When a hydrogen atom is bound to a strongly electronegative atom, the mutual pair of electrons moves away from the hydrogen atom and towards the electronegative atom called as H-bonding.
The strength or magnitude of H-bond is determined by the compounds physical state.
In the solid state it reaches a maximum value, while in the gaseous state it approaches a minimum value.
The magnitude of the strength of the particles is maximum in solids, As for the strength of the bond interactions are most in solids thus it is obvious to say that the strength of the Hydrogen bond is maximum in solids and least in gases.
Therefore, magnitude of H-bond is maximum in Solids.