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TL;DR

Master electrical load calculations including demand factors and service sizing. Accurate load calculations are essential for safe electrical design and a major exam topic.

By Valenke Exam Prep Team·Last updated 2026-06-03

Free Demand Factors (Tables 220.42/54/55) Practice Questions

Journeyman Electrician License Exam · Load Calculations

This module covers Demand Factors (Tables 220.42/54/55) as part of the Load Calculations section, testing your understanding of core concepts and their practical application.

ExamJourneyman Electrician License Exam
Pass Rate55%
Duration240 minutes
ModuleDemand Factors (Tables 220.42/54/55)

Why Demand Factors (Tables 220.42/54/55) matters

Demand Factors (Tables 220.42/54/55) is a commonly tested topic on the Journeyman Electrician License Exam because it covers fundamental knowledge required for competent professional practice.

Sample Practice Questions (5)

1. An apartment building has 10 dwelling units, each with a clothes dryer rated at 5,500 VA. Per Table 220.54, what is the total demand for the dryers? (Table 220.54: 10 dryers = 50% demand factor.)

  • 55,000 VA
  • 27,500 VA
  • 25,000 VA
  • 41,250 VA

2. A dwelling has a separate cooktop rated at 6 kW and two wall-mounted ovens each rated at 4 kW. Per NEC 220.55, how should these be treated?

  • Each appliance is calculated separately at nameplate rating
  • They are added together (14 kW) and treated as a single range per Table 220.55
  • Only the cooktop is calculated; ovens are excluded
  • Each is calculated at 80% demand factor individually

3. Using NEC Table 220.55 with Note 1, a dwelling has a single 14 kW range. The Column C demand for one range (not over 12 kW) is 8 kW. What is the adjusted demand?

  • 8,000 W
  • 8,400 W
  • 8,800 W
  • 9,200 W

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4. An apartment building has 8 dwelling units, each with a 10 kW electric range. Per Table 220.55, Column C, what is the demand load for all ranges?

  • 23 kW
  • 40 kW
  • 80 kW
  • 32 kW

5. Per NEC Table 220.55 Note 1, if a range is rated over 12 kW but not over 27 kW, the Column C demand from the table shall be increased by what percentage for each kW (or major fraction thereof) that exceeds 12 kW?

  • 3%
  • 5%
  • 10%
  • 15%

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Frequently Asked Questions

How many Demand Factors (Tables 220.42/54/55) questions are on the Journeyman Electrician License Exam?▼
The Load Calculations section, which includes Demand Factors (Tables 220.42/54/55), typically represents a significant portion of the exam. Focus on understanding core concepts rather than memorizing exact question counts, as the exam uses adaptive testing.
What is the best way to study Demand Factors (Tables 220.42/54/55)?▼
Use active recall and spaced repetition rather than passive reading. Practice with realistic exam questions, review explanations for both correct and incorrect answers, and focus on understanding the reasoning behind each concept.
What topics within Demand Factors (Tables 220.42/54/55) should I focus on most?▼
Focus on the concepts that appear in our practice questions and any areas where you consistently score below 70%. The adaptive practice mode will automatically target your weak areas for efficient study.