EstatePass

Special Occupancies — Texas Master Practice Questions

6 questions · 3% of the Calculations exam

Worked questions

1. A lighting design specifies an average illuminance of 1 foot-candle over 100 square feet. No luminaire efficacy or light-distribution data are supplied. What electrical lighting power can be determined from these facts alone?

  • AExactly 100 watts
  • BExactly 200 watts
  • The electrical power cannot be determined from these facts alone
  • DExactly 1000 watts

Where to look it up

https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b9

Why C is correct

One foot-candle is one lumen per square foot. The specified average illuminance over 100 square feet therefore corresponds to 100 lumens arriving at the area. Converting this into electrical watts requires the lighting equipment efficiency and how much of its light reaches the area. These data do not establish lamp power or emergency-lighting compliance.

2. A care facility has 200 single-occupancy rooms. A specified maintenance task calls for replacing exactly one existing smoke alarm in each of those single-occupancy rooms. How many replacement alarms are needed for this task?

  • 200
  • B400
  • C500
  • D600

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why A is correct

The specified task requires 200 × 1 = 200 replacement alarms. This counts only the described replacements; it does not establish how many alarms the building must have or verify the existing alarm design. No floor area or coverage assumption is needed.

3. A manufacturing plant has a fire-alarm load requiring 20 VDC at 5 A. It is supplied through a rectifier/regulator by a transformer with a 120 VAC primary and a 24 VAC secondary. At the maximum continuous load, the rectifier/regulator has 80% real-power conversion efficiency and a true input power factor of 0.75 at the transformer secondary; it supplies no other loads. All candidate transformers meet the design’s voltage, regulation, inrush, waveform and listing requirements at this load; only continuous VA rating differs. Which offered transformer VA rating is the smallest adequate choice?

  • A120VA
  • 240VA
  • C600VA
  • D1200VA

Where to look it up

https://www2.xppower.com/portals/0/brochures/Essential_Guide_to_Power_Supplies.pdf

Why B is correct

DC load = 20 V × 5 A = 100 W. The converter needs 100 ÷ 0.80 = 125 W from the transformer. Its apparent input demand is 125 ÷ 0.75 = 166.67 VA. Choose 240 VA, B: 120 VA is insufficient, while 600 VA and 1200 VA exceed the smallest adequate choice. Conversion efficiency relates real input and output watts; power factor relates input watts to AC volt-amperes. Neither can be silently assumed to be 100%. Sources: XP Power, Essential Guide to Power Supplies, Calculating Power Supply Efficiency, page 41: https://www2.xppower.com/portals/0/brochures/Essential_Guide_to_Power_Supplies.pdf ; Hammond Manufacturing, Design Guide for Rectifier Use: https://www.hammfg.com/electronics/transformers/rectifier

4. A university dormitory has 500 single-occupancy rooms. A specified maintenance task calls for replacing exactly one existing smoke alarm in each of those single-occupancy rooms. How many replacement alarms are needed for this task?

  • 500
  • B1,000
  • C2,000
  • D5,000

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why A is correct

The specified task requires 500 × 1 = 500 replacement alarms. This counts only the described replacements; it does not establish how many alarms the building must have or verify the existing alarm design. No floor area or coverage assumption is needed.

5. A warehouse has a fire-alarm load requiring 20 VDC at 10 A. It is supplied through a rectifier/regulator by a transformer with a 120 VAC primary and a 24 VAC secondary. At the maximum continuous load, the rectifier/regulator has 80% real-power conversion efficiency and a true input power factor of 0.75 at the transformer secondary; it supplies no other loads. All candidate transformers meet the design’s voltage, regulation, inrush, waveform and listing requirements at this load; only continuous VA rating differs. Which offered transformer VA rating is the smallest adequate choice?

  • A120VA
  • B240VA
  • 600VA
  • D1200VA

Where to look it up

https://www2.xppower.com/portals/0/brochures/Essential_Guide_to_Power_Supplies.pdf

Why C is correct

DC load = 20 V × 10 A = 200 W. The converter needs 200 ÷ 0.80 = 250 W from the transformer. Its apparent input demand is 250 ÷ 0.75 = 333.33 VA. Choose 600 VA, C: 120 VA and 240 VA are insufficient, while 1200 VA exceeds the smallest adequate choice. Conversion efficiency relates real input and output watts; power factor relates input watts to AC volt-amperes. Neither can be silently assumed to be 100%. Sources: XP Power, Essential Guide to Power Supplies, Calculating Power Supply Efficiency, page 41: https://www2.xppower.com/portals/0/brochures/Essential_Guide_to_Power_Supplies.pdf ; Hammond Manufacturing, Design Guide for Rectifier Use: https://www.hammfg.com/electronics/transformers/rectifier

6. A apartment building has 100 units. A specified maintenance task calls for replacing exactly one existing smoke alarm in each of those units. How many replacement alarms are needed for this task?

  • 100
  • B200
  • C300
  • D400

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why A is correct

The specified task requires 100 × 1 = 100 replacement alarms. This counts only the described replacements; it does not establish how many alarms the building must have or verify the existing alarm design. No floor area or coverage assumption is needed.

Practice all 6 Special Occupancies questions

Plus timed mock exams and a wrong book that follows you between the web and the app.

Start studying free

Other Texas Master content areas