California Electrical Contractor (C-10) License Practice Exam

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• In rocky ground, what is an approved method for installing a temporary ground rod?
• What is the maximum amount of current that an appliance on a 20-amp branch circuit should draw?
• What are the symptoms of shock?
• What does ampacity measure?
• 65 street lights are fed by a 2275-volt series circuit. What is the voltage across each light?
• What is the maximum amperage permitted for No. 1 THW wire?
• What is a GFCI outlet designed to protect against?
• Which method ensures electrical continuity at a service entrance?
• What is one primary function of a conduit?
• Why is it recommended to leave a proper length of Romex tail?
• What is the safe distance requirement from overhead electrical lines energized between 600 V and 50,000 V for boom-type lifting equipment?
• If a co-worker suffers a deep, bleeding gash to the head, what should you do?
• Who issues the electrical permit for a project?
• What device is used to measure large values of alternating current?
• In knob-and-tube wiring, what is the minimum clearance requirement between conductors?
• What is the primary purpose of using a Ground Fault Circuit Interruptor (GFCI) for portable power tools?
• What document authorizes changes in scope, price, or schedule?
• What is the current output of a 75 kVA, 480 V, three-phase transformer?
• Which factor has the least impact on transformer efficiency?
• Which dwelling-unit outlets require GFCI protection?
• What is a service disconnect?
• What is a subpanel?
• Which of the following is NOT a common type of conduit used in electrical installations?
• The rated ampacity of an individual outlet should be how it compares to the amperage rating of the branch circuit?
• A change order is used to modify which aspects of a project?
• Which items should be included in an electrical estimate?
• Distinguish between a neutral conductor and an equipment grounding conductor.
• What impact do Title 24 energy standards have on electrical installations?
• In California, prevailing wage requirements apply to which type of projects?
• The symbol represents a:
• What is the purpose of using circuit breakers in electrical systems?
• One million watts is equivalent to how many megawatts?
• Which size screws are required for mounting light fixtures?
• What is required when employees are working on energized equipment?
• Which statement best describes a feeder in an electrical system?
• What is the role of Cal/OSHA on electrical job sites?
• If a circuit draws 60 amps from a 480 V source with a power factor of 90%, what would be the output in kilowatts?
• If the ampacity rating is exceeded, what is the most likely hazard?
• What type of voltage is required in a commercial building housing business machines and computers?
• If plans call for metal flexible tubing but the owners want to save money, what alternative can you use while still meeting NEC codes?
• What factor is critical when calculating the kW of a transformer?
• If a colleague is found unconscious on a high-tension wire, what is the safest way to help them?
• What is the difference between a short circuit and an overload condition?
• Which agency enforces safety requirements for electrical workers in California?
• What is the required minimum grounding electrode conductor size for a 200-amp residential service?
• A 5 kW appliance is used for 5 hours. At $0.014 per kWh, what is the cost of running the appliance?
• Which California license classification covers electrical contracting work?
• Why is tagging and labeling circuits important?
• What material is commonly used for electric service wire insulation in underground applications?
• How many 1250-watt appliances can be used on a 50-amp, 120-volt branch circuit?
• What is the minimum size wire that can be used for a 9kW range?
• The resistance measurement of which equipment is critical for assessing grounding?
• What is box fill?
• Which statement best describes the relationship between the NEC and California amendments?
• The red lead wire on a heating cable indicates what voltage level?
• According to Cal/OSHA, what is the minimum height for scaffolds to require guardrails?
• What does the term “overcurrent” refer to in electrical systems?
• What is the kW rating of a transformer that supplies 480 V and 40 A?
• What is the minimum clear working space required in front of a 480 V panel facing exposed live parts?
• What does the term "grounding electrode" refer to in electrical systems?
• What is the maximum length of the ground return path in flexible metal conduit (FMT)?
• What is the greatest difference in potential between any two conductors of a circuit called?
• What is the purpose of a ground fault circuit interrupter (GFCI)?
• Where is the panel schedule typically located and what information does it list?
• What is a common use case for a phase-directional meter in electrical applications?
• What is the minimum number of receptacles required at each patient bed location in critical care areas of healthcare facilities?
• When solving for "I" (current) in a transformer drawing, what is the result if the current measures 200 amps?
• What is overcurrent protection and where is it used?
• What does it mean to backfeed a panel, and when is it used?
• Which tool is typically used to measure electrical current in a circuit?
• After installing a new A/C how would you test it?
• How far should a junction box be set back in a concrete wall?
• What is the standard calculation for general lighting load in residential areas?
• What is the resistance of a 110 W lamp connected to a 220 V line?
• What tool is best used for bending conduit?
• Why is proper documentation and recordkeeping essential in electrical contracting?
• What type of connector can be used to ensure a reliable electrical connection at a service entrance?
• On a service call to a machine shop where an employee was shocked by a piece of equipment, what would you not need to do?
• Which method is acceptable for equipment grounding?
• An ammeter must be connected in what manner with the load?
• What is the minimum clear working space in front of a 480 V panel against a grounded wall?
• How many No. 12 conductors can fit in a 4-11/16" box with a volume of 42 cubic inches?
• What is the smallest wire size permitted for general wiring?
• Which of the following best describes a feeder in an electrical system?
• What is the purpose of a transformer in an electrical system?
• What is lockout/tagout and why is it used?
• Which statement best describes the service disconnect?
• What type of wire is best suited for outdoor use?
• What is the minimum allowable height for overhead community antenna system coaxial lines above swimming pools?
• What is the minimum working clearance from an electrical panel under 600 V?
• What is the purpose of granular desiccants in cable insulation?
• Which of the following methods is commonly used to solidly ground electrical equipment?
• What is necessary for proper equipment grounding?
• If the plumber accidentally cuts installed wires, to whom should you report the problem?
• What is the minimum clearance required for service drops over public areas where truck traffic is present?
• What is a grounding electrode system and name common components?
• Which of the following is a typical color used for hot conductors in a 120/240V system?
• Which type of insulation is required for underground applications?
• If a fixed electric space heater has a demand factor of 65%, what percent should be added to the heating circuit if the central air-conditioning unit has a demand factor of 100%?
• In a typical electrical system, what is a feeder?
• Which statement best describes weatherproof enclosures in outdoor wiring?
• What size screws are typically required to fasten a plug receptacle to a box?
• Which statement best describes the NEC 110.26 working space requirement around electrical equipment?
• Which statement is NOT a common component of a grounding electrode system?
• What is voltage drop and why is it important?
• If four 1.5-volt batteries are wired in series, what is the resulting voltage?
• In NEC terms, what is a continuous load?
• In residential wiring, what is the standard voltage used?
• Service conductors must maintain a clearance of at least how many feet from windows?
• When connecting a main panel to a sub-panel, what is the smallest conductor size that can be run in parallel?
• Why is conductor temperature rating important (e.g., THHN at 90C)?
• Voltage drop in wire is a function of which of the following?
• When compared to copper, aluminum conductors are generally:
• For voltage exceeding 300 volts, what is the minimum clearance requirement for service-drop conductors from flat roof structures?
• Which of the following are factors that influence conductor ampacity?
• How is the power rating of a three-phase transformer calculated?
• Which statement best describes the minimum working space in front of electrical equipment?
• What type of cable has an internal bonding strip of copper or aluminum in contact with armor for its entire length?
• What is a multi-wire branch circuit (MWBC) and what is required for it?
• If a bank has two single-phase transformers, one rated at 20 kVA and the other at 15 kVA, what would be their total capacity in kVA?
• For an electric appliance with a 17.5 A load, the overcurrent device must not exceed what amperage?
• What is the best instrument to measure the current in a high-voltage supply line?
• What is the appropriate treatment for a burn at a jobsite?
• Of the following subtrades, which one must yield in the case of a dispute?
• In residential wiring, what is the purpose of the neutral wire?
• What is the recommended length of Romex tail to leave in a box?
• Ampacity is defined as:
• Which instrument is used to check pump motor rotation?
• Which of the following is the largest wire size option available?
• A fixture that weighs more than ______ must be supported independently of an outlet box.
• What is the maximum distance to an outlet from any point along the wall behind a kitchen counter?
• What is the purpose of an AFCI?
• Which of the following materials is not corrosive?
• Where should a sub-panel be installed in a warehouse with a paint spray area that has a lot of over spray?
• What does the National Electrical Code (NEC) primarily regulate?
• During field inspections, which item is typically verified?
• What tool is specifically designed for stripping armored cable?
• What is the smallest conductor permitted for general wiring made of copper?
• What are conduit fill and its purpose?
• Which component is crucial for the safe operation of electrical appliances in a residence?
• Outdoor receptacles and GFCI protection: which statement is true?
• Which of the following can NOT be used to measure ground resistance?
• Which type of installation is not typically associated with residential buildings?
• How does a change order affect the contract?
• What is the primary function of a circuit breaker?
• What is a panel schedule and what information does it contain?
• For branch circuit conductors supplying continuous loads, by how much must they be sized based on normal ampacity?
• Which of the following is not a factor influencing ampacity?
• A 12-volt direct current, 13-watt fluorescent light is controlled by a photocell. How many watt-hours are consumed by the light on an average day if it is on for 12 hours?
• What is the minimum size for overhead service entrance cable allowed?
• Which code governs electrical installations in California and how does the NEC relate to it?
• What is the smallest size grounding conductor permitted for service entrance?
• What is the maximum amperage permitted for No. 8 THWN conductor?
• What is the maximum permitted distance between convenience outlets in kitchens?
• Which NEC article covers grounding and bonding?
• What is the amperage rating for No. 1 aluminum THW?
• What is a requirement for solar panels and metal equipment in roof-mounted PV systems?
• How thick is one mil?
• What is the maximum length of flexible metal conduit that can be used without a ground?
• What are common outdoor wiring requirements?
• Which item is not typically included in final project documentation?
• In three-phase systems, what is the formula to calculate current from kVA and voltage?
• What is the typical voltage rating for residential electrical systems in the United States?
• For a house with all-electric appliances and a size of approximately 2300 sq ft, what is the minimum size for the ground conductor?
• What is the allowable voltage drop for a branch circuit connected to a heater?
• If an electrical sub-contractor discovers a conflict in the plans, whom should they contact?
• Among the listed metals, which one is the best conductor of electricity?
• Which instrument is used to test the resistance of wire insulation?
• What is the primary code reference used by electricians for installation requirements?
• If a No. 8 copper conductor is rated at 50 amps, what is the equivalent aluminum wire size?
• Which of the following must be considered when selecting wire for an electrical installation?
• Which of the following instruments should not be used on a live circuit?
• Which items demonstrate code compliance after project completion?
• The shunt connected parallel to the leads of an ammeter is called a(n):
• How quickly must Cal/OSHA investigate after a major accident?
• What term describes the maximum current a conductor can safely carry under specified conditions?
• Which of the following is an example of inductive dielectric heating?
• What is the proper color designation for 120-volt heating cables?
• Which statement best describes the grounding electrode system’s role?
• What should an electrical contractor do if a service drop enters and exits a building en route to another building?
• What is a meter main and where is it used?
• What is the difference between plan drawings and project specifications?
• What must a contractor obtain before starting electrical work on a project?
• Where may you use nonmetallic-sheathed cable?
• What is an Erickson coupling used for?
• What does the symbol between A and B in a circuit diagram typically represent?
• Why are permits important in electrical projects?
• What term refers to the conductors and equipment that connect the electrical supply system to the wiring system?
• What is the minimum permitted size fixture wire?
• What is the purpose of a GFCI?
• What is the total resistance of three 12-ohm resistors wired in parallel?
• If a contractor identifies a major code violation in approved plans, what is the required action?
• What should be included in as-built drawings?
• What is the primary purpose of bonding and grounding in electrical installations?
• Which type of electrical box cannot be threaded in the field?
• What is the main purpose of installing a temporary ground rod in electrical work?
• What is the maximum voltage allowed for a plug fuse?
• Which of the following actions is not acceptable when investigating an energized circuit?
• Which component typically protects electrical circuits from overloads and short circuits?
• Plan reading involves what main activity?
• Using Ohm's law, which formula is used to calculate resistance?
• What is the minimum number of feet a worker must be from an overhead high-voltage line?
• What is a key safety consideration for installations in commercial areas?
• Which NEC article covers motors and motor circuits?
• In a 120/240V electrical system, which colors are typically used to denote hot, neutral, and ground conductors?
• When flexibility is not required, AC cable should be stapled or strapped how far from a box?
• What requirement must portable power tools meet at a job site?
• Which statement best distinguishes a circuit from a branch circuit?
• What does an electrical transformer do?
• Which NEC article covers general wiring methods?
• What is a mechanics lien?
• In electrical wiring, what does a straight line often represent in diagrams?
• What should you fill a conduit with to prevent gas from escaping?
• In which application would a 50 kVA transformer typically be used?
• What is the purpose of the Contractor's License Bond in California?
• What is bonding and why is it necessary?
• What is the maximum distance from a box you should install a pipe strap for EMT?
• What is the maximum amperage that No. 10 THW wire can carry?
• Which type of electrical current is commonly used in residential wiring?
• What tool is commonly used to measure electrical current in a circuit?
• Box fill: why is it important to calculate it?
• Which entity may file a mechanics lien?
• What is the typical sequence of permit-related steps for electrical work?
• What do you not take into consideration when doing load demand calculations?
• In the permit process, what is the purpose of plan submittal?
• Which item is not addressed by Title 24 energy standards?
• What is the minimum clearance required for service drops over residential properties and driveways where the voltage is limited to 300 volts to ground?
• What is considered unsafe for using a step ladder in terms of height?