Most switches used for safety controls in HVACR circuits:
A) Are normally closed and wired in series with the load they protect.
B) Are normally open and wired in parallel with the load they protect.
C) Are normally closed and wired in parallel with the load they protect.
D) Are normally open and wired in series with the load they protect.
Question 2
The simplest plasma arc cutting units use filtered _____.
a. carbon dioxide
b. nitrogen
c. compressed air
d. helium