Isa Utility Specialist (Ch. 5 - Electrical Knowledge) Exam Questions With Verified Solutions Latest Update 2026

ISA UTILITY SPECIALIST (CH. 5 - ELECTRICAL KNOWLEDGE) EXAM QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026 What is a volt? - Answers a unit of electrical force Electrical resistance determines how much __________ is required to move electricity along a conductor and is measured in __________. - Answers energy; ohms A conductor carrying more than __________ volts would be considered a NERC line. - Answers 200,000 2 examples of protective equipment: - Answers circuit breakers lightning receptors An energized wire or conductor in a circuit is also known as a __________. - Answers phase True or False? Guy wires are intended to help support poles but may become unintentionally energized. - Answers true A __________ is similar to a fuse or cutout, but it resets after a predetermined time period. - Answers re-closer Minimum working distances for qualified line-clearance arborists are specified in the __________ safety standard. - Answers ANSI Z133 When installing underground conductors, __________ should be used in tree root protection zones. - Answers tunneling Distribution transformers typically __________ primary circuit voltage for the end user. - Answers reduce Amp: - Answers the measure of electrical current Service lines and secondary distribution lines usually carry voltage between __________-__________ volts. - Answers 120-240 When a tree contacts one electrical conductor, it may cause a __________-to-__________ fault. - Answers phase-ground fault The minimum approach distance for non-qualified line clearance personnel from energized conductors 50 kV and less: - Answers 10 feet The condition that allows electricity to flow from one object to another is called: - Answers potential What is a Watt? - Answers a measure of electrical power A phase-to-phase fault occurs when there is contact between: - Answers two or more energized conductors If the coating on a weatherproofed conductor falls off, the conductor will often __________. - Answers deteriorate Ohm's Law describes the relationship between: - Answers voltage, current, & resistance Formula for Ohm's Law: - Answers Volts = Amps x Resistance (V = I x R) Formula for power: - Answers Power = Volts x Current (P = V x I) A __________ is another name for a generating plant, and is the source of most power in the U.S. The most common sources for this power are __________ __________, __________ or __________ turbines, & __________ __________. - Answers powerhouse; fossil fuels, wind or water turbines, & nuclear reactors Tree-caused physical damage to conductors, electrical equipment, and/or supporting structures is an example of a __________ failure. - Answers mechanical The most common type of wire used today is an aluminum wire with a steel reinforced core. This wire is known as: - Answers ACSR (Aluminum Conductor Steel-core Reinforced) Voltage Ranges: Extra-high transmission lines: __________-__________ volts Transmission lines: __________-__________ volts Subtransmission lines: __________-__________ volts Distribution lines: __________-__________ volts - Answers 345,000-765,000 volts 115,000-230,000 volts 23,000-115,000 volts 2,400-23,000 volts The voltage between the feet of a person standing near an energized, grounded object: - Answers step-potential Soil removed during trenching should be stored where? - Answers on the side of the trench that is away from the tree Circuits that carry the highest voltage to other parts of the distribution network are called: - Answers primary circuits __________ lines come off of primary circuits, but don't extend directly to a customer's property. - Answers secondary A device that can store energy & is used to either boost voltage or provide power factor correction: - Answers capacitor The potential between live conductors or between live & nuetral conductors is known as __________-to-__________ potential. - Answers phase-to-phase What is a phase? - Answers an energized wire Protective equipment is designed to shield the system from: - Answers faults, short circuits, & current surges The potential between live conductors & the ground is known as __________-to-__________ potential. - Answers phase-to-ground __________ __________ are designed to redirect electrical surges to the ground instead of allowing them to continue down the circuit. - Answers lightning arrestors A tree or branch coming into contact with an energized conductor, causing a short circuit is an example of an __________ failure. - Answers electrical Two types of failure modes: - Answers mechanical & electrical The potential between live conductors & the neutral wire is known as __________-to-__________ potential. - Answers phase-to-neutral Circuits that feed electricity to other parts of the distribution network are called: - Answers feeder circuits Amps in a conductor that are larger than those for which it is rated: - Answers overcurrent A wire connection between energized conductors & other electrical equipment (e.g. transformers): - Answers tap In electric generation, the number of magnet revolutions per second: - Answers Hertz Repeated momentary interruptions in the same place due to the same cause: - Answers intermittent faults A __________ is a bypass of an intended conducting path. The current bypassing the designed conducting path is called a __________ __________. - Answers fault; short circuit - VM should be performed around ungrounded supply conductors - Vegetation that may damage ungrounded conductors should be pruned or removed (note: it is not practical to prevent all tree-conductor contacts on overhead lines) - Where pruning/removal aren't practical, the tree & conductor should be separated with suitable materials - VM should be performed at line crossings, railroad/highway crossings, navigable waterways, etc. (note: vegetation should be particularly maintained within these spans & the adjacent spans on each side) These rules come from: - Answers National Electrical Safety Code (NESC) Rule 218 Transmission circuit breakers operate in response to abnormally high __________, abnormally low __________, & unequal __________. - Answers amperage; voltage; current In response to the 2003 blackout, NERC developed a standard that requires North American utilities to have systematic programs that effectively prevent outages on the bulk transmission system. This standard is called: - Answers FAC-003 An energized conductor or wire in a circuit is called a __________. - Answers phase (identified as ∅) The value which if exceeded could expose a widespread area to instability or cascading outages: - Answers interconnection reliability operating limit (IROL)