NCCER missed questions
A valve has a linear-flow characteristics when the:
differential pressure corresponds directly to the valve stem position
All the following valves are used to regulate flow, EXCEPT: plug, butterfly, needle
gate
When selecting a regulator, choose the:
overpressure protection that protects the regulator
Density is analyzed using all the following methods EXCEPT: Air bubbler, displacement, densitometer
peptide
A photosensor is
silicone-controlled rectifier
All of the following are typical applications of photocells EXCEPT: Automatic lighting control, position sensing, battery charging
size detection
A transmitter has a range 0-304.7" wc. What is the range in psi?
0-11 psi
The hydrostatic pressure created in a 10 foot tank with 8 feet water level is:
8 psi
Which of the following must be determined before selecting a pressure-reducing regulator?
Capacity required
The process parameter that is selected for control is called
Controlled variable
The word "piezoelectric" refers to a certain class of crystals that produce an electric signal when they are mechanically
Deformed
If the proportional band of a controller is adjusted to the MINIMUM possible value, the controller action is likely to be:
Excellent
All of the following are volumetric flow rates EXCEPT: SCFS, SCFM, SCFH
SCFH
Optimal gain is the maximum allowable value of gain in which the system is
Stable
"Proving" a loop involves
VERIFYING desired interaction of loop components through simulation
The device that is used to check the integrity of tubing is the
Wallace and Tieman calibrator
Which of the following adjustments on a pressure transmitter sets the minimum range value?
Zero
carbon dioxide is produced commercially
as a byproduct of manufacturing
A chemical, classified as a base, harms a human body by causing all the following EXCEPT: severe respiratory burns, dissolved skin tissue, irritation to nose and throat membranes
calcification of the tongue
Pressure is expressed mathematically as:
decreases when controller signal increases
Multiple instruments within a loop share a common:
loop number
Shift registers are designed to do all the following EXCEPT:
translate data within registers