Certified Energy Manager (CEM) Practice Examination –
Part 1 Newest 2025 – 2026 Questions From Past Papers
Actual Exams Complete 100 Questions And Correct
Detailed Answers (Verified Answers) |Already Graded
A+||Brand New!!
Content covered (most tested areas on the official exam syllabus):
Energy management fundamentals, energy accounting and
economics, electrical systems, HVAC systems, motors and drives,
boilers and steam systems, lighting efficiency, building envelope,
renewable energy basics, measurement and verification, demand
management, and energy auditing.
1. A facility’s energy intensity is best defined as:
A. Total utility cost per year
B. Energy use relative to a measurable output
C. Electrical consumption only
D. Energy cost divided by maintenance cost
Answer: B. Energy use relative to a measurable output
Energy intensity compares energy use to production output, square footage, or
another operational metric to evaluate efficiency.
2. Which economic method accounts for the time value of money when
evaluating energy projects?
A. Simple payback
B. Net present value
C. Energy index
D. Demand factor
,Answer: B. Net present value
NPV discounts future cash flows to present value, making it a more accurate
financial evaluation tool.
3. The ratio of average load to peak load during a period is known as:
A. Power factor
B. Demand ratio
C. Load factor
D. Diversity factor
Answer: C. Load factor
Load factor indicates how efficiently electricity demand is used over time.
4. In a three-phase system, power is calculated using which formula?
A. P = VI
B. P = 3VI
C. P = √3 × V × I × PF
D. P = V²/R
Answer: C. √3 × V × I × PF
Three-phase power calculations include the square root of three and power factor.
5. Power factor improvement is typically achieved by installing:
A. Capacitors
B. Transformers
C. Resistors
D. Fuses
Answer: A. Capacitors
Capacitors offset inductive loads and improve power factor.
6. The primary function of a variable frequency drive (VFD) is to:
A. Increase motor torque
B. Reduce voltage fluctuations
C. Control motor speed
D. Increase electrical frequency
, Answer: C. Control motor speed
VFDs vary frequency and voltage supplied to motors to adjust speed efficiently.
7. Which lighting technology generally has the highest efficacy?
A. Incandescent
B. Halogen
C. LED
D. Mercury vapor
Answer: C. LED
LED lighting produces the most lumens per watt among common technologies.
8. The coefficient of performance (COP) of a refrigeration system is defined as:
A. Heat rejected divided by power input
B. Cooling provided divided by power input
C. Power input divided by cooling provided
D. Heat input divided by work output
Answer: B. Cooling provided divided by power input
COP measures efficiency of refrigeration equipment.
9. Economizers in HVAC systems are used to:
A. Increase refrigerant flow
B. Recover waste heat
C. Use outside air for cooling
D. Increase compressor efficiency
Answer: C. Use outside air for cooling
Air-side economizers reduce mechanical cooling by using cool outdoor air.
10.Which device measures electrical power consumption over time?
A. Ammeter
B. Wattmeter
C. Energy meter
D. Voltmeter
Part 1 Newest 2025 – 2026 Questions From Past Papers
Actual Exams Complete 100 Questions And Correct
Detailed Answers (Verified Answers) |Already Graded
A+||Brand New!!
Content covered (most tested areas on the official exam syllabus):
Energy management fundamentals, energy accounting and
economics, electrical systems, HVAC systems, motors and drives,
boilers and steam systems, lighting efficiency, building envelope,
renewable energy basics, measurement and verification, demand
management, and energy auditing.
1. A facility’s energy intensity is best defined as:
A. Total utility cost per year
B. Energy use relative to a measurable output
C. Electrical consumption only
D. Energy cost divided by maintenance cost
Answer: B. Energy use relative to a measurable output
Energy intensity compares energy use to production output, square footage, or
another operational metric to evaluate efficiency.
2. Which economic method accounts for the time value of money when
evaluating energy projects?
A. Simple payback
B. Net present value
C. Energy index
D. Demand factor
,Answer: B. Net present value
NPV discounts future cash flows to present value, making it a more accurate
financial evaluation tool.
3. The ratio of average load to peak load during a period is known as:
A. Power factor
B. Demand ratio
C. Load factor
D. Diversity factor
Answer: C. Load factor
Load factor indicates how efficiently electricity demand is used over time.
4. In a three-phase system, power is calculated using which formula?
A. P = VI
B. P = 3VI
C. P = √3 × V × I × PF
D. P = V²/R
Answer: C. √3 × V × I × PF
Three-phase power calculations include the square root of three and power factor.
5. Power factor improvement is typically achieved by installing:
A. Capacitors
B. Transformers
C. Resistors
D. Fuses
Answer: A. Capacitors
Capacitors offset inductive loads and improve power factor.
6. The primary function of a variable frequency drive (VFD) is to:
A. Increase motor torque
B. Reduce voltage fluctuations
C. Control motor speed
D. Increase electrical frequency
, Answer: C. Control motor speed
VFDs vary frequency and voltage supplied to motors to adjust speed efficiently.
7. Which lighting technology generally has the highest efficacy?
A. Incandescent
B. Halogen
C. LED
D. Mercury vapor
Answer: C. LED
LED lighting produces the most lumens per watt among common technologies.
8. The coefficient of performance (COP) of a refrigeration system is defined as:
A. Heat rejected divided by power input
B. Cooling provided divided by power input
C. Power input divided by cooling provided
D. Heat input divided by work output
Answer: B. Cooling provided divided by power input
COP measures efficiency of refrigeration equipment.
9. Economizers in HVAC systems are used to:
A. Increase refrigerant flow
B. Recover waste heat
C. Use outside air for cooling
D. Increase compressor efficiency
Answer: C. Use outside air for cooling
Air-side economizers reduce mechanical cooling by using cool outdoor air.
10.Which device measures electrical power consumption over time?
A. Ammeter
B. Wattmeter
C. Energy meter
D. Voltmeter
