a wire in tube electrostatic precipitator having collecting electrodes of a total surface area 300 m2 is used to separate alkaline dust particles from a cement manufacturing plant.1200 m3/min,gases close in composition to atmospheric air ,at 95 oc, flow through the precipitator where 56000 volts potential is maintained between discharge and collecting electrodes, 12.5 cm apart. determine the migration velocity anf efficiency of separation for 0.1 micron particles.