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Electrician 2017 Exam
Question 1. Which of the following best defines voltage in an electrical circuit? A) The rate at which energy is transferred B) The potential difference between two points C) The flow of electrons through a conductor D) The opposition to current flow Answer: B Explanation: Voltage is the potential difference between two points, driving current through a circuit. Question 2. In a DC circuit, the current flows: A) Alternating directions B) Only in one direction C) Randomly D) Varies periodically Answer: B Explanation: Direct current (DC) flows in one direction only, unlike AC which alternates direction. Question 3. Which waveform is characteristic of AC power supply? A) Square wave B) Sine wave C) Triangle wave D) Sawtooth wave Answer: B Explanation: AC power is typically characterized by a sine wave, representing smooth periodic oscillation. Question 4. Capacitance in an electrical circuit is the ability to:
Electrician 2017 Exam
A) Store energy in a magnetic field B) Store energy in an electric field C) Oppose changes in current D) Resist voltage Answer: B Explanation: Capacitors store energy in an electric field between their plates. Question 5. Inductance is the property of a circuit element that opposes changes in: A) Voltage B) Resistance C) Current D) Capacitance Answer: C Explanation: Inductance opposes changes in current due to the magnetic field created around the coil. Question 6. Magnetism and electromagnetism are related because: A) Moving charges produce magnetic fields B) Magnetic fields create static electricity C) Magnetism only occurs in ferromagnetic materials D) They are unrelated phenomena Answer: A Explanation: Moving electric charges produce magnetic fields, illustrating the connection between electricity and magnetism. Question 7. Ohm’s Law states that voltage across a resistor is equal to: A) Current divided by resistance B) Resistance times current
Electrician 2017 Exam
Answer: B Explanation: Kirchhoff’s Voltage Law states that the sum of all voltage drops around a closed loop equals the supply voltage. Question 11. In a parallel circuit, the total current is: A) The sum of currents through each branch B) Equal to the current through the branch with the highest resistance C) The same as the current through each branch D) Zero Answer: A Explanation: The total current divides among branches, and the sum equals the total current supplied. Question 12. According to Kirchhoff’s Current Law, at a junction point: A) The sum of currents entering equals the sum leaving B) Voltage is constant C) Resistance is minimized D) Power is maximized Answer: A Explanation: Kirchhoff’s Current Law states the algebraic sum of currents entering and leaving a junction is zero. Question 13. A short circuit occurs when: A) Resistance is very high B) Conductors are connected with negligible resistance, causing high current flow C) The circuit is open D) The circuit is properly grounded Answer: B
Electrician 2017 Exam
Explanation: A short circuit provides a low-resistance path, causing potentially dangerous high currents. Question 14. An open circuit is characterized by: A) Continuous current flow B) No current flow due to a break in the circuit C) Excessive current D) Ground fault condition Answer: B Explanation: An open circuit has a break preventing current flow. Question 15. In a three-phase system, a balanced load means: A) All phases carry equal currents and voltages B) One phase carries all the load C) The system is ungrounded D) The system is single-phase Answer: A Explanation: Balanced three-phase systems have equal current and voltage magnitudes on all phases. Question 16. Which of the following hazards is associated with arc flash? A) Burns and blindness B) Electrocution only C) Mechanical injury D) Chemical burns Answer: A Explanation: Arc flash can cause severe burns, blindness, and other injuries due to intense heat and light.
Electrician 2017 Exam
B) A conductor connected to a live source C) An uninsulated conductor D) A conductor used only in industrial systems Answer: A Explanation: A grounded conductor (neutral) is intentionally connected to ground to complete electrical circuits safely. Question 21. Article 110 of the NEC requires that electrical equipment be: A) Approved and suitable for use B) As old as the building C) Installed only outdoors D) Used without grounding Answer: A Explanation: Equipment must be approved by recognized testing agencies and suitable for the intended use. Question 22. Working space about electrical equipment must be provided to: A) Allow safe operation and maintenance B) Prevent theft C) Reduce electromagnetic interference D) Increase electrical resistance Answer: A Explanation: Adequate working space ensures safe operation and maintenance of electrical equipment. Question 23. Guarding of live parts is necessary to: A) Protect personnel from accidental contact B) Prevent electromagnetic interference
Electrician 2017 Exam
C) Reduce circuit noise D) Improve heat dissipation Answer: A Explanation: Guarding prevents accidental contact with energized parts, reducing shock hazards. Question 24. The purpose of electrical markings and labels is to: A) Identify equipment and voltages B) Decorate the installation C) Increase resistance D) Reduce electromagnetic emissions Answer: A Explanation: Markings help identify equipment, voltages, and hazards for safe operation. Question 25. A transfer switch is used to: A) Connect loads to different power sources B) Increase voltage C) Reduce current D) Isolate circuits permanently Answer: A Explanation: Transfer switches enable switching between power sources, such as utility and generator. Question 26. Grounded conductors are connected to: A) Grounding system B) Live conductors C) Neutral only in commercial systems D) Only in residential systems
Electrician 2017 Exam
Question 30. Bonding of metal parts ensures: A) Electrical continuity and safety B) Increased resistance C) Reduced electromagnetic interference D) Improved insulation Answer: A Explanation: Bonding connects metal parts to grounding systems to prevent shock hazards. Question 31. A grounding conductor is typically sized based on: A) The overcurrent device rating B) The length of the conductor C) The voltage of the system D) The type of equipment Answer: A Explanation: Grounding conductors are sized according to the overcurrent protection device to ensure safety. Question 32. Conductor insulation types such as THHN and XHHW are selected based on: A) Temperature ratings and environment B) Color preference C) Cost only D) Length of the circuit Answer: A Explanation: Insulation types are chosen for their temperature ratings and suitability for specific environments.
Electrician 2017 Exam
Question 33. Which article covers nonmetallic-sheathed cable (Type NM)? A) Article 334 B) Article 310 C) Article 376 D) Article 430 Answer: A Explanation: Article 334 details requirements for nonmetallic-sheathed cables like NM cables. Question 34. Rigid metal conduit (RMC) is primarily used for: A) Heavy-duty indoor and outdoor applications B) Temporary wiring C) Flexible connections only D) Low-voltage installations Answer: A Explanation: RMC provides durable, sealed protection suitable for various environments. Question 35. Metal-clad cable (Type MC) differs from flexible conduit because it: A) Is a factory-assembled cable with metallic armor B) Is made of nonmetallic materials C) Has no grounding conductors D) Cannot be installed outdoors Answer: A Explanation: Type MC is a cable with metallic armor, offering protection and ease of installation. Question 36. An example of a wiring method permitted for outdoor use includes: A) Underground conduit
Electrician 2017 Exam
D) 6 AWG
Answer: C Explanation: NEC tables specify minimum sizes; for 100A circuits, 12 AWG is generally acceptable unless otherwise specified. Question 40. In a three-phase system, unbalanced load causes: A) Unequal current in the phases B) Equal voltage in all phases C) No effect on system operation D) Reduced power consumption Answer: A Explanation: Unbalanced loads cause unequal currents, potentially leading to system inefficiency. Question 41. Which of the following is a primary hazard associated with arc blast? A) Severe pressure wave and flying debris B) Mild shock C) Chemical burns D) Noise pollution Answer: A Explanation: Arc blast involves a high-pressure wave and flying debris, causing serious injury. Question 42. Lockout/tagout procedures should be performed: A) Before servicing or repairing electrical equipment B) During normal operation C) Only in emergency situations D) After completing repairs Answer: A
Electrician 2017 Exam
Explanation: Lockout/tagout prevents accidental energization during maintenance. Question 43. The main purpose of a GFCI receptacle is to: A) Protect against ground-faults and reduce shock B) Increase circuit capacity C) Protect against overcurrent D) Provide a continuous power supply Answer: A Explanation: GFCI detects ground-faults and quickly disconnects power to prevent shock. Question 44. The purpose of a disconnecting means for a motor is to: A) Safely disconnect power for maintenance B) Increase motor speed C) Reduce motor noise D) Improve efficiency Answer: A Explanation: Disconnecting means allow safe disconnection of power for servicing. Question 45. Overcurrent protection for a motor circuit must be rated to protect: A) The conductors and motor from overload and short circuit B) Only the motor C) The control panel only D) The power supply only Answer: A Explanation: Proper overcurrent protection safeguards both conductors and the motor itself.
Electrician 2017 Exam
B) No grounding required C) Continuous connection regardless of maintenance D) High resistance connections Answer: A Explanation: Proper wiring includes ventilation and overcurrent protection to ensure safety. Question 50. An example of a flexible cord suitable for portable tools is: A) SO cable B) Type NM cable C) Type MC cable D) Type UF cable Answer: A Explanation: SO (-service entrance) cables are flexible, suitable for portable appliances and tools. Question 51. Which wiring method is most suitable for a commercial control panel? A) Rigid metal conduit (RMC) B) Nonmetallic-sheathed cable (Type NM) C) Surface nonmetallic raceway D) Open wiring on insulators Answer: A Explanation: RMC provides durable protection suitable for control panels in commercial settings. Question 52. The minimum clearance for overhead service drops above driveways is typically: A) 10 feet B) 4 feet C) 15 feet
Electrician 2017 Exam
D) 12 inches Answer: A Explanation: NEC requires a minimum clearance of 10 feet above driveways for safety. Question 53. Which article addresses requirements for circuit breakers? A) Article 240 B) Article 430 C) Article 250 D) Article 404 Answer: A Explanation: Article 240 covers overcurrent protection devices, including circuit breakers. Question 54. When selecting wire sizes for branch circuits, the most critical factor is: A) Ampacity ratings B) Length of the wire C) Color coding D) Cost Answer: A Explanation: Ampacity determines the maximum current the wire can safely carry. Question 55. An equipment grounding conductor must be: A) At least as large as the supply conductors or as specified B) Always 14 AWG C) Grounded only at the service entrance D) Uninsulated Answer: A
Electrician 2017 Exam
Question 59. The purpose of a wiring method in NEC is to: A) Ensure safe and reliable electrical connections B) Make wiring faster C) Improve electrical noise immunity D) Reduce cost only Answer: A Explanation: Wiring methods are designed for safety, durability, and code compliance. Question 60. Which of the following is a recognized grounding electrode? A) Metal water pipe B) Aluminum conduit C) Plastic pipe D) Wooden pole Answer: A Explanation: Metal water pipes are recognized grounding electrodes when properly installed. Question 61. In a three-phase system, the phase sequence refers to: A) The order in which phases reach their maximum voltage B) The total resistance of the system C) The number of circuits in the system D) The frequency of the power supply Answer: A Explanation: Phase sequence indicates the order of phase voltage peaks, crucial for proper operation. Question 62. An overcurrent device rated at 125% of the motor full load current is used to:
Electrician 2017 Exam
A) Protect against motor overloads B) Enable higher starting torque C) Reduce energy consumption D) Increase motor speed Answer: A Explanation: Overcurrent ratings are set to protect against overloads, preventing motor damage. Question 63. The main purpose of a switch in a motor circuit is to: A) Disconnect power for maintenance B) Increase motor torque C) Reduce voltage D) Protect against short circuits Answer: A Explanation: Switches provide a means to disconnect power safely during servicing. Question 64. The required clearance around electrical equipment to prevent accidental contact is specified in: A) NEC Article 110 B) NEC Article 250 C) NEC Article 240 D) NEC Article 300 Answer: A Explanation: Article 110 covers general requirements, including working space and clearances. Question 65. Which wiring method uses nonmetallic raceways or conduit for surface mounting? A) Surface metallic raceways B) Rigid metal conduit
