Free Practice Quiz Question List

2 Refrigerant Pressure Fundamentals Online Quiz Questions

Use this free practice quiz with 20 questions to review 2 Refrigerant Pressure Fundamentals, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

For a particular refrigerant, increasing pressure raises its saturation temperature.

A
True
B
False

Choose one

1 point

Which statement correctly distinguishes psig from psia?

A
Psig is measured relative to a vacuum, while psia is measured relative to atmospheric pressure.
B
Psig is measured relative to atmospheric pressure, while psia is measured relative to a vacuum.
C
Psig and psia both measure pressure relative to atmospheric pressure.
D
Psig and psia both measure pressure relative to a vacuum.

Written response

1 point

What is the standard term for the temperature at which liquid and vapor can coexist at a given pressure?

Fill in the blank

1 point

A P–T chart gives a saturation temperature of $40^\circ\mathrm{F}$ at the suction pressure. If the suction-line vapor temperature is $50^\circ\mathrm{F}$ , the superheat is °F.

Choose one

1 point

Which description best explains the pressure and heat-transfer roles of the evaporator and condenser in a typical vapor-compression system?

A
The evaporator operates at higher pressure to condense refrigerant, while the condenser operates at lower pressure to boil it.
B
Both the evaporator and condenser operate at the same pressure, but different temperatures.
C
The evaporator operates at lower pressure for boiling and heat absorption; the condenser operates at higher pressure for condensation and heat rejection.
D
The evaporator and condenser both operate at lower pressure so refrigerant can absorb heat.

True or false

1 point

A single pressure reading, by itself, is enough to establish whether a system has the correct refrigerant charge.

A
True
B
False

Fill in the blank

1 point

At the measured liquid-line pressure, the saturation temperature is $100^\circ\mathrm{F}$ . If the liquid-line temperature is $90^\circ\mathrm{F}$ , the subcooling is °F.

Written response

1 point

At sea level, convert a gauge reading of $20\ \mathrm{psig}$ to absolute pressure. Use $P_{\mathrm{psia}} \approx P_{\mathrm{psig}} + 14.7\ \mathrm{psi}$ . Enter the result in psia.

Choose all

1 point

Which factors can affect operating pressure in a refrigeration system? Select all that apply.

A
The amount of heat entering the evaporator
B
Outdoor temperature and condenser heat rejection
C
Airflow, water flow, or heat-exchanger condition
D
Compressor cycling, variable speed, or capacity controls
E
Pressure drop and where the pressure is measured
F
Which refrigerant is in the system
G
The color of the system cabinet

Choose one

1 point

For a refrigerant blend with temperature glide, which saturation references should be used to calculate vapor-side superheat and liquid-side subcooling, respectively?

A
Use bubble-point data for vapor-side superheat and dew-point data for liquid-side subcooling.
B
Use dew-point data for vapor-side superheat and bubble-point data for liquid-side subcooling.
C
Use dew-point data for both calculations.
D
Use bubble-point data for both calculations.

Choose all

1 point

A technician wants to interpret a service-port pressure reading meaningfully. Which steps or considerations support that interpretation? Select all that apply.

A
Identify the refrigerant and use its matching P–T chart.
B
Pair the pressure with a temperature measurement from the relevant system location.
C
Compare the results with equipment specifications and account for load and ambient conditions.
D
Consider whether the pressure measurement location differs from the location being evaluated.
E
Treat any pressure value as conclusive without checking refrigerant identity or operating conditions.
F
Use a P–T chart for any refrigerant because pressure has the same saturation relationship in all refrigerants.

Open ended

1 point

Explain how a greater heat load entering the evaporator, compared with a lighter load, can affect evaporating temperature and pressure. Include why this relationship should not be treated as a guaranteed outcome in every operating situation.

Choose one

1 point

In a typical vapor-compression system, which component creates much of the pressure difference between the evaporator and condenser?

A
The metering device creates all of the system’s pressure difference.
B
The evaporator creates the entire pressure difference by absorbing heat.
C
The compressor creates much of the pressure difference between the low-pressure and high-pressure sides.
D
The condenser alone creates the pressure difference by rejecting heat.

Choose one

1 point

For the same refrigerant, what happens to saturation temperature when pressure increases?

A
Its saturation temperature rises.
B
Its saturation temperature falls.
C
Its saturation temperature stays the same.
D
Its saturation temperature becomes independent of the refrigerant.

True or false

1 point

In a typical vapor-compression system, the evaporator operates at lower pressure than the condenser.

A
True
B
False

Choose one

1 point

At sea level, a gauge reads $18$ psig. Approximately what absolute pressure does this correspond to?

A
32.7 psia
B
18 psia
C
3.3 psia
D
32.0 psia

Written response

1 point

A matching refrigerant chart gives a suction-pressure saturation temperature of $40^\circ\mathrm{F}$ . The measured suction-line vapor temperature is $50^\circ\mathrm{F}$ . What is the superheat?

Choose one

1 point

A technician has a pressure reading but is unsure which pressure–temperature chart to consult. Which approach gives a valid saturation-temperature interpretation?

A
Use any available refrigerant chart because pressure determines the same saturation temperature for all refrigerants.
B
Use a pressure–temperature chart or property data for the refrigerant in the system.
C
Use the chart for the refrigerant with the closest name.
D
Interpret pressure without converting it to saturation temperature.

Choose one

1 point

A system is operating with warmer outdoor air and restricted condenser heat rejection. Which pressure change is consistent with these conditions?

A
Condensing pressure must fall because the refrigerant rejects more heat.
B
Condensing pressure remains fixed because it depends only on refrigerant choice.
C
Condensing temperature and pressure can rise.
D
Only evaporating pressure can change.

Written response

1 point

At the measured liquid-line pressure, the saturation temperature is $100^\circ\mathrm{F}$ , and the measured liquid-line temperature is $90^\circ\mathrm{F}$ . What is the subcooling?

2 Refrigerant Pressure Fundamentals Online Quiz Questions

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