Questions

The formation of frost on cooling coils in a refrigerator Increases power consumption.

Answer A is reversed. Answer C is sometimes mistakenly used to forecast project completion (it’s invalid because it does not take into consideration which completed tasks are on the critical path). Answer D is the definition of Schedule Variance. 

The two main components of air are nitrogen and oxygen. They are seperated by the fractional distillation of liquid air. Liquefied air contains liquid nitrogen and liquid oxygen. Liquid nitrogen with the lower boiling point more readily evaporates than the less volatile liquid oxygen.