Electrokinectic phenomenon have gained considerable cognizance in this dynamic period of systems miniaturization and integration with respect to fabrication of micro devices (Lab-on-a-Chip Devices). Charged species such as DNA, RNA and Proteins are transported and separated in micro channels by applying Electric Field. Evolution of Lab-on-a-chip devices offers potentials for reduced sample volume, decreased time for analysis, reduced operating cost, increased accuracy and portability. Therefore, mobility measurements are critical to the quantification of motion of fluid and particles in micro analytical systems. However, to greatly minimize the time of analysis, it is important to move up to strong Electric Fields and low viscous suspending medium. Nevertheless, predictions of classical theory are limited to low field strength and does not give an idea of what happens at high fields, hence, a method of determining these mobilities in strong direct and oscillating field is presented. The strong field results appear to be consistent with the classical theories of electrokinectic phenomena. Fluid and particle velocities were found to be linearly dependent on the applied field and their mobilities were independent of the field even at strong field. Particle mobilities in direct and oscillating fields were found to be comparable. All these results were consistent with linear electrokinectic theory for low fields.