Liquid mixtures are indispensable in almost all industries and all biological sciences. There exists an imperative need to understand these systems and to be able to predict their behavior from the molecular point of view. The use of measurable macroscopic quantities to probe into the microscopic, or the local properties of the system has become an essential area of research. The present investigation is aimed to explore the molecular interactions between the unlike molecules of the binary liquid mixtures of N-Methyll-2-Pyrrolidone (NMP), an industrially useful solvent, with reference to dipole-dipole and hydrogen bond interactions with the help of spectral, thermodynamic, acoustic, transport data of these mixtures. Additionally, the experimental data is used to test the applicability of empirical relations McAllister (4-body model) and Hind et al etc. models for viscosity. Also, the effect of temperature on the shapes of the interacting molecules is analyzed using Scaled Particle Theory. Further, to realize the nature of molecular interactions between the liquids, DFT calculations were carried out besides using SPARTON 08 Molecular Modeling software for IR analysis in this study