits or limitations of bohr's atomic model are:
(1) it can only explain the spectrum of one electron system but failed to explain the complex spectrum of multielectron system.
(2) it predicts that in hydrogen spectra, a series of lines exists.however , as sprectrograph of high resolving power was developed , it was realised that what had been thought to be a single line , it actually consisted of two or more lines very close together.this is known as fine spectrum.
(3) This model is two dimensional while an atom is three dimensional.