What is the difference between an open circuit and an open aev?

Answer 1

This is copied from Section 6.11, Question 8 in "Modern Refrigeration and Air Conditioning." The answer is (B), "The open circuit prevents flow. The open AEV allows flow to occur." Although a bit obscure, the answer is correct because, within the context of an electrical circuit, an "open circuit" (i.e. disconnected wire) would prevent the flow of electrical current. Within the context of a refrigeration circuit, an open AEV (automatic expansion valve) would permit the flow of refrigerant into an evaporator coil to provide cooling.