Troy must keep track of the amount of refrigerant he uses from a 50 pound cylinder to ensure that accurate records are kept he used 13 pounds on a system for ms Jones

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented