CDCP General 3 — Questions and Answers
Question 1: Which metric measures the ratio of IT equipment power to total facility power consumption in a data center?
- Power Usage Effectiveness (PUE) (Correct answer)
- Data Center Infrastructure Efficiency (DCiE)
- Carbon Usage Effectiveness (CUE)
- Water Usage Effectiveness (WUE)
Correct answer: Power Usage Effectiveness (PUE)
PUE is the standard metric defined by The Green Grid that divides total facility power by IT equipment power.
Question 2: What does the 'N+1' redundancy model mean in data center design?
- One extra component beyond what is needed for normal operation (Correct answer)
- No redundancy is required
- All components are duplicated
- Two additional components beyond minimum requirements
Correct answer: One extra component beyond what is needed for normal operation
N+1 redundancy means one additional component beyond the minimum required (N) to handle failure of any single unit.
Question 3: What is the standard hot-aisle/cold-aisle arrangement in a data center?
- Server fronts face each other, backs face each other (Correct answer)
- All servers face the same direction
- Servers alternate randomly for airflow diversity
- Servers are arranged in a circular pattern
Correct answer: Server fronts face each other, backs face each other
Hot-aisle/cold-aisle containment places server fronts (intake) facing cold aisles and server backs (exhaust) facing hot aisles.
Question 4: According to ANSI/TIA-942, what is the highest data center tier classification?
- Tier I
- Tier II
- Tier III
- Tier IV (Correct answer)
Correct answer: Tier IV
Tier IV represents the highest level with fault-tolerant infrastructure allowing 99.9995% availability and simultaneous maintainability.
Question 5: What is the primary function of a Computer Room Air Handler (CRAH) unit?
- To cool server rooms using chilled water from a central plant (Correct answer)
- To generate electricity for IT equipment
- To monitor network traffic
- To provide fire suppression
Correct answer: To cool server rooms using chilled water from a central plant
CRAH units cool data center air by circulating it over coils supplied with chilled water from a central chiller plant.
Question 6: Which type of Uninterruptible Power Supply (UPS) technology provides the highest level of power protection with zero transfer time?
- Standby (offline) UPS
- Line-interactive UPS
- Double-conversion (online) UPS (Correct answer)
- Ferro-resonant UPS
Correct answer: Double-conversion (online) UPS
Double-conversion online UPS continuously converts AC to DC and back, keeping loads isolated from the raw utility with zero transfer time.
Question 7: What is the purpose of a Meets Point of Entry (MPOE) in a data center?
- The demarcation point where external network carriers hand off to the building owner (Correct answer)
- A physical security checkpoint for personnel
- A specialized power distribution panel
- The location of the main cooling plant
Correct answer: The demarcation point where external network carriers hand off to the building owner
The MPOE is the physical point where external telecommunications carriers terminate their service and responsibility transfers to the building owner.
CDCP General 3
Which metric measures the ratio of IT equipment power to total facility power consumption in a data center?