112+ Free C&G 2079-11 F-Gas Category I Practice Questions

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ArticleIs City & Guilds 2079-11 Still Valid in 2026?12 min read

2026 Statistics

Key Facts: C&G 2079-11 F-Gas Category I Exam

Online Questions

City & Guilds 2079-101 specification

80 min

Online Test Time

City & Guilds 2079-101 specification

Pass/Fail

Published Result Standard

Public specification

31 Dec 2027

Last Registration

City & Guilds

31 Dec 2030

Last Certification

City & Guilds

£82.30

Published Qualification Fee

City & Guilds

City & Guilds 2079-11 remains an active Category I route in 2026, with last registration on 31 December 2027 and last certification on 31 December 2030. Assessment is a 40-question, 80-minute online test plus a practical assignment. The public specification reports Pass/Fail but no numeric cut. Legal recognition differs across Great Britain, Northern Ireland, and the EU, and personal qualification does not replace company certification where required.

Sample C&G 2079-11 F-Gas Category I Practice Questions

Try these sample questions to test your C&G 2079-11 F-Gas Category I exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 112+ question experience with AI tutoring.

1In a basic vapour-compression refrigeration cycle, which component absorbs heat from the space or product being cooled?

A.The condenser

B.The compressor

C.The evaporator

D.The expansion valve

Explanation: The evaporator is where low-pressure liquid refrigerant boils (evaporates), absorbing latent heat from the surrounding air or product and producing the cooling effect. The other three components either reject heat, raise pressure, or reduce pressure.

2Which of the four main refrigeration components raises the pressure and temperature of the refrigerant vapour?

A.The evaporator

B.The compressor

C.The condenser

D.The receiver

Explanation: The compressor draws in low-pressure superheated vapour from the evaporator and compresses it, raising both its pressure and temperature so that it can subsequently reject heat in the condenser. It is the only component that adds work to the system.

3What happens to the refrigerant as it passes through the expansion (throttling) device?

A.Its pressure and temperature both fall

B.Its pressure rises and temperature falls

C.Its pressure and temperature both rise

D.Its enthalpy increases sharply

Explanation: The expansion valve or capillary tube throttles high-pressure liquid to low pressure. Both pressure and temperature drop, and a small fraction of the liquid flash-evaporates. The process is essentially constant-enthalpy (isenthalpic), shown as a vertical line on the p-h diagram.

4On a pressure-enthalpy (p-h) diagram, the throttling process through the expansion valve is represented by which type of line?

A.A horizontal line of constant pressure

B.A vertical line of constant enthalpy

C.A curved line following the saturation dome

D.A diagonal line of constant entropy

Explanation: Throttling is an isenthalpic process: enthalpy is constant, so it appears as a vertical line on the p-h diagram (enthalpy on the horizontal axis, pressure on the vertical axis). Pressure drops while enthalpy stays the same.

5What is meant by 'superheat' in a refrigeration system?

A.The temperature of the refrigerant above its saturation temperature in the vapour state

B.The temperature of the liquid below its saturation temperature

C.The pressure rise across the compressor

D.The latent heat absorbed in the evaporator

Explanation: Superheat is the number of degrees the refrigerant vapour is heated above its saturation (boiling) temperature at the prevailing pressure. Adequate superheat at the compressor suction protects the compressor from liquid floodback (liquid slugging).

6What does 'sub-cooling' describe in the refrigeration cycle?

A.Cooling the vapour leaving the compressor

B.Cooling the liquid refrigerant below its saturation temperature

C.Heating the vapour above its saturation temperature

D.Reducing the suction pressure

Explanation: Sub-cooling is cooling the liquid refrigerant leaving the condenser to below its saturation temperature for the prevailing pressure. It ensures only liquid (not flash gas) enters the expansion device, improving capacity and efficiency.

7In the evaporator, refrigerant absorbs heat mainly by which mechanism?

A.Sensible heating of the vapour

B.Latent heat of vaporisation as the liquid boils

C.Heat of compression

D.Conduction through the receiver

Explanation: Inside the evaporator the low-pressure liquid refrigerant boils, absorbing latent heat of vaporisation from the air or product. Because a phase change absorbs a large amount of energy at constant temperature, this is what gives the system its cooling capacity.

8Which statement about the condenser in a vapour-compression system is correct?

A.It boils the refrigerant at low pressure

B.It rejects heat and condenses the high-pressure vapour to liquid

C.It reduces the refrigerant pressure

D.It compresses the refrigerant vapour

Explanation: The condenser receives hot, high-pressure superheated vapour from the compressor, de-superheats it, then condenses it to liquid by rejecting heat to the ambient air or water. The total heat rejected equals the cooling load plus the compressor work.

9On a p-h diagram, the area inside the curved 'saturation dome' represents refrigerant that is in which state?

A.Sub-cooled liquid only

B.Superheated vapour only

C.A mixture of liquid and vapour (two-phase)

D.Supercritical fluid

Explanation: The region under the saturation dome is the two-phase region, where liquid and vapour coexist. To the left of the dome the refrigerant is sub-cooled liquid; to the right it is superheated vapour. Evaporation and condensation both take place inside the dome at constant pressure.

10Why must liquid refrigerant be prevented from returning to the compressor suction?

A.Liquid is incompressible and can cause mechanical damage (liquid slugging)

B.Liquid lowers the system GWP

C.Liquid increases superheat

D.Liquid improves lubrication

Explanation: Liquid refrigerant is effectively incompressible, so if it reaches the compressor cylinders it can cause hydraulic shock or 'liquid slugging', damaging valves and bearings. Maintaining adequate suction superheat ensures only vapour enters the compressor.

About the C&G 2079-11 F-Gas Category I Exam

The City & Guilds 2079 Level 2 Award in F-Gas & ODS Regulations (Category I, qualification number 2079-11) is the UK certificate of competence required to legally handle fluorinated gases on stationary refrigeration, air-conditioning and heat-pump equipment. Category I covers all activities, leak checking, recovery, installation, service and maintenance, on systems of any charge size. Assessment is a 40-question on-screen multiple-choice exam (60% to pass) plus a practical assessment.

Assessment

40 on-screen (GOLA) multiple-choice questions over 80 minutes plus a practical assessment, graded Pass/Fail; 60% (24/40) is required on the theory paper. This practice bank is 100 selected-response items.

Time Limit

80 minutes (multiple-choice paper)

Passing Score

Pass/Fail; numeric cut score not published in the public specification

Exam Fee

£82.30 City & Guilds qualification fee plus approved-centre charges (City & Guilds (delivered through approved training centres))