Free Red Seal Industrial Electrician Examination Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Red Seal Industrial Electrician Examination practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1During a group lockout, four different workers apply, tag, inspect and authorize an isolation lock. Under the CCOHS lockout guidance, who keeps the key for that lock while servicing proceeds?

   1. A.The worker who inspected the lock
   2. B.The worker who applied the lockCorrect answer: B
   3. C.The worker who authorized the lock
   4. D.The worker who tagged the lock

   Explanation: CCOHS states: "All keys must be removed from locks and kept with the person who applied the lock." The person who applied this lock therefore retains its key; the other identified roles do not determine custody.

   Reference: CCOHS: Lockout/Tag out — What are the basic steps of locking and tagging out a system?, 6. Lockout/Tag Out

2. 2An electrician must select a test instrument for a three-phase utility service entrance. Assuming an adequate voltage rating, which IEC measurement category corresponds to that location?

   1. A.CAT I
   2. B.CAT II
   3. C.CAT III
   4. D.CAT IVCorrect answer: D

   Explanation: Fluke's IEC category overview identifies "CAT IV — 3-phase at the utility connection, outdoor conductors, electricity meters, and service entrances." The service-entrance measurement therefore calls for a CAT IV instrument with an adequate voltage rating.

   Reference: Fluke: IEC Category Ratings — IEC category ratings

3. 3An industrial enclosure will be installed outdoors where it is exposed to hose-directed water and a corrosive atmosphere. Among these NEMA enclosure types, which provides the specified water and additional corrosion protection?

   1. A.Type 3R
   2. B.Type 4
   3. C.Type 4XCorrect answer: C
   4. D.Type 12

   Explanation: NEMA describes Type 4X as providing protection against "hose directed water" and "an additional level of protection against corrosion". Type 4 addresses hose-directed water without the additional corrosion rating; Type 3R and Type 12 do not provide this combination.

   Reference: National Electrical Manufacturers Association: NEMA Enclosure Types — Type 4X

4. 4A conventional three-wire motor starter must remain energized after its momentary START button is released. In the control circuit, across which device is its maintaining auxiliary contact connected?

   1. A.The START pushbutton contactCorrect answer: A
   2. B.The STOP pushbutton contact
   3. C.The overload relay contact
   4. D.The contactor coil terminals

   Explanation: The BC guide states: "Maintaining contacts are in parallel with START buttons." The auxiliary contact therefore provides a holding path across START after the button returns to normal.

   Reference: BC Construction Electrician Apprenticeship: Magnetic Motor Controls — Learning Task 3, schematic principles, page 30

5. 5An infrared illuminator is aimed at a surveillance scene, but its beam is much wider than the camera's field of view. What effect should the electrician expect from this beam mismatch?

   1. A.Reduced forward reach and extra illumination outside the sceneCorrect answer: A
   2. B.Greater forward reach and extra illumination outside the scene
   3. C.Reduced forward reach and less illumination outside the scene
   4. D.Greater forward reach and less illumination outside the scene

   Explanation: Axis states: "a too widely illuminated area entails both a reduced light reach in the forward direction, and the unnecessary illumination of objects that are outside the area of interest." The other choices reverse one or both effects.

   Reference: IR in Surveillance — Section 4.3, Standalone illuminators, page 9

6. 6A linear pressure transmitter sends 4 mA at 0 kPa and 20 mA at 200 kPa. What loop current should the electrician expect at 50 kPa?

   1. A.4 mA
   2. B.8 mACorrect answer: B
   3. C.10 mA
   4. D.12 mA

   Explanation: NI states that "4 mA represents the zero percent signal and 20 mA represents the 100 percent signal." Here 50/200 = 0.25 of span; 4 + 0.25 × (20 − 4) = 8 mA. Four mA ignores the applied pressure, 10 mA applies 50% of the full-scale current instead of the live-zero span, and 12 mA represents the midpoint of the range.

   Reference: Current Measurements: How-To Guide — 4–20 mA current loop

7. 7An industrial electrician reviews an arc flash assessment for a switchboard. In the CCOHS explanation of the arc flash boundary, what incident energy at the skin is used to represent the onset of a second-degree burn?

   1. A.1.2 cal/cm²Correct answer: A
   2. B.4.0 cal/cm²
   3. C.8.0 cal/cm²
   4. D.25.0 cal/cm²

   Explanation: CCOHS states: "It is assumed that a second-degree burn occurs when the incident energy received by the skin equals 5 J/cm2 (1.2 cal/cm2)." The stated incident energy is therefore 1.2 cal/cm².

   Reference: CCOHS: Arc Flash — What are approach boundaries?

8. 8An electrician checks the phase relationships of a balanced three-phase supply feeding an industrial service. What electrical angle separates successive phase voltages?

   1. A.60 degrees
   2. B.90 degrees
   3. C.120 degreesCorrect answer: C
   4. D.180 degrees

   Explanation: Fluke describes three-phase power as having "each phase ac signal 120 electrical degrees apart." The successive phase voltages are therefore separated by 120 electrical degrees.

   Reference: Fluke: Single-Phase vs. Three-Phase Power — Single-phase and three-phase power supplies

9. 9An electrician plans a power-cable pull around a bend using one of four guide sheaves. If pulling tension is the same and all four sheaves are otherwise suitable, which radius produces the lowest cable sidewall pressure?

   1. A.150 mm radius
   2. B.200 mm radius
   3. C.250 mm radius
   4. D.300 mm radiusCorrect answer: D

   Explanation: Southwire states, "Sidewall pressure can be reduced by using a large radius sheave." With equal pulling tension, the 300 mm radius gives the lowest pressure of the four; the 150, 200 and 250 mm radii are progressively tighter.

   Reference: Southwire: Power Cable Installation Guide — Chapter 7, Rollers and Sheaves

10. 10A reversing contactor changes the motor supply phase sequence from A-B-C. Which sequence reverses a three-phase motor's rotation?

    1. A.A-B-C
    2. B.B-C-A
    3. C.C-A-B
    4. D.A-C-BCorrect answer: D

    Explanation: The BC trades guide states that reversing the phase sequence requires "interchange any two of the three line leads". A-C-B interchanges B and C. A-B-C, B-C-A and C-A-B preserve the original cyclic order.

    Reference: BC Construction Electrician Apprenticeship: Magnetic Motor Controls — Learning Task 6, reversing magnetic starters, page 47