In alternating current, how often does the current alternate between negatively and postively?

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Water at 70°f and streams enter the mixing chamber at the same mass flow rate, determine the temperature and the quality of the exiting stream. 0 psia is heated in a chamber by mixing it with saturated water vapor at 20 psia. if both streams enters the mixing chamber at the same mass flow rate, determine the temperature and the quality of the existing system.

Draw the engineering stress-strain curve for (a) bcc; (b) fcc metals and mark important points.