IBEW Reading Comprehension Skills 3 — Questions and Answers
Question 1: A passage reads: 'Conduit fill is defined as the percentage of the conduit's cross-sectional area occupied by conductors. For three or more conductors, the maximum allowable fill is 40 percent.' If a conduit has a cross-sectional area of 1.00 square inch, what is the maximum fill area for three conductors?
- 0.25 square inch
- 0.33 square inch
- 0.40 square inch (Correct answer)
- 0.50 square inch
Correct answer: 0.40 square inch
40 percent of 1.00 square inch is 0.40 square inch, which is the maximum allowable conductor fill area.
Question 2: A memo states: 'All apprentices must complete a minimum of 144 hours of related technical instruction per year in addition to on-the-job training hours. Failure to meet this requirement may result in suspension of the apprenticeship.' What would happen if an apprentice completed only 120 hours of instruction?
- The apprentice would receive a warning only
- The apprenticeship could be suspended (Correct answer)
- The apprentice would need to retake failed courses only
- No consequence is stated for missing instruction hours
Correct answer: The apprenticeship could be suspended
The memo states that failure to meet the 144-hour minimum 'may result in suspension of the apprenticeship,' and 120 hours is below that minimum.
Question 3: A wiring diagram legend reads: 'Dashed lines indicate future or proposed wiring. Solid lines indicate existing wiring. Circles represent junction boxes.' On the diagram, a dashed line connects two circles. What does this represent?
- An existing cable connecting two junction boxes
- A proposed or future wire run between two junction boxes (Correct answer)
- A conduit run with no conductors installed
- A ground fault circuit between existing boxes
Correct answer: A proposed or future wire run between two junction boxes
According to the legend, dashed lines indicate future or proposed wiring, and circles represent junction boxes, so a dashed line between two circles shows a planned wire run.
Question 4: A safety rule states: 'Never work on energized equipment unless de-energizing creates a greater hazard or is infeasible due to equipment design or operational limitations.' This rule implies that working on energized equipment is:
- Strictly prohibited under all circumstances
- Acceptable whenever the worker feels confident
- Permissible only when specific conditions justify it (Correct answer)
- Required for all routine maintenance tasks
Correct answer: Permissible only when specific conditions justify it
The rule permits energized work only under specific conditions — when de-energizing creates greater hazard or is infeasible — not as a routine practice.
Question 5: An electrical specification reads: 'Wire connectors shall be listed and identified for the conductor material, size, and number of conductors being joined. Aluminum conductors shall not be connected to devices rated for copper conductors only.' A device marked 'CU ONLY' means:
- It can be used with copper or aluminum conductors
- It is approved for copper conductors exclusively (Correct answer)
- It requires special lugs for aluminum conductors
- It must be used with conductors of 10 AWG or larger
Correct answer: It is approved for copper conductors exclusively
'CU' is the chemical symbol for copper, so 'CU ONLY' on a device marking means it is rated for copper conductors only and must not be used with aluminum.
Question 6: A passage reads: 'The ampacity of a conductor is the maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.' What factor does this definition NOT mention?
- Temperature rating of the conductor
- Conditions of use
- Maximum continuous current
- Voltage drop across the conductor (Correct answer)
Correct answer: Voltage drop across the conductor
The definition addresses temperature rating, conditions of use, and maximum continuous current, but does not mention voltage drop.
Question 7: A work instruction reads: 'After completing rough-in wiring, all boxes must be covered with blank cover plates or device covers before the site is left unattended. Exposed energized parts are a violation of OSHA standards.' The MAIN reason for this requirement is to:
- Protect the boxes from paint damage during finishing
- Prevent accidental contact with exposed electrical parts (Correct answer)
- Keep dust and debris out of the boxes
- Allow inspectors to identify completed work easily
Correct answer: Prevent accidental contact with exposed electrical parts
The instruction explicitly references OSHA standards and 'exposed energized parts,' indicating the primary purpose is preventing accidental contact with live electrical components.
IBEW Reading Comprehension Skills 3
A passage reads: 'Conduit fill is defined as the percentage of the conduit's cross-sectional area occupied by conductors.
For three or more conductors, the maximum allowable fill is 40 percent.' If a conduit has a cross-sectional area of 1.00 square inch, what is the maximum fill area for three conductors?