CITY & GUILDS 2365 UNIT 614 MOCK
EXAM - ENVIRONMENTAL
TECHNOLOGY SYSTEMS| QUESTIONS
AND ANSWERS |2026/2027 UPDATE |
JUST RELEASED
1. Which of the following describes the ‘Coefficient of Performance’ (COP) for a heat pump
system?
A. The ratio of heat output to electrical energy input
B. The ratio of electricity input to heat output
C. The total heat energy produced in one calendar year
D. The difference between the outdoor temperature and the indoor flow temperature
Answer: A
Conceptual Explanation: COP is defined as the heat energy output divided by the
electrical energy input. A COP of 3 means 3kW of heat is produced for every 1kW of
electricity used.
,2. In a grid-connected Solar PV system, what is the primary purpose of a DC isolator?
A. To switch off the AC supply to the inverter
B. To disconnect the PV string from the inverter for safe maintenance
C. To prevent the batteries from overcharging
D. To regulate the voltage output from the panels
Answer: B
Conceptual Explanation: The DC isolator is essential for isolating the DC voltage
generated by the PV array from the inverter, allowing for maintenance or repair work
without the risk of electric shock from the live DC strings.
3. Under the Microgeneration Certification Scheme (MCS), what is the maximum output limit
for a single-phase micro-wind turbine to be classified as ‘microgeneration’?
A. 5 kW
B. 10 kW
C. 50 kW
D. 100 kW
Answer: C
Conceptual Explanation: MCS defines microgeneration as electricity production up to 50
kW and heat production up to 45 kW thermal.
, 4. Which component in a solar thermal system prevents the heat transfer fluid from boiling
during periods of excess heat (stagnation)?
A. Expansion vessel
B. Check valve
C. Flow meter
D. Non-return valve
Answer: A
Conceptual Explanation: The expansion vessel accommodates the expansion of the fluid
as it heats up and helps manage pressure during stagnation to prevent system damage.
5. What is the function of a ‘bypass diode’ in a Solar PV module?
A. To allow current to flow around shaded or damaged cells
B. To increase the voltage of the string
C. To convert DC to AC directly at the module
D. To prevent current from flowing back into the module at night
Answer: A
Conceptual Explanation: Bypass diodes reduce the power loss caused by shading by
allowing current to bypass the high-resistance shaded cells, preventing hotspots.
EXAM - ENVIRONMENTAL
TECHNOLOGY SYSTEMS| QUESTIONS
AND ANSWERS |2026/2027 UPDATE |
JUST RELEASED
1. Which of the following describes the ‘Coefficient of Performance’ (COP) for a heat pump
system?
A. The ratio of heat output to electrical energy input
B. The ratio of electricity input to heat output
C. The total heat energy produced in one calendar year
D. The difference between the outdoor temperature and the indoor flow temperature
Answer: A
Conceptual Explanation: COP is defined as the heat energy output divided by the
electrical energy input. A COP of 3 means 3kW of heat is produced for every 1kW of
electricity used.
,2. In a grid-connected Solar PV system, what is the primary purpose of a DC isolator?
A. To switch off the AC supply to the inverter
B. To disconnect the PV string from the inverter for safe maintenance
C. To prevent the batteries from overcharging
D. To regulate the voltage output from the panels
Answer: B
Conceptual Explanation: The DC isolator is essential for isolating the DC voltage
generated by the PV array from the inverter, allowing for maintenance or repair work
without the risk of electric shock from the live DC strings.
3. Under the Microgeneration Certification Scheme (MCS), what is the maximum output limit
for a single-phase micro-wind turbine to be classified as ‘microgeneration’?
A. 5 kW
B. 10 kW
C. 50 kW
D. 100 kW
Answer: C
Conceptual Explanation: MCS defines microgeneration as electricity production up to 50
kW and heat production up to 45 kW thermal.
, 4. Which component in a solar thermal system prevents the heat transfer fluid from boiling
during periods of excess heat (stagnation)?
A. Expansion vessel
B. Check valve
C. Flow meter
D. Non-return valve
Answer: A
Conceptual Explanation: The expansion vessel accommodates the expansion of the fluid
as it heats up and helps manage pressure during stagnation to prevent system damage.
5. What is the function of a ‘bypass diode’ in a Solar PV module?
A. To allow current to flow around shaded or damaged cells
B. To increase the voltage of the string
C. To convert DC to AC directly at the module
D. To prevent current from flowing back into the module at night
Answer: A
Conceptual Explanation: Bypass diodes reduce the power loss caused by shading by
allowing current to bypass the high-resistance shaded cells, preventing hotspots.
