NCEES Electrical Engineering PE Exam

Question 1

On the NCEES PE Electrical exam, what does the 'power factor' of an AC circuit represent?

Accepted Answer

The ratio of real power to apparent power (cos θ)

Answer

Power factor (PF = cos θ = P/S) is the ratio of real (useful) power consumed to the apparent (total) power supplied, ranging from 0 to 1.

Question 2

In the NCEES PE Electrical exam, what is the purpose of a 'per-unit system' in power systems analysis?

Accepted Answer

To normalize quantities to a common base, simplifying calculations across transformers and voltage levels

Answer

The per-unit system normalizes voltages, currents, powers, and impedances to a chosen base, eliminating transformer turns ratios and simplifying multi-voltage-level system analysis.

Question 3

For the NCEES PE Electrical exam, which protection device operates based on time-current characteristics to interrupt overcurrents?

Accepted Answer

Overcurrent relay (inverse time)

Answer

Inverse-time overcurrent relays trip faster as current magnitude increases, providing coordination with downstream devices and protecting against sustained overloads and faults.

Question 4

On the NCEES PE Electrical exam, what is the 'synchronous reactance' of a synchronous generator?

Accepted Answer

The effective internal reactance that determines voltage regulation and fault current

Answer

Synchronous reactance (Xs) is the per-phase internal impedance of a synchronous machine, governing its voltage regulation, stability, and contribution to fault currents.

Question 5

In the NCEES PE Electrical exam, what does 'short-circuit MVA' (fault MVA) represent?

Accepted Answer

The magnitude of power available during a three-phase fault at a bus

Answer

Short-circuit MVA at a bus represents the severity of a three-phase fault, calculated as the product of the prefault voltage and the available fault current, used for equipment ratings.

NCEES National Council of Examiners for Engineering and Surveying Practice Practice Test

NCEES National Council of Examiners for Engineering and Surveying Practice Practice Test

NCEES Electrical Engineering PE Exam