ANS:B - Weber number

The number generally applied for the flow of liquid from an open-ended tube or nozzle, leading to the formation of a spray of liquid drops, is the Weber number. The Weber number (We) is a dimensionless parameter used in fluid mechanics to characterize the ratio of inertial forces to surface tension forces within a fluid flow. It's defined as: We=Inertial forces / Surface tension forces​ In the context of a liquid flow exiting an open-ended tube or nozzle, the Weber number is crucial in understanding the breakup of the liquid jet into droplets. It helps predict when the surface tension of the liquid is overcome by the inertial forces, resulting in the disintegration of the liquid into a spray of droplets. So, the correct answer is the Weber number.