What is the most common and economical distribution system configuration?

Radial distribution system

True or False: Loop distribution systems are normally operated with all switches closed.

False. They are normally operated with a sectionalizing switch open.

Multiple Choice: Which voltage level is commonly used for medium voltage primary distribution?
A) 480V
B) 12.47kV
C) 34.5kV
D) 120V

B) 12.47kV

Fill in the blank: ANSI C84.1 Range A voltages are _____ of nominal voltage.

±5%

What transformer connection provides a 30° phase shift and grounded neutral availability?

Delta-Wye (Δ-Y) connection

True or False: Open-delta transformers can operate at 57.7% of closed-delta capacity.

True

Multiple Choice: What is the maximum voltage drop recommended by NEC for combined feeders and branch circuits?
A) 3%
B) 5%
C) 8%
D) 10%

B) 5%

Fill in the blank: Diversity factor is always _____ 1.0.

≥ (greater than or equal to)

What happens to line losses when power factor decreases?

Line losses increase (losses ∝ I²)

Multiple Choice: Ground fault protection per NEC 230.95 has maximum settings of:
A) 800A, 0.5s
B) 1200A, 1s
C) 1000A, 2s
D) 600A, 0.3s

B) 1200A, 1s

True or False: Demand factor is always less than or equal to 1.0.

True

Fill in the blank: Network distribution systems use _____ protectors for interconnection.

Network

What voltage levels are typically used for residential single-phase secondary distribution?

120/240V

Multiple Choice: Fuse-to-fuse coordination requires minimum separation of:
A) 50ms
B) 75ms
C) 100ms
D) 200ms

B) 75ms

True or False: Solidly grounded systems provide the fastest fault clearing times.

True

Fill in the blank: Type A voltage regulators use a _____V coil configuration.

120

What is the relationship between geometric mean distance and conductor reactance?

Reactance increases with larger GMD spacing

Multiple Choice: Transformer efficiency is highest when:
A) No-load losses equal load losses
B) Load losses are maximum
C) No-load losses are zero
D) Load current is minimum

A) No-load losses equal load losses

Fill in the blank: Equipment grounding conductors are sized per NEC Table _____.

250.122

What system grounding method limits fault current to reduce equipment damage?

Resistance grounded systems

True or False: Load tap changers can operate under load without service interruption.

True

Multiple Choice: Per-unit impedance helps simplify:
A) Voltage regulation
B) Short circuit analysis
C) Load calculations
D) Power factor correction

B) Short circuit analysis

Why do utilities impose power factor penalties below 0.90?

To encourage efficient reactive power usage and reduce system losses

Fill in the blank: Capacitor banks improve voltage by reducing _____ current flow.

Reactive