The document describes an experiment to determine the coefficient of discharge (C_d) of an orifice. The experiment involves measuring the differential head and discharge rate with varying water levels in a tank. The orifice diameter, water heights, times, and discharges are measured and used to calculate the theoretical and actual velocities. From these, the C_d values are calculated at different discharges and the mean C_d is determined. Graphs are plotted between the differential head, gauge readings, and discharge to analyze the results.