1.
The clearance between conductor line on an overhead line is determined by the :
Correct Answer
B. Voltage in the Line
Explanation
The clearance between conductor lines on an overhead line is determined by the voltage in the line. Higher voltages require larger clearances to prevent electrical arcing and maintain safety. This is because higher voltages can cause the air surrounding the conductors to break down and conduct electricity, leading to short circuits or electrical faults. Therefore, the voltage in the line directly affects the required clearance between conductor lines.
2.
What is the voltage across the high leg in a delta-connected transformer secondary system with a nominal rating of 120 240 volts?
Correct Answer
D. 208
Explanation
In a 120/240V delta-connected transformer secondary, the high-leg voltage should be approximately √3​ times the phase voltage, which means around 208 volts. This is due to the delta connection's characteristics, where the line-to-ground voltage on the high leg is higher than the other two phases.
3.
In order to obtain the maximum secondary voltage from the transformer, the action to be taken to set the tap changer at
Correct Answer
A. 100%
Explanation
Setting the tap changer at 100% means that the transformer is operating at its maximum secondary voltage. This allows for the highest possible voltage output from the transformer. The other options, such as 104.5%, 95.9%, and 95.5%, would result in lower secondary voltages. Therefore, setting the tap changer at 100% is the correct action to obtain the maximum secondary voltage from the transformer.
4.
Two energized three phase liners are being phase test with a volt meter. When non corresponding phases are connected through the meter, the reading should be
Correct Answer
D. pHase to pHase voltage
Explanation
When non-corresponding phases are connected through the meter, the reading should be phase to phase voltage. This means that the volt meter will measure the voltage difference between two different phases of the three-phase system. The voltage reading will not be zero because there is a potential difference between the two phases, and it will not be phase to ground voltage or phase to neutral voltage because these readings are specific to the connection between a phase and ground or neutral, not between two different phases.
5.
If loaf break equipment is not available on a 150 kva transformer bank the first action to take if it becomes necessary to open the bank is to
Correct Answer
A. Open the primary disconnects
Explanation
The first action to take if it becomes necessary to open the bank is to open the primary disconnects. This is because opening the primary disconnects will cut off the power supply to the transformer bank, ensuring the safety of anyone working on or around the equipment. Grounding the secondaries, using consumer service equipment to remove the load, or setting the tap changer to 100% are not the first steps to be taken in this situation.
6.
One disadvantage of a 3 phase transformer compared to three single phase transformers is :
Correct Answer
B. Higher initial cost
Explanation
The disadvantage of a 3 phase transformer compared to three single phase transformers is the higher initial cost. This means that the initial investment required to purchase and install a 3 phase transformer is greater than that of three separate single phase transformers.
7.
You wish to determine the peak load on a transformer secondary what instrument is required?
Correct Answer(s)
B. Maxl meter
D. Clip on ammeter
Explanation
To determine the peak load on a transformer secondary, two instruments are required: a maxl meter and a clip on ammeter. A maxl meter is used to measure the maximum current or load that the transformer is experiencing at any given time. On the other hand, a clip on ammeter is used to measure the actual current flowing through the secondary winding of the transformer. By using these two instruments together, the peak load on the transformer secondary can be accurately determined.
8.
If two primary transformer fuses in an underground three-phase star-connected transformer bank are blown, the potential at the star point would be:
Correct Answer
A. 50%
Explanation
If two primary transformer fuses are blown in an underground three-phase star connected transformer bank, it means that only one of the three primary windings is receiving power. In a star connection, the voltage at the star point is the average of the voltages at the three phase points. Since only one phase is receiving power, the potential at the star point would be 50% of the normal voltage. Therefore, the correct answer is 50%.
9.
What is the first step taken when paraleling two single phase transformers
Correct Answer
B. Ascertain if primary pHase is the same
Explanation
The first step taken when paralleling two single phase transformers is to ascertain if the primary phase is the same. This is important because if the primary phases are not the same, it can cause phase imbalance and lead to issues in the parallel operation of the transformers. Therefore, it is necessary to ensure that the primary phases are in sync before proceeding with the parallel connection.
10.
Which of the following is the acceptable method of preventing backfeed from a transformer
Correct Answer
B. Disconnect secondary risers
Explanation
Disconnecting the secondary risers is an acceptable method of preventing backfeed from a transformer. Backfeed refers to the flow of electricity in the opposite direction than intended, which can be dangerous. By disconnecting the secondary risers, the flow of electricity from the transformer to the customer's electrical equipment is interrupted, preventing any potential backfeed. This ensures that the electricity flows only in the intended direction and reduces the risk of electrical hazards.
11.
The main purpose of a stress relief cone on a 15 kv cable is to
Correct Answer
C. Eliminate mechanical stress on the cable
Explanation
The main purpose of a stress relief cone on a 15 kv cable is to eliminate mechanical stress on the cable. This cone is designed to distribute the stress evenly along the cable termination, reducing the risk of damage or breakage. By eliminating mechanical stress, the stress relief cone helps to ensure the longevity and reliability of the cable.
12.
The normal percentage change between taps on a distrubution transformer is
Correct Answer
B. 4.5%
Explanation
The correct answer is 4.5%. This means that the normal percentage change between taps on a distribution transformer is 4.5%. This indicates that when adjusting the tap settings on the transformer, the change in voltage will typically be around 4.5% of the original voltage.
13.
The primary neutral of a WYE delta bank is grounded, what could be the results
Correct Answer
D. The bank will work normally.
Explanation
If the primary neutral of a WYE delta bank is grounded, it means that the bank is properly connected and functioning as intended. Grounding the neutral helps to maintain system stability and protect against voltage fluctuations. Therefore, the bank will work normally, without any adverse effects such as transformer overload or voltage fluctuations.
14.
Small cracks in the insulators may
Correct Answer
B. Cause arc over
Explanation
Small cracks in the insulators can cause arc over. When the insulators have cracks, it compromises their ability to insulate and contain the electrical current. As a result, the electricity can jump across the cracks, creating an arc over. This can lead to a short circuit or a dangerous electrical discharge, potentially causing damage to the equipment or posing a safety hazard. Therefore, it is crucial to identify and repair these cracks to prevent arc over and maintain the integrity of the electrical system.
15.
A function of a lightning arrestor when serving a power system is to
Correct Answer
B. Act as open circuit during normal conditions
Explanation
A lightning arrestor serves as an open circuit during normal conditions. This means that it does not allow any current to flow through it under normal circumstances. By acting as an open circuit, the lightning arrestor prevents any unwanted current from entering the power system and protects the equipment from damage. It only becomes conductive when a lightning strike occurs, providing a low-resistance path for the lightning current to safely dissipate into the ground.
16.
After lockout a circuit recloser is
Correct Answer
B. Heeds to be reset manually
Explanation
After a lockout, a circuit recloser needs to be reset manually. This means that someone has to manually intervene and reset the circuit recloser in order for it to resume normal operation. The circuit recloser does not close automatically or require the replacement of the recloser coil. Instead, it requires manual intervention to reset it and restore its functionality.
17.
A simple device for limiting fault current is :
Correct Answer
C. OCR
Explanation
The correct answer is OCR, which stands for Overcurrent Relay. An OCR is a simple device used to limit fault current. It works by detecting excessive current in a circuit and quickly interrupting the flow of electricity to prevent damage or hazards. OCRs are commonly used in electrical systems to protect equipment and ensure the safety of the overall system. They are able to sense overcurrent conditions and automatically trip the circuit breaker or disconnect the power supply, effectively limiting the fault current.
18.
A voltage regulator will when additional load is connected to the feeder
Correct Answer
B. Boost the line voltage
Explanation
When additional load is connected to the feeder, a voltage regulator will boost the line voltage. This is because the voltage regulator is designed to maintain a steady voltage level despite changes in load. By increasing the line voltage, the voltage regulator ensures that the connected devices receive the required voltage to operate properly, compensating for the added load.
19.
The percent impedance voltage figure shown on a transformer name plate is taken into consideration when
Correct Answer
A. Connecting low power factor load to the transformer
Explanation
The percent impedance voltage figure shown on a transformer nameplate is taken into consideration when connecting a low power factor load to the transformer because it indicates the ability of the transformer to withstand the reactive power generated by the load. A low power factor load can cause the voltage to drop across the transformer due to the reactive power component, and the percent impedance voltage figure helps determine if the transformer can handle this drop without affecting its performance.
20.
If an ammeter utilizing a current transformer is to be removed while the circuit is energized, the precaution which must be taken is,
Correct Answer
A. Short circuit the secondary of the transformer before removing the ammeter
Explanation
When an ammeter utilizing a current transformer is to be removed while the circuit is energized, the precaution that must be taken is to short circuit the secondary of the transformer before removing the ammeter. This is necessary to prevent any high voltage or current from being induced in the secondary winding of the current transformer, which could potentially damage the ammeter or pose a safety risk. Short circuiting the secondary ensures that any current flowing through the primary winding of the transformer is safely diverted and does not cause any harm.
21.
When removing a voltmeter from a potential transformer the transformer terminals must never be
Correct Answer
B. Open circuited
Explanation
When removing a voltmeter from a potential transformer, it is important to open circuit the transformer terminals. This means that the terminals should be disconnected from any external circuit, leaving them unconnected to anything. This is necessary to prevent any unintended electrical connections or short circuits that could potentially damage the transformer or cause safety hazards.
22.
The best rope for use where die electric strength is required is
Correct Answer
A. Polypropylene
Explanation
Polypropylene is the best rope for use where dielectric strength is required. Dielectric strength refers to the ability of a material to withstand electric stress without breaking down. Polypropylene is a non-conductive material with excellent dielectric properties, making it ideal for applications where electrical insulation is necessary. It has a high resistance to electrical current and can effectively prevent electrical accidents or short circuits. Nylon, manila, and dacron do not possess the same dielectric strength as polypropylene, making them less suitable for such applications.
23.
The correct method of installing u bolt clamps on a wire rope is
Correct Answer
C. U bolts on live end of rope
Explanation
The correct method of installing U-bolt clamps on a wire rope is to place the U-bolts on the live end of the rope. This ensures that the clamps are properly secured to the active part of the rope, preventing any slippage or movement that could compromise the integrity of the connection. Placing the U-bolts on the dead end of the rope would not provide the same level of security and stability.
24.
The first indication of overloading a hook is
Correct Answer
B. A worn spot
Explanation
The first indication of overloading a hook is a worn spot. This means that the hook has been subjected to excessive weight or pressure, causing a specific area to become worn or weakened. This can be visually identified as a spot on the hook where the metal appears thinner or damaged. It serves as a warning sign that the hook may not be able to withstand further loads and should be replaced to prevent potential accidents or failures.
25.
The primary function of a phase rotation meter indicator is to check
Correct Answer
A. Sequence
Explanation
A phase rotation meter indicator is used to check the sequence of the phases in a three-phase electrical system. It helps determine if the phases are in the correct order, which is crucial for the proper functioning and safety of electrical equipment. By checking the sequence, the meter ensures that the phases are balanced and correctly connected, preventing any potential damage or hazards that may occur if the sequence is incorrect.
26.
A feature found on a load break disconnect that is not incorporated in a sectionalizing switch is
Correct Answer
C. Double break contacts
Explanation
A load break disconnect is designed to interrupt the flow of current in a circuit, while a sectionalizing switch is used to isolate sections of a circuit for maintenance or repair. Double break contacts refer to the design of the switch or disconnect, where there are two points of contact that open and close simultaneously. This design provides a more reliable and stable connection, ensuring a complete interruption of current flow when the switch is opened. A lightning arrestor, ground terminal, and arc extinguishing device are all separate components or features that can be incorporated into both load break disconnects and sectionalizing switches.
27.
A rachet lever hoist is usually constructed with the weakest part being the
Correct Answer
D. Upper hook
Explanation
A ratchet lever hoist is designed in such a way that the upper hook is usually the weakest part. This is because the upper hook is responsible for bearing the maximum load during lifting operations. The lower hook, on the other hand, is supported by the chain links and handle, which provide additional strength and stability. Therefore, in order to ensure the overall safety and durability of the hoist, it is important to construct the upper hook with the necessary strength and reliability.
28.
The factors that determine the performance of a fuse are
Correct Answer
B. Current and time
Explanation
The performance of a fuse is determined by the current flowing through it and the amount of time it takes for the fuse to blow. When the current exceeds the fuse's rated value for a certain period of time, the fuse will melt or blow, interrupting the circuit and protecting the electrical system from damage. Therefore, the correct answer is current and time.
29.
When paralleling two circuits both employing voltage regulators the first action to take with the regulators is
Correct Answer
A. Disconnect the primaries
Explanation
When paralleling two circuits both employing voltage regulators, the first action to take with the regulators is to disconnect the primaries. This is because when the circuits are paralleled, the voltage regulators may have different output voltages. By disconnecting the primaries, it allows each regulator to independently regulate its own output voltage. Once the primaries are disconnected, the regulators can then be adjusted or set to ensure they are operating at the desired voltage level.
30.
The purpose of secondary breakers on an overhead system is
Correct Answer
A. Seperate secondaries of transformers
Explanation
Secondary breakers on an overhead system are used to separate the secondaries of transformers. This is important because transformers are typically connected in parallel, and each transformer has its own secondary winding. By using secondary breakers, the secondaries of different transformers can be isolated and controlled individually. This allows for better management of the electrical distribution system and ensures that power can be supplied to specific areas without affecting others.
31.
The purpose of a reclosing relay device is
Correct Answer
B. To prevent sustained outages due to transient faults
Explanation
A reclosing relay device is used to prevent sustained outages due to transient faults. Transient faults are temporary faults that occur in a power system, such as momentary short circuits or voltage spikes. By automatically detecting and isolating these faults, the reclosing relay device can quickly restore power to the circuit, preventing prolonged outages. Additionally, it helps protect the control circuit of the breaker by ensuring that it operates correctly during fault conditions. Therefore, the correct answer is "to prevent sustained outages due to transient faults."
32.
When making connections to a lightning arrestor being installed on a live system the
Correct Answer
C. High voltage connection must be made first
Explanation
When making connections to a lightning arrestor being installed on a live system, the high voltage connection must be made first. This is because the high voltage connection allows the lightning arrestor to safely divert the lightning strike or high voltage surge away from the system. By connecting the high voltage side first, it ensures that the lightning or surge is directed to the arrestor before reaching the system, protecting it from potential damage.
33.
When switching dead front systems with elbow connectors the
Correct Answer
A. Connector must be parked or grounded
Explanation
When switching dead front systems with elbow connectors, it is necessary for the connector to be parked or grounded. This ensures that the electrical current is safely diverted and prevents any potential hazards or accidents. By parking or grounding the connector, it is securely fixed and unable to move or cause any disruptions in the electrical system. This practice is important for the overall safety and functionality of the dead front system.
34.
A pole you are about to climb does not have a butt gain visible. you should
Correct Answer
D. Insure it is secure before climbing it
Explanation
The correct answer is to insure it is secure before climbing it. It is important to prioritize safety when engaging in any activity, especially climbing a pole. Since the pole does not have a visible butt gain, which could provide stability, it is necessary to ensure its security before proceeding. This can be done by checking for any signs of damage or weakness, using appropriate safety equipment, and following proper climbing procedures. Informing the supervisor and waiting for direction may also be necessary, but the immediate action should be to ensure the pole's security.
35.
Before connecting a voltage regulator to a live line it is necessary to
Correct Answer
A. Switch the regulator to neutral
Explanation
Before connecting a voltage regulator to a live line, it is necessary to switch the regulator to neutral. This is important because switching the regulator to neutral ensures that there is no voltage flow or electrical connection between the regulator and the live line. This step helps to prevent any potential electrical hazards or damage to the regulator or the electrical system.
36.
A precaution to take before opening a system neutral is to
Correct Answer
B. Eliminate all unbalanced loads before opening
Explanation
Before opening a system neutral, it is important to eliminate all unbalanced loads. This is because unbalanced loads can cause an imbalance in the electrical system, which can lead to potential hazards such as voltage fluctuations or overload. By eliminating unbalanced loads, the system can be stabilized and the risk of electrical issues can be minimized. Grounding the neutral conductor and setting the regulator on manual are not directly related to opening a system neutral, while providing an alternate path for the current is not mentioned in the question.
37.
You find an unconscious person your first action should be to check for
Correct Answer
B. Further danger
Explanation
When you come across an unconscious person, the first action you should take is to check for further danger. This involves assessing the surroundings to ensure that there are no immediate threats or hazards that could pose a risk to you or the unconscious person. By doing this, you can create a safe environment and prevent any potential harm before proceeding with any necessary medical assistance.
38.
A load break tool should be used when
Correct Answer
D. Opening cutouts under oad
Explanation
A load break tool should be used when opening cutouts under load. This is because cutouts are designed to protect electrical systems from overloads or faults, and opening them while there is still a load can cause arcing or electrical damage. The load break tool allows for a safe and controlled disconnection of the load before opening the cutout, preventing any potential hazards or damage to the electrical system.
39.
Snatch block used with wire rope are sized by the
Correct Answer
B. Diameter of their sheaves
Explanation
The correct answer is the diameter of their sheaves. Snatch blocks used with wire rope are sized based on the diameter of their sheaves. The sheave is the grooved wheel that the wire rope runs on, and its diameter determines the size of the block. A larger sheave diameter allows for a larger wire rope to be used, increasing the load capacity and reducing wear on the rope. Therefore, the diameter of the sheaves is an important factor in determining the appropriate size of snatch blocks for wire rope applications.
40.
If an employee is instructed to carry out a certain task, but does not fully understand the scope of the work, he shall
Correct Answer
A. Request further information
Explanation
When an employee is given instructions for a task but lacks a complete understanding of its scope, it is important for them to request further information. By seeking clarification, the employee can ensure that they have a clear understanding of what needs to be done and avoid any potential mistakes or misunderstandings. This demonstrates their proactive approach to work and their commitment to completing tasks accurately and efficiently.
41.
When lifting a heavy load with a boom equipped with a hydraulic winch, the inital lift should be down with
Correct Answer
A. The boom
Explanation
When lifting a heavy load with a boom equipped with a hydraulic winch, the initial lift should be done with the boom. This is because the boom provides the necessary strength and stability to lift the load safely. The winch, on the other hand, is responsible for controlling the speed and direction of the lift, but the initial lifting force should come from the boom itself.
42.
When a de energized line runs in close proximity and parallel to an energized high voltage line, a result which create a hazardous condition of the de energized line would be
Correct Answer
C. Induced voltage from the energized line
Explanation
When a de energized line runs in close proximity and parallel to an energized high voltage line, the hazardous condition of the de energized line is created by the induced voltage from the energized line. This occurs due to electromagnetic induction, where the changing magnetic field from the energized line induces a voltage in the de energized line. This induced voltage can be dangerous and pose a risk to personnel and equipment working on the de energized line.
43.
To stop bleeding from a cut artery one should apply
Correct Answer
A. Direct pressure to the wound
Explanation
To stop bleeding from a cut artery, applying direct pressure to the wound is the most effective method. By applying pressure directly to the wound, it helps to compress the blood vessels and reduce blood flow, allowing the blood to clot and the bleeding to stop. This method is commonly recommended as the first step in managing bleeding from a cut artery before seeking further medical assistance.
44.
Before entering a manhole the manhole should be checked for.
Correct Answer
D. Pressence of toxic gases
Explanation
Before entering a manhole, it is important to check for the presence of toxic gases. This is because manholes can contain hazardous gases such as methane, hydrogen sulfide, and carbon monoxide, which can be extremely dangerous and even fatal if inhaled in high concentrations. Checking for the presence of toxic gases ensures the safety of the person entering the manhole and helps prevent accidents or health risks.
45.
Two men are about to descend the same pole the second man should down
Correct Answer
A. When the first climber is away from the pole
46.
the term backfeed refers to a condition whereby
Correct Answer(s)
A. The primary fuse, due to a defect does not blow during a short circuit
B. Another source energizes the supply line after the line had been de energized by the supply
Explanation
Backfeed refers to a condition where another source energizes the supply line after it has been de-energized by the main supply. In this case, the primary fuse does not blow during a short circuit due to a defect. This means that even though there is a fault in the circuit, the primary fuse fails to protect the system by interrupting the current flow. As a result, another source is able to energize the supply line and potentially cause further damage or safety hazards.
47.
Rubber blankets should always be stored
Correct Answer
B. In a roll and never folded
Explanation
Rubber blankets should always be stored in a roll and never folded because folding can cause permanent creases and damage to the rubber material. Rolling the blankets helps to maintain their shape and integrity, preventing any potential issues that may arise from folding. Additionally, tying the rolled blankets ensures that they stay compact and organized, making them easier to store and retrieve when needed.
48.
When working on a de energized line saftey grounds must be placed
Correct Answer
B. As close as possibly on both sides of the work location
Explanation
When working on a de-energized line, safety grounds must be placed as close as possible on both sides of the work location. This is important because safety grounds provide a direct path for electrical current to flow in the event of an accidental energization, protecting workers from electric shock. By placing safety grounds as close as possible on both sides of the work location, the risk of current flowing through the work area and potentially causing harm to the workers is minimized.
49.
When opening a lightning arrestor ground be sure to
Correct Answer
A. Check the potential on the ground connection first
Explanation
Before opening a lightning arrestor ground, it is important to check the potential on the ground connection first. This is necessary to ensure that the ground is safe and does not pose any risk of electric shock. By checking the potential, one can determine if there is any residual voltage or electrical charge present in the ground connection. This step is crucial for the safety of the person opening the ground, as well as for the protection of the equipment and surrounding environment.
50.
Fused cutouts are generally are of an expulsion typse this principle is
Correct Answer
A. Expulsion of the arc due to the deionizing fibre line of tube
Explanation
Fused cutouts are generally of an expulsion type, which means that the arc is expelled or extinguished by the deionizing fiber line in the tube. The deionizing fiber line is designed to quickly remove the ionized particles and gases that form during the arc, effectively interrupting the flow of current and extinguishing the arc. This expulsion mechanism ensures the safe and efficient operation of the fused cutout by preventing the arc from causing further damage or hazards.