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Worksheetsaman4eke
Total questions: 253
Worksheet time: 2hrs 7mins
What are the two main parts of a 3-phase induction motor?
Stator and Commutator
Rotor and Commutator
Stator and Rotor
Commutator and Brushes
Stator and Windings
What is the main function of the stator in an induction motor?
To rotate the motor shaft
To provide the rotating magnetic field
To house the brushes and commutator
To store electrical energy
To support the rotor
How is the rotor of an induction motor connected to mechanical loads?
Through a direct electrical connection
Through a brush arrangement
Mounted on the shaft of the motor
Via a pulley system
Attached through gears
. What is the relation between the synchronous speed (Ns), frequency (f), and the number of poles (P) in an induction motor?
Ns = 60f/P
Ns = 120f/P
Ns = 240f/P
Ns = 360f/P
Ns = 180f/P
What type of rotor does a squirrel cage induction motor have?
Squirrel cage rotor
Wound type rotor
Commutator type rotor
Brushless rotor
Stepper rotor
Which law explains the induction of current in the rotor of an induction motor?
Ohm's Law
Faraday’s Law of Electromagnetic Induction
Kirchhoff’s Law
Coulomb’s Law
Newton’s Law
What is a key characteristic of a synchronous motor?
It operates at a speed lower than the synchronous speed
The rotor is synchronized with the stator’s rotating magnetic field
It requires brushes and a commutator
It can operate on both AC and DC supply
It operates at variable speed
Which type of motor is most commonly used in domestic appliances?
Three-phase induction motor
Single-phase induction motor
Synchronous motor
Stepper motor
DC motor
What is the main advantage of using a single-phase motor?
High efficiency
Low cost and simple construction
High power output
Versatility in speed control
Long lifespan
What principle does an induction motor operate on?
Direct current flow
Interaction of two magnetic fields
Magnetic flux linkage with rotor coils
Both b and c
Electrostatic principles
What kind of flux is produced in the stator winding of an induction motor when it is supplied with an AC current?
Constant magnetic flux
Alternating magnetic flux
Static magnetic flux
Residual magnetic flux
Pulsating magnetic flux
Which of the following is not a part of the construction of a stator?
Steel frame
Laminations of silicon steel
Shaft
Conductors
Insulating materials
. In a synchronous motor, what happens if a load greater than the breakdown load is applied?
The motor stops
The motor speeds up
The motor becomes desynchronized
The motor reverses direction
The motor overheats
What is the operating principle of currently know tracers?
Ultrasonic waves
Radio waves
Electromagnetic induction
optical fibers
capacitive coupling
How do tracers operate when there is no current flowing through the communication?
They amplify the existing current.
They use a battery to create a current.
They cannot operate without current
They use solar power to create current
They create a current thanks to a generator
. What is the advantage of using 2-3 operating frequencies of the generator for "active" cable routing?
It reduces the cost of the tracer
It makes the tracer more accurate.
It allows the tracer to locate cables that are buried deep underground.
It allows determining the location of the cable without direct connection to the communication
It makes the tracer easier to use
What is the difference between the "Success ATG" and "Athlete TEK A" devices?
The “Success ATG” receiver is different than the “Athlete TEK A
The "Athlete TEK A" is more accurate than the "Success ATG".
The "Success ATG" is easier to use than the "Athlete TEK A
The "Athlete TEK A" has a longer battery life than the "Success ATG".
The "Success ATG" is more expensive than the "Athlete TEK A".
What is the effect of moisture on the burning process?
It makes process faster.
It makes the process longer.
It has no effect on process
It makes process accurate.
It makes the process easier.
. What factors affect the EMF induced in the sensor?
The distance between the sensor and the cable.
The type of cable insulation
The presence of other cables in the vicinity.
Current distribution in the cable and the relative location of the sensor and cable.
The weather conditions
What is the range of audio frequency current that can be passed through the cable?
1 Hz to 10 Hz
10 kHz to 100 kHz
1 MHz to 10 MHz
1 GHz to 10 GHz
512 Hz to 33 kHz
What is the minimum transient resistance required for a stable spark discharge?
10 ohms
20 ohms
30 ohms
40 ohms
50 ohms
What factors affect the audibility of sound from the earth's surface?
The distance between the damage site and the listening point
Depth of the cable, soil density, type of damage, and power of the discharge pulse
The type of cable insulation.
The presence of other cables in the vicinity.
The weather conditions.
What is the principle of the thermal control method for detecting cable damage?
Detecting changes in the magnetic field around the cable
Detecting changes in the electrical current flowing through the cable.
Detecting changes in the sound waves emitted by the cable.
Detecting changes vibrations of cable.
Detecting heat radiation from heated bodies.
What is the purpose of using a 500-1000 Hz audio frequency generator in phase-to-phase damage search?
To detect phase-to-phase damage.
To generate a high voltage pulse to burn through the insulation.
To create a magnetic field that can be detected by a sensor.
To amplify the signal from the damaged cable.
To measure the resistance of the cable.
How does the signal intensity change when passing over a coupling and a damage point?
) It decreases over the coupling and increases at the damage point.
) Increases over the coupling, increases at the damage point, and disappears beyond the damage point
It increases over the coupling and decreases at the damage point
It remains the same over the coupling and the damage point.
It fluctuates randomly over the coupling and the damage point.
What is the principle of operation of a georadar?
Measuring the electrical resistance of the ground
Detecting changes in the magnetic field of the Earth
Using sound waves to create an image of the underground
Drilling holes in the ground and analyzing the soil samples.
The emission of ultra-wideband electromagnetic pulses into the probed medium and the registration of reflected signals from inhomogeneities and objects
What does a DC motor convert?
Mechanical energy into electrical energy
Direct current energy into mechanical energy
Alternating current energy into mechanical energy
Mechanical energy into direct current energy
Mechanical energy into alternating current energy
What rule is used to determine the direction of force on a conductor in a DC motor?
Fleming's Right-hand rule
Lenz's Law
Faraday's Law
Fleming's Left-hand rule
Ampere's Law
What role does the commutator play in a DC motor?
Converts mechanical energy into electrical energy
Reverses the current in each conductor as it passes from one pole to another
Generates the magnetic field in the motor
Supplies DC current to the motor
Provides a magnetic path to the main field flux
Which part of the DC motor supports the field poles and field winding?
Armature
Commutator
Yoke
Brushes
Shaft
What is the function of the armature core?
Produces a magnetic field when DC is passed through it
Houses the windings in the slot
Receives DC from the main supply
Converts DC into AC
Supports the bearings
How is the field winding connected in a shunt-wound DC motor?
In series with the armature
In parallel with the armature
Partly in series and partly in parallel with the armature
Connected to an external AC source
Not connected to the armature at all
What type of DC motor has no field winding and uses permanent magnets?
Separately excited DC motor
Shunt-wound DC motor
Permanent magnet DC motor
Series wound DC motor
Compound wound DC motor
Which type of DC motor has the armature current flowing separately from the field winding current?
Shunt-wound motor
Series wound motor
Compound wound motor
Separately excited DC motor
Permanent magnet DC motor
What is the main function of the brushes in a DC motor?
Produce a magnetic field
Receive DC from the main supply and supply it to the armature winding
Support the armature and field winding
Convert DC into AC
Distribute the main field flux uniformly
In a compound wound DC motor, how are the field windings connected?
Both in series with the armature
Both in parallel with the armature
One in series and one in parallel with the armature
Neither in series nor in parallel with the armature
Connected to an external AC source
Which part of the DC motor provides a low reactance path to the main field flux and armature flux?
Yoke
Brushes
Armature core
Commutator
Shaft
What does the shaft of a DC motor do?
Supports the bearings in which the armature rotates
Produces the magnetic field
Provides support to the armature, windings, and commutator
Collects DC from brushes and converts it into AC
Houses the windings in the slot
In what configuration are the armature and field winding exposed to the same supply voltage in a DC motor?
Series wound motor
Separately excited DC motor
Permanent magnet DC motor
Shunt-wound motor
Compound wound motor
What are the basic parts of a DC shunt motor?
Field windings, battery, and commutator
Field windings, armature, and a transformer.
Rotor, stator, and brushes.
Field windings (stator), a commutator, and an armature (rotor).
Commutator, stator, and a gearbox.
What happens when a DC shunt motor is turned ON?
The commutator reverses the current flow direction.
DC flows across the stator only
DC flows across the rotor only.
DC flows across the entire stator as well as the rotor, creating two fields particularly the pole as well as the armature
AC flows across the entire stator as well as the rotor
What is a characteristic of a shunt-wound motor?
It is incapable of running at a predetermined speed
It has a very expensive power supply
It is not suitable for industrial use.
It requires frequent maintenance
It is highly variable in speed without load adjustments.
Why is the power supply of a DC motor considered an advantage?
It is complex and hard to maintain
It requires constant adjustment
It is highly variable and unstable.
It is very expensive
It is unreliable in industrial settings
What is the primary function of a DC series motor?
The primary function of a DC series motor is to convert electrical energy into mechanical energy
DC series motors are primarily used to generate electricity from mechanical energy
The main purpose of a DC series motor is to produce magnetic fields
DC series motors are designed to convert mechanical energy into thermal energy
DC series motors are primarily utilized for data processing tasks.
What effect does the initial application of an external voltage source have on the torque and speed of a DC series motor?
The torque and speed decrease due to high resistance in the armature and winding
The torque and speed remain constant regardless of the applied voltage.
The torque and speed increase indefinitely as voltage is applied
The torque and speed increase initially due to the strong magnetic field generated by the large current flow through the winding.
The torque and speed decrease initially due to low current in the winding
What is a notable advantage of DC series wound motors?
Excellent speed control and regulation
Limited application due to single power supply compatibility.
Low starting torque compared to other motor types
Restricted power output for a given construction size.
High starting torque, making them suitable for traction applications
Which type of motor combines both series and shunt field coils, ensuring ample magnetic flux to interact with the armature coil and supply the requisite torque for rotation?
Universal motor
Synchronous motor
Induction motor
Compound wound DC motor
Brushless DC motor
What are advantages of a DC Compound Wound Motor?
Quick starting and stopping capability
Low operational noise
High efficiency at low speeds
Limited maintenance requirements
Variable speed control
What is a disadvantage of a DC Compound Wound Motor?
Low initial cost
Spark-free operation
Compatibility with hazardous environments
Inherent safety features
Expensive operation and maintenance costs
Which application typically requires a Series Motor due to its need for high starting torque and variable speed?
Vacuum cleaners
) Lathes
Printing presses
Electrical fraction work
Boring machines
What is the function of the commutator in a DC shunt motor?
To regulate the voltage supplied to the armature
To reverse the direction of current flow in the armature windings
To control the speed of the motor
To transfer power from the stator to the rotor
To stabilize the magnetic fields in the motor
How does a DC shunt motor maintain continuous rotation of the armature?
By adjusting the voltage supplied to the stator windings
Through frictional contact between the brushes and commutator segments
By inducing magnetic fields within the armature windings
Via the interaction of magnetic fields between the armature and stator
By varying the speed of the rotor
What is the most common cause of damage to 1-10 kV voltage cable lines?
Pre-existing mechanical damage
Direct mechanical damage by construction and other organizations
Defects in connector joints and end seals during installation
Cable and joint damage due to ground settling
Corrosion of metallic cable sheaths
Which method involves connecting the cable to a high-frequency voltage source and listening to the cable route using an antenna frame with headphones to detect damage locations?
Inductive Method
Acoustic Method
Impulse Method
Burn-Through Method
both c and d
Which method involves creating periodic electrical discharges at the site of damage, accompanied by sound effects like clicks for defect localization?
Inductive Method
Acoustic Method
Impulse Method
Burn-Through Method
Thermal Imaging Method
Which method involves sending an electric signal into the cable and measuring the time of its reflection return to determine the distance from the end of the cable to the site of damage?
Inductive Method
Acoustic Method
Impulse Method
Burn-Through Method
Resistance Method
Which method involves burning the damaged insulation gap by passing current through the formed transitional resistance, generating a large amount of heat at the site of damage?
Inductive Method
Acoustic Method
Impulse Method
Burn-Through Method
Thermal Imaging Method
Which procedure involves the installation of connector joints at cable breakthrough points to restore the cable line?
Restoration of Damaged Armor
Repair of Cracks, Tears, or Punctures in the Outer Sheath
Installation of Connector Joints at Cable Breakthrough Points
Replacement of Damaged Connector and End Joints
None of the above
What is the recommended method for sealing minor holes in the protective hose covers of a cable?
Welding
Soldering
Applying PVC filler rod
Using duct tape
None of the above
In the event of significant damage with short-circuited cores, what is the appropriate repair method for restoring the cable line?
Soldering the damaged cores
Installing a connector joint
Applying additional steel tape
Using heat shrinkable elements
None of the above
What combination of methods is commonly employed to locate the point of damage in an underground cable route?
Acoustic and visual methods
Inductive and burn-through methods
Acoustic and inductive methods
Visual and burn-through methods
None of the above
What is the purpose of employing a combination of detection methods for locating damage in underground cable routes?
To increase the complexity of the repair process
To reduce the precision of damage localization
To avoid excavation work altogether
To narrow down the search area
None of the above
What are the main types of protective structures used during the installation of cable lines?
Wooden crates and barrels
Metallic and plastic corrugated sleeves
Glass containers and boxes
Cardboard tubes and cylinders
None of the above
What is the purpose of laying cable lines on a sand cushion during underground installations?
To provide a comfortable resting place for the cables
To prevent cable damage due to soil displacement
To create a decorative pattern on the ground surface
To increase the weight of the cables
None of the above
Where are metallic or plastic corrugated sleeves commonly used during cable installations?
Underwater locations
Indoor installations
Mountainous regions
Desert areas
None of the above
What is cable Tracing?
the most resistant to aggressive environments
is such an engineering and survey operation, during which the exact coordinates are determined.
sold for electrical projects carries labeling to help you choose right product for your needs
space for cables is limited and crunched, especially the urban regions
1.5m deep and 0.45m wide trench which is then covered with a layer of sand
What is Signal generator?
are devices that are primarily designed for testing transmitters, specialists use them to measure the characteristics of analog converters
) the principle of the bolted connector of cores for two cables
is designed to assemble cores wrapped with a special grade of paper
ducts or conduits of cast iron or concrete or glazedstone
a range of approvals need to be obtained from relevant authorities
Induction sensor is..?
The technique works for conductive cores that are energized in the ground
A similar principle of operation
A simple and affordable method based on the principle of the formation of electrical oscillations of different frequencies
The simplest and cheapest method of underground cable laying
The cable route needs to be designed keeping in mind
How works a signal guidance?
Connecting, for connecting cable segments to each other.
The cut wire is connected to the end terminal.
Used as locking elements for insulation of paper-impregnated cables
With the help of a special compact radio locator, a signal is sent that determines the presence of a cable underground by electrical impulses passing inside it.
Adheres to the cable elements and hermetically protects them
What you need to trace and identify the ends of cables, conductors and cable channels?
Underground cable
Multimeter.
Tone generator and Inductive Probe
Voltmeter and signal generator
Clamp meter.
Test 701Kit is used for..?
to search for wires on a line or in bundles, identify breaks and short circuits.
installing poles whereas it require a limited band of land
cable laying, quality of cable joints and branch connections
pulling the cable in position.
filling the troughs once thecable is laid in position
Working principle of Tine generator and Inductive probe?
is carried out outdoors inside trenches or repair pits
is to search for a traceable cable or channel by the signal induced in it
is to remove moisture from the coupling
to use tips made with a hole for monitoring.
is forbidden to cross the phases when paraphrasing.
The sensor can detect fields generated by other signal sources:
power lines; telephone cables; radio transmission networks; conducting lines at 140-300 kHz;
direct laying; draw in system; solid system;
maintenance cost; approvals; modifications; requirements
voltage value; number of veins;
multimeter; clamp meter; voltmeter; ammeter
What allows you a cable tracing?
to be obtained from relevant authorities
to protect against mechanical injury
to perform them in a single sealed enclosure.
to connect cables with a shell made of aluminum
to determine the direction and location of hidden extended objects, mainly cables
Cable locator has same operation as..
Test 701Kit.
Signal guidance.
Cable detector.
Power lines
Multimeter.
Same parameters of sensor and generator.
underground utilities, cables in buildings, power lines, metal channels.
Accident prevention, Continuous, Zero obstruction
quality of cable joints and branch connections.
asphalt, stoneware and cast iron.
nothing
What components are included in the TEMPO CTS 132j cable tracing kit?
Transmitter and receiver
Transmitter and coil
Coil and probe
Transmitter, coil, and probe
Receiver and probe
Which of the following shielding types can effectively block the electric field produced by the cable tracing kit?
Inner shell
Outer foil shell
Inner shielding
insulation
Grounding
Why is underground cable laying preferred in urban regions with limited space?
Underground cables are cheaper to install.
Overhead cables obstruct the view in urban areas.
Underground cables require less maintenance
Overhead cables are more susceptible to damage from weather conditions.
Underground cables ensure uninterrupted service in cramped spaces.
What advantage do underground cables offer over overhead cables in terms of aesthetics?
Underground cables are cheaper to install.
Overhead cables obstruct the view in urban areas.
Underground cables require less maintenance
Overhead cables are more susceptible to damage from weather conditions.
Underground cables are not visible to the naked eye, preserving the location's aesthetic beauty.
What is an essential requirement to ensure the success of underground cable laying in urban areas?
Using cheaper cable materials
Avoiding systematic planning
Digging proper trenches
Prioritizing overhead cable installation
Installing cables without proper inspection
What advantage does underground cable systems offer in terms of accident prevention?
Aerial cables are cheaper to install
Underground cables require more maintenance
Aerial cables are less prone to damage from falling tree branches
Underground cables can collapse on buildings and cars.
Underground cable laying is safer due to reduced risk of electric shocks
How do underground cable systems ensure continuous service compared to aerial cables?
Aerial cables require more space for installation.
) Underground cables are more visible to the naked eye
Aerial cables have a longer lifespan
Underground cables are prone to frequent maintenance
Underground cables are protected from external factors, ensuring uninterrupted power or service.
What benefit does underground cable laying offer in terms of space requirement?
Underground cables require more space for installation
Aerial cables obstruct the view in urban areas
Underground cables are less durable than aerial cables
Aerial cables provide better protection from harsh weather conditions
Underground cables require a much-limited band of land compared to aerial cables
What is an advantage of the direct laying method for underground cable laying?
It requires less space for trenching
The cables are laid above ground for easy access
It is the most expensive method of cable laying.
It is the simplest and cheapest method of underground cable laying
The heat generated is trapped within the cables
What is a disadvantage of the direct laying method for underground cable laying?
It has a high maintenance cost.
Pointing out accurate locations of faults is easy.
Cable network alterations are straightforward.
The heat generated dissipates into the surrounding ground
It requires minimal maintenance
What is a challenge associated with underground cable laying?
Low installation cost
High installation cost due to restoration expenses
Flexibility in making modifications to the line
Lack of obstacles in the cable route
Easy obtainment of permissions and approvals
What requirement adds to the complexity of laying underground cables?
Low voltage flow
Minimal need for insulation
Easy modifications to the line
Layers of insulation needed to withstand high voltage flow Lack of permissions and approvals
Lack of permissions and approvals
What is a disadvantage of the solid system for underground cable laying?
Low installation cost due to minimal skill requirements
Weak mechanical protection
Use of asphalt, stoneware, or cast iron for troughs
Low cost of labor
High skill and labor requirements leading to high costs
What is an advantage of the draw in system for underground cable laying?
It has a low installation cost
Manholes make additions, repairs, and maintenance easy
Repairs and maintenance are difficult
Mechanical protection increases maintenance costs
Manholes increase the occurrence of faults.
What is a disadvantage of the draw in system for underground cable laying?
It has low maintenance costs
Mechanical protection increases the occurrence of faults
The installation cost is high
Heat dispersion is high due to grouped cables
Manholes are not used in the draw in system.
Which cooling method is generally used for small dry type transformers up to 3 MVA?
Air Blast
Oil Natural Air Natural (ONAN)
Oil Forced Air Forced (OFAF)
Air Natural
Oil Forced Water Forced (OFWF
For dry type transformers rated more than 3 MVA, which cooling method is recommended?
Oil Natural Air Forced (ONAF
Oil Forced Air Forced (OFAF)
Air Natural
Oil Forced Water Forced (OFWF)
Air Blast
In the Oil Natural Air Natural (ONAN) cooling method, how is heat dissipated from the oil to the atmosphere?
By natural air flow surrounding the transformer and natural convection within the oil
By using fans to force air over the oil
By circulating water through heat exchangers
By forced air flow through heat exchangers
By directing oil flow through predetermined paths
What component is often used in the Oil Natural Air Forced (ONAF) cooling method to enhance heat dissipation?
Separate coolers for heated water
Pumps for forced oil circulation
Fans mounted near the radiator, often with an automatic starting arrangement
Air filters to prevent dust accumulation
Pre-decided oil flowing paths between insulated conductors
Which cooling method involves forced circulation of oil through heat exchangers, with compressed air forced to flow on the heat exchanger using fans?
Oil Forced Air Forced (OFAF
Oil Forced Water Forced (OFWF)
Air Natural
Oil Natural Air Natural (ONAN)
Air Blast
In which cooling method is forced water flow used to dissipate heat from the oil via heat exchangers?
Oil Natural Air Natural (ONAN)
Oil Forced Air Forced (OFAF)
Oil Natural Air Forced (ONAF)
Oil Forced Water Forced (OFWF)
Air Natural
What is the maximum transformer rating typically cooled by the Oil Natural Air Forced (ONAF) method?
3 MVA
15 MVA
30 MVA
Several hundreds MVA
60 MVA
Which cooling method for oil immersed transformers relies on natural convection and air flow to dissipate heat?
Oil Forced Water Forced (OFWF)
Air Natural
Oil Forced Air Forced (OFAF)
Oil Natural Air Natural (ONAN)
Air Blast
What is the primary method of heat dissipation in the Air Blast cooling method for dry type transformers?
Natural air flow surrounding the transformer
Forced air on the core and windings with the help of fans or blowers
Natural convection within the oil
Circulating water through heat exchangers
Forced air on the heat exchanger using fans
For which type of transformers is the Oil Forced Water Forced (OFWF) cooling method primarily used?
Small transformers up to 3 MVA
Medium transformers up to 15 MVA
Large transformers up to 60 MVA
Very large transformers with ratings of several hundreds MVA
Dry type transformers rated more than 3 MVA
How does the Oil Directed Air Forced (ODAF) cooling method improve the heat dissipation process?
By using natural convection within the oil
By directing oil to flow through predetermined paths in the transformer winding for faster heat transfer
By forced water circulation in heat exchangers
By applying forced air over the entire transformer surface
By using fans and blowers to direct air flow through ventilation ducts
What is the main difference between the ODAF and ODWF cooling methods for transformers?
ODAF uses natural convection, while ODWF uses forced water.
ODAF uses forced water, while ODWF uses natural air.
ODAF uses forced air to cool the oil, while ODWF uses forced water
ODAF uses natural air, while ODWF uses natural water
ODAF uses air blasts, while ODWF uses water coolers.
In the Air Natural or Self Air Cooled Transformer method, how is cooling achieved?
By circulating water through the heat exchangers
By natural air flow surrounding the transformer
By forced air flow over the heat exchangers
By using fans to blow air through ventilation ducts
By directing oil flow through predetermined paths in the transformer winding
What is the main advantage of using Scotchlok connectors in electrical installations?
They prevent oxidation of electrical contacts
They require stripping of the insulation
They increase transition resistance
They lead to loss of electrical contact
They result in circuit failure
Which electrical connectors are known for their ability to prevent oxidation of electrical contacts and ensure a high level of protection from environmental influences?
) Soldering connectors
Scotchlok connectors
Twist-on wire connectors
Crimp connectors
Wire nuts
What feature of Scotchlok connectors eliminates the need to strip insulation during installation?
Metallic contact
Hydrophobic filler
Piercing mechanism
Cover and connector housing
Pliers with parallel jaws
In what type of conditions are Scotchlok connectors with hydrophobic filler ideal for use?
Indoor environments only
) Low humidity conditions
Underground installations
In airtight enclosures
Areas with high levels of condensation
What is the purpose of the thermoplastic adhesive layer inside repair sleeves for power cables?
To provide electrical conductivity
To prevent shrinkage during installation
To create a visual indicator of overheating
To fill voids and gaps during shrinkage
To enhance flexibility during cable splicing
What role does the stainless steel band play in the design of repair sleeves for power cables?
Providing electrical insulation
Facilitating shrinkage of the sleeve
Preventing corrosion and destruction
Indicating the completion of shrinkage
Enhancing the flexibility of the sleeve
What is the primary purpose of using encapsulating splice technology for connecting and repairing control cables?
To increase electrical conductivity
To enhance flexibility of the cables
To simplify and speed up the installation process
To eliminate the need for Scotchlok connectors
To reduce the size of the cables
What is the final step in installing a splice using encapsulating splice technology?
Connecting the cables with soldering
Applying heat shrink tubing
Installing an encapsulating mold
) Using a hydraulic press
Pouring a polyurethane mixture through a receiving valve
What is the purpose of Closed Mixing and Pouring (CMP) technology during the installation of encapsulating splices?
To increase the flexibility of the compound
To facilitate the contact of the compound with hands
To prevent an exothermic reaction
To ensure solidification of the mixture
To decrease the mechanical strength of the compound
Why is additional insulation between Scotchlok connectors not required when using encapsulating splice technology?
Because it increases the risk of electrical shock
Because the compound provides reliable electrical insulation
Because it accelerates the exothermic reaction
Because it reduces the mechanical strength of the splice
Because it prevents solidification of the compound
What is included in the 3M 3101 tape kit for repairing control cables?
Soldering iron and flux
Wire strippers and cutters
Electrical insulation mastic
PVC pipes and fittings
Paintbrushes and rollers
How many self-amalgamating electrical insulation tapes are included in the 3M 3101 tape kit?
None
One
Two
Three
Four
How long does it typically take for the encapsulating compound to harden after the completion of installation?
30 minutes
1-2 hours
4-6 hours
12-24 hours
48 hours
What serves as additional protection for the spliced area from external factors after encapsulation?
PVC tape
Rubber mastic tape
Self-amalgamating tape
Encapsulating mold
Electrical insulation mastic
What is the recommended action to reduce heat loss after installing a heating cable on a pipeline?
Place the pipeline below the frost line
Install the heating cable at temperatures below -15°C
Insulate the pipes after installation, as this significantly reduces heat loss
Do not use any insulation for the pipes
Use a double layer of heating cable for maximum efficiency.
Which of the following statements about installing heating cables is accurate?
) It is mandatory to install the cable without protective covering on synthetic pipes for safety purposes
Install the cable at temperatures below -15°C to ensure it functions properly.
Marks indicating the installation of heating cables must be made on the pipes and in the trench with the pipe. A warning signplate is mandatory
The bending diameter of the cable should be less than six times the diameter of the cable itself
Heating cables can be installed through shut-off valves for ease of access
What precaution should be taken regarding the installation of heating cable inside the pipe to ensure safety and efficiency?
Using any available fittings for routing the cable
Installing the cable through shut-off valves
Ensuring all bends with in the pipe are natural curves
Ignoring the need for warning labels.
Securing the cable adhesive tape at regular intervals
What is prohibited when fixing the power cable and connection joint during the installation of heating cable inside the pipe?
Using factory tape to cover threads on fittings
Routing the cable through shut-off valves.
Carefully avoiding damaging the cable insulation
Using passage and gland from the cable entry kit into the pipe
Installing the cable without protective sheathing
What factors are important to consider when selecting and calculating heating cable for pipe heating?
Only the purpose of the pipe and its diameter.
The specific section of the pipe and the material it has made of
The type of insulation used and the brand of the heating cable
The color of the pipe and its location.
The type of liquid transported in the pipe
How is the heat loss per meter of pipe length calculated in the process of selecting heating cable?
By guessing the heat loss based on the pipe's diameter
By measuring the temperature of the surrounding environment
By using advanced thermal imaging technology
By considering factors such as pipe material, diameter, and insulation
By testing different cables and observing performance.
) What is the purpose of determining the required length of the heating cable kit in the selection process?
To estimate the color scheme of the heating cable
To ensure compatibility with shut-off valves
To calculate the number of fittings needed for installation.
To ensure sufficient coverage for the specific section of the pipe with appropriate heat output.
To match the cable length with the pipe diameter.
What is a key difference between resistive and self-regulating heating cables for pipe heating?
Resistive cables are used for external heating only
Self-regulating cables require manual adjustments
Resistive cables are designed for large diameter pipes
Self-regulating cables adjust their power output based on the temperature.
Resistive cables are cheaper but less efficient
Why are heating cables inside pipes with drinking water used?
To provide a backup heating system
Because they are cheaper than external cables
When it is not possible to heat the pipe externally, such as when the pipe is already buried.
To reduce the need for pipe insulation materials
To increase the overall efficiency of the heating system
What is the maximum diameter for water pipes that can use internal heating cables, and what is the power range for these cables?
Up to 50 mm and 5-10 W/m
Up to 25 mm and 10-15 W/m
Up to 32 mm and 9-13 W/m.
Up to 40 mm and 8-12 W/m.
Up to 45 mm and 11-14 W/m.
What is a critical consideration when using heating cables for frost protection on polyethylene and plastic pipes?
Ensuring the cable is colorful
Choosing a cable that is at least 30 W/m.
Using a cable that is 17 W/m or less to prevent damage
Selecting a resistive cable for higher efficiency
Matching the cable length to the pipe diameter
What is the recommended type of heating cable for fan pipes that operate at a non-intensive rate?
A 23 W/m resistive cable
A 30 W/m self-regulating cable.
Any cable that is over 20 W/m for efficiency
A 17 W/m cable like the 17KSTM, suitable for both external and internal use
A 15 W/m resistive cable for maximum performance
Why must the power of the heating cable be carefully calculated when used externally on water pipes?
) To ensure the cable lasts longer
To match the aesthetic of the building
To avoid exceeding the maximum allowable temperature for the pipe material, preventing damage
To guarantee the cable is easily replaceable.
To ensure the cable is compatible with other heating systems.
Induction system devices are widely used for measuring?
electrical system
measuring mechanism
electrical energy
power measurement
voltage measurement
Which of the following is not a criterion for classifying electrical measuring devices?
Measurement method
Type of measured value
Type of current
Brand of the device
Degrees of accuracy
The operation of ferro dynamic devices is the same as the devices of the?
Electrostatic Voltmeter
Magnetoelectric switch ammeters
Induction system
Electrodynamic system
Single-phase induction counter
Which of the following principles of operation does the induction system rely on?
Interaction of magnetic fluxes created by current and voltage coils with eddy currents
Direct measurement of electrical resistance
Conversion of electrical energy into light
Generation of static magnetic fields
Measurement of capacitance through charge storage
Measurement of phase shift angle?
) frequency meters
electric meters
ammeters
phase meters
wattmeters
How are devices categorized according to their degree of accuracy?
0.1-5
0.5-3
1-10
1.5-4.5
0.05 -4
The advantage of the devices of the magnetoelectric system is the?
High-speed re-closures facility
Need less maintenance
Uniformity of the scale
High-speed operation
Risk of fire can be reduced
What is the primary source of measurement errors in devices with rectification circuits?
The dependence of the volt-ampere characteristics of rectifier diodes on temperature
The quality of the insulation material used in the device
The length of the connecting wires in the circuit
The type of display used in the measurement device
The ambient humidity levels around the device.
Which of the following electrical measuring devices is used for power measurement?
Voltmeter
Ammeter
Galvanometer
Wattmeter
Millivoltmeter
In devices of direct evaluation, what represents the measure?
The divisions of the scale of the counting device
The voltage drop across the device
The frequency of the input signal
The color of the display
The size of the device casing.
Which of the following factors is not part of the formula used to determine the relative error of a device for accuracy class?
Readings of the device being verified
Readings of an exemplary device (A0)
Maximum value of the measured value (Amax)
Environmental temperature (T)
Measurement limit (Amax)
Which type of device is used as panel ammeters, wattmeters and voltmeters?
Ferro dynamic devices
Magnetoelectric devices
Thermocouple devices
Electromagnetic devices
Photoelectric devices
Which of the following systems does an electrical measuring device based on the interaction of magnetic fields and electric currents belong to?
Electrodynamic
permanent magnetic
Magnetoelectric
Thermoelectric
Photoelectric
What law is the principle of measuring operating voltage based on?
Newton's law
Coulomb's law
Ohm's law
Thermodynamics law
Faraday's law
What value is used to describe harmonic signals?
Oscillation period (T)
Acceleration (a)
Energy (E)
Oscillation frequency (f)
Impulse (J)
What device allows you to measure the potential difference?
Electrostatic ohmmeter
Electrostatic ammeter
Wattmeters
Bolometer
Electrostatic voltmeter
How many types of measuring transformers are divided into?
2
6
1
3
5
What types of measuring transformers are there?
Voltage and current transformers
Frequency transformers
Resistance transformers
Universal transformers
Isolation transformers
Measuring transformers are manufactured with a power range of
Five to thousand volt-amperes
) Fifty to hundred volt-amperes
Five to several hundred volt-amperes
Ten to several hundred volt-amperes
Hundred volt-amperes
What types of errors are distinguished in voltage measuring transformers?
Only relative voltage inaccuracy
Relative voltage inaccuracy and angular inaccuracy
Observational error
Instrumental error
Only angular inaccuracy
Which of the following statements is true about the voltage transformers manufactured by the industry?
They retain the accuracy class when the primary voltage exceeds 120% of the nominal
They lose the accuracy class when primary voltage changes from 80 to 120% of the nominal
They retain the accuracy class when the primary voltage changes from 80 to 120% of the nominal
They retain the accuracy class only when primary voltage is exactly at the nominal value
They retain the accuracy class only when the primary voltage is below 80% of the nominal
How many accuracy classes are stationary voltage transformers divided into?
7
4
5
3
2
Choose the right accuracy classes for laboratory voltage transformers:
0.05; 0.1; 0.2 and 0.5
0.5; 1 and 3
0.2; 0.5 and 1
0.01; 0.02; 0.05
0.1 and 0.2
What is the principle of operation of the current measuring tongs?
The device utilizes the principle of electromagnetic radiation
The device measures direct current flow through a wire
The device's core is permanently fixed to the wire
The device functions as a voltage transformer
The principle of operation is based on the phenomenon of electromagnetic induction
What determines the movement of the moving electrode in the Electrostatic voltmeter?
The accumulation of charges on both electrodes
The application of an external magnetic field
The interaction between charges described by Coulomb's law
The temperature gradient across the electrodes
The rate of electron transfer between the electrodes
How many accuracy classes are stationary current transformers divided into?
4
5
3
6
2
What is the configuration of the windings in an electrodynamic wattmeter for measuring power P ?
Current winding in parallel and voltage winding in series
Voltage winding in series and current winding in parallel
Both windings in series
Current winding in series and voltage winding in parallel
Both windings in parallel
What is the principle of operation of induction devices?
Interaction of direct magnetic fluxes with stationary conductors
Interaction of alternating magnetic fluxes with currents induced in a movable conductor
Interaction of direct magnetic fluxes with currents induced in a stationary conductor
Interaction of alternating magnetic fluxes with stationary conductors
Interaction of alternating currents with a fixed conductor
What are the main elements of a classic induction meter?
One magnetic core with a current winding, a rotating disk, and a counting mechanism
One magnetic core with a voltage winding, a stationary disk, and a counting mechanism
Two magnetic cores with their own windings, a rotating disk, and a counting mechanism
Two magnetic cores with a shared winding, a rotating disk, and a counting mechanism
Two magnetic cores with stationary windings, a stationary disk, and a counting mechanism
In the operation of the counter, what happens to the main magnetic flux generated by the current in the voltage winding?
It closes inside the magnetic core
It crosses the rotating disk
It dissipates into the air
It creates a secondary current
It remains stationary
What is used in circuits with voltages and/or currents greater than the nominal ones for a particular meter?
Voltage stabilizers
Current regulators
Voltage and/or current measuring transformers
Induction coils
Capacitors
What do induction meters measure besides active energy?
Voltage drop
Resistance
Reactive energy
Apparent power
Frequency
Why is it necessary to measure resistances in electrical machines and installations?
To monitor voltage levels
To ensure normal operation
To control current flow
To maintain frequency
To adjust power output
What range of electrical resistance is considered medium?
Less than 1 ohm
1 ohm to 0.1 megaohm
0.1 megaohm and above
Less than 0.1 ohm
1 megaohm and above
What components are included in the group of small resistances?
Transformer windings
Busbar short wires
Inductor coils
Circuit breakers
Capacitors
What precaution should be taken before starting resistance measurements?
Clean the insulation from dust and dirt
Rotate the generator handle quickly
Ensure there is voltage on the tested object
Use wires with low insulation resistance
Discharge the test object after measurements
What is the purpose of the control check before using a megohmmeter?
To verify the voltage level
To ensure proper grounding
To check the insulation resistance of the wires
To calibrate the instrument
To verify the accuracy of the instrument
What factors can influence the magnitude of resistance when testing?
Type of current
Magnitude of voltage
Duration of voltage
Temperature
All of the above
When measuring the resistances of insulating materials, what must be considered regarding the current passing through them?
Only through the volume
Only on the surface
Both through the volume and on the surface
Depends on the material type
None of the above
What is Conrol Cables?
the lifeline of automated systems, instrumentation, and applications of similar nature.
Its a metal in the form of a usually very flexible thread or slender rod.
An apparatus for reducing or increasing the voltage of an alternating current
a device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator.
For what they are used for?
used in electronic circuits for blocking direct current while allowing alternating current to pass
to connect instrument transformers, coils of circuit breakers and contactors, control switches, meters, protection devices and other control and monitoring equipment
used to change AC voltage levels
used to bear mechanical loads
used in electrical and electronic systems, a conductor or group of conductors for transmitting electric power or telecommunication signals from one place to another
Which of the following features is essential for ensuring the faultless functioning of control cables in automated systems?
The control cables must be protected with a foil shield, braid shield, or a combination of both.
Control cables should be made with a single core for simplicity
The control cables need to be flexible to suit different construction and installation scenarios
Control cables should only be used in stationary applications to avoid wear and tear
Control cables must be shielded with only foil for the best performance.
Which feature is most crucial for identifying individual cores in control cables used in automated systems?
Each core should be identified by a different color or by a number marked on the insulation.
All cores should be the same color to simplify manufacturing
Control cables should only have one core to avoid confusion.
The cores should be marked with letters instead of numbers for better identification.
The cores should not have any identification marks to reduce costs.
Which characteristic is essential for protecting control cables from electromagnetic interference in automated systems?
The control cables should have proper shielding, such as a foil shield, braid shield, or a combination of both.
The control cables should be made entirely of plastic to reduce cost
The control cables should have no shielding to maintain flexibility
The control cables should be used only in non-electromagnetic environments to avoid interference
The control cables should have a metallic core to block electromagnetic waves.
Which of the following is an application of control cables in the automation and instrumentation sectors?
Control cables are used to power small household appliances
Control cables are mainly used for decorative purposes in electrical systems
Control cables are used exclusively in residential lighting systems
Control cables are used exclusively in residential lighting systems
Control cables are ideal for use in the power distribution sector due to their flexibility and performance.
In which of the following areas are control cables typically used, according to their design and specifications?
Decorative home lighting
Household plumbing systems
Gardening equipment
Production centers and assembly lines
Furniture manufacturing
Which area of application is ideal for using braid shielded, foil shielded, flat, and woven control cables?
Production centers and automated systems
Residential kitchen appliances
Outdoor landscaping
Office furniture
Personal electronics
What are some common technical specifications of control cables that determine their suitability for different applications?
) Gauge sizes from 1 AWG to 5 AWG, voltage specifications of 700 V to 1000 V, and temperature limits up to 50°C
Gauge sizes from 10 AWG to 50 AWG, voltage specifications of 100 V to 200 V, and temperature limits up to 100°C
Gauge sizes from 28 AWG to 2 AWG, voltage specifications of 300 V to 600 V, and temperature limits up to 900°C
Gauge sizes from 2 AWG to 10 AWG, voltage specifications of 200 V to 500 V, and temperature limits up to 200°C
Gauge sizes from 20 AWG to 30 AWG, voltage specifications of 50 V to 150 V, and temperature limits up to 300°C
Which of the following is an advantage of using control cables in various applications?
Flexibility to suit any structure
High susceptibility to interference
Limited application to a single sector
Short service life
Corrosive material
Why do three-phase induction motors not require additional starting devices?
They operate on direct current
They have built-in starting devices
They are self-starting
They use mechanical energy to start
They have a special rotor design
What happens to the rotor in a three-phase motor when a three-phase supply charges the motor?
It stops rotating
It starts rotating in the same direction as the stator's magnetic field
It creates a stationary magnetic field
It generates a constant magnetic field
It reverses its direction
What generates current in the rotor conductors of a three-phase motor?
The constant magnetic field from the rotor
The variable magnetic field cutting the rotor conductors
The stationary magnetic field of the stator
The direct current supply to the motor
The resistance of the rotor conductors
Why are the slots on a squirrel cage rotor slightly skewed?
To increase the weight of the rotor
To enhance the magnetic field strength
To reduce noise from magnetic hum and ensure smooth operation
To make room for additional conductors
To increase the electrical resistance in the rotor
What produces torque in a squirrel cage induction motor?
The interaction of magnetic fields generated by the stator and rotor windings
The rotation of the stator alone
The presence of an external resistor
The static magnetic field of the rotor
The adjustment of the rotor bar size
What causes the rotor to start rotating in a squirrel cage induction motor?
The presence of an external resistor
The direct current supply to the rotor
The short-circuit currents in the rotor bars produce a magnetic field that interacts with the stator's rotating magnetic field
The mechanical connection to the stator
The adjustment of rotor bar size
) What happens to the rotor current when the rotor catches up to the rotating magnetic field in a squirrel cage induction motor?
The rotor current increases
The rotor current remains constant
The rotor current drops to zero
The rotor current reverses direction
The rotor current doubles
What type of connection does the phase wound rotor in the induction motor have?
Delta connection
Star connection
Mesh connection
Parallel connection
Series connection
What is the primary advantage of using a slip ring induction motor over a squirrel-cage induction motor?
Higher efficiency
Lower maintenance
Greater starting torque
Smaller footprint
Quieter operation
What is the primary advantage of AC motors in terms of maintenance?
Higher efficiency
Variable speed control
Lower maintenance cost
Greater starting torque
Reliable operation
What is a disadvantage of AC motors?
High current generation due to back EMF
Inability to operate at low speeds
Good positioning control
Limited torque capabilities
Higher maintenance requirements
What type of motor is commonly used for industrial drives of water pumps, tube wells, lathes, and drills?
Double cage motor
Phase wound motor
Synchronous motor
Single-phase motor
Squirrel cage motor
Where we use couplings?
homes
schools
high-voltage cable lines.
factories
offices
For what we need lead couplings?
They are also used as locking elements for insulation of paper-impregnated cables
designed to connect cables with a shell made of aluminum or lead
They are used to prevent the runoff of the impregnating mass
For protection
a) For installation
How many is diameter of pipes of lead couplings?
6-11 cm.
3-5 cm
2-4 cm
8-15 m
10-12 cm
How many is length of pipes of lead couplings?
20-30 cm
10-20 cm
45-65 cm
70-80 cm
40-50 cm
What is a critical design feature for power cable lines?
Using multiple separate enclosures for each cable
Ensuring the cables are exposed to the environment for better cooling
Performing them in a single sealed enclosure
Coating the cables with an unsealed protective layer
Burying the cables without any additional protective measures
When connecting power cable segments, how is the insulation from each core removed?
The insulation is removed for the entire length of the connecting tube
The insulation is removed by half the length of the connecting tube
The insulation is not removed
The insulation is removed by one-quarter the length of the connecting tube
The insulation is removed entirely
What is the primary purpose of wrapping epoxy couplings
To enhance electrical conductivity
To provide additional insulation for high-voltage cables
To protect the couplings from possible mechanical damage
To improve the flexibility of the cables
To increase the length of the cables
What materials are used to create stopper of locking couplings?
Gold rods
a) Silver rods
) Aluminum rods
Copper and aluminum rods.
Copper rods
It is impossible to overlap and overlap wires in couplings at voltages of
1-5 kV
3-5kV
3-10kV
1-3kV
6-35kV.
What technology significantly speeds up the process of connecting cable cores by about half?
Soldering
Welding
Heat-shrinkable materials made of vulcanized polymers
Electrical taping
Rubber injection molding
How can couplings be safely mounted inside flammable structures without the need for heating, utilizing a unique elastomeric technology?
By wrapping the couplings with fire-resistant fabric
By applying a layer of heat-resistant paint
By using a specialized silicone rubber composition with cold shrinkage
By immersing the couplings in a cooling solution
By coating the couplings with flame-retardant gel
Which feature is forbidden in tips used for switchboards located outside premises due to its adverse effects on joint sealing and metal integrity?
Corrosion coating
Moisture-monitoring hole
Heat material
Transparent casing
Rust screws
How should the formation of bullies, ears, and burrs on sleeves and cores be addressed during the installation process?
Ignoring the imperfections for later correction
Applying additional layers of insulation
Smoothing with small files and grinding treated surfaces
Using abrasive chemicals for cleaning
Leaving the protruding edges of bolts untreated
What is a critical step in preparing AB Cable for installation?
Checking the cable length
Inspecting for visible defects or damages
Testing the cable conductivity
Measuring the cable diameter
Measuring the cable size
Why is it essential to ensure the stability of towers or poles during AB Cable installation?
To increase cable conductivity
To prevent cable sag and expansion
To minimize cable visibility
To reduce the weight of the cable
To maximize cable visibility
What is the initial step required before laying an AB Cable?
Selecting the cable color
Conducting a comprehensive site survey
Testing the cable conductivity
Checking the cable's weight
Chechking the cable size
Why is careful planning and design crucial before installing an AB Cable?
To increase the cable's weight
To comply with local regulations and standards
To determine the cable's color
To measure the cable's flexibility
To determine the cable size
What is the primary focus of the blog post regarding Aerial Bundled Cables (AB Cable)?
Exploring historical uses of AB Cable
Discussing the benefits of AB Cable over underground lines
Highlighting the importance of correct installation techniques
Comparing AB Cable with fiber optic cables
Comparing MCB with fiber optic cables
Why are correct installation techniques crucial for Aerial Bundled Cables (AB Cable)?
To increase the weight of the cables
To enhance the color visibility of the cables
To improve performance, reliability, and longevity
To reduce the conductivity of the cables
To increase reliability
What term describes tunnels housing multiple utilities, including cables, water supply, and heating networks?
Cable conduits
Collectors
Corridors
Channels
Cables
What is the primary benefit of integrating water pipes alongside cables in collectors?
Increasing cable temperature
Decreasing cable humidity
Enhancing cable conductivity
Improving cable visibility
Change the humudity
How would you best describe a cable tunnel?
An open-air structure
A closed corridor with supporting devices
A water treatment facility
A transportation hub
A closed air structure
In which scenarios are cable tunnels and collectors recommended for construction?
Rural areas with sparse development
Urban areas with limited underground utilities
Industrial sites with low energy demand
Cities and enterprises with dense development and many underground utilities
None of above
What are the typical cross-section shapes used for constructing tunnels and collectors?
Triangular and hexagonal
Round and rectangular
Square and oval
Trapezoidal and pentagonal
Oval
How are tunnels of circular cross-section primarily utilized?
For single-sided cable laying
For double-sided cable laying
For water supply only
For ventilation purposes
None of above
What are the minimum height and width requirements for passages between cable structures in tunnels?
Height of 2.0 m, width of 1.5 m
Height of 1.5 m, width of 1.0 m
Height of 1.8 m, width of 1.0 m
Height of 1.0 m, width of 0.5 m
Height of 1.3m, with of 1.0 m
Identify type of signal:
a) harmonic signal
a) noise-like signal of complex shape
a) pulse bipolar
a) unipolar pulse-periodic
a) none of them
Identify type of signal:
a) harmonic signal
a) noise-like signal of complex shape
a) pulse bipolar
a) unipolar pulse-periodic
a) none of them
Determine the symbol
Magnetoelectric device with a movable frame
Magnetoelectric device with a rectifier
The device is magnetostatic with a movable frame
The device is magnetostatic with a closing frame
a) Magnetoelectric device with a closing frame
Determine the symbol
Magnetoelectric device with a movable frame
Magnetoelectric device with a rectifier
The device is magnetostatic with a movable frame.
a) The device is magnetostatic with a closing frame
a) None of them
What is the electrodynamic arrow ammeter for?
The device provides measurement of the current value of the alternating current
The device provides measurement of the current value of the direct current
The device provides measurement of the current value of the resistance
The device provides measurement of the current value of the voltage
The device provides measurement of the current value of the power
Voltage transformer construction
a) Performed in the form of a two-winding step-down transformer.
Performed in the form of a two-winding step-up transformer
a) Performed in the form of a three-winding step-down transformer.
Performed in the form of a three-winding step-up transformer
Performed in the form of a three-winding step-down transformer
Current Transformer construction
Performed in the form of a two-winding step-down transformer
Performed in the form of a two-winding step-up transformer
Performed in the form of a three-winding step-down transformer
Performed in the form of a three-winding step-up transformer
Performed in the form of a three-winding step-down transformer
According to the degree of accuracy, the devices are divided into the following accuracy classes?
0,05 ; 0,1 ; 0,2 ; 0,5 ; 1,0 ; 1,5 ; 2,5 ; 4.0
0.1; 00.1; 1; 1.5; 2; 2.5; 3; 4.
1; 1.5; 2; 2.5
a) Non one
0.1; 0.2; 1; 5
Depending on the magnitude of the electrical resistances are divided how many groups?
3
2
7
4
5
What kind of electrical resistance from 0.1 MOhm and above?
a) Small resistance
a) Large resistance
a) Medium resistance
a) Very high resistance
a) Extra high resistance
Identify the scheme
Electrostatic voltmeter
a) Single phase induction counter
a) Motor
a) Rotor
a) Generator
Depending on the magnitude of the permissible inaccuracy , stationary current transformers are divided into five classes accuracy
0,2; 0,6; 0; 3; 10
0,2; 0,3; 2; 3; 10
0,2; 0,4; 6; 3; 10
a) 0,2; 0,5; 1; 3; 10
0,2; 0,4; 5; 4; 10
Which of the following tools is typically used to measure energy?
a) Voltmeter
a) Wattmeter
a) phase meter
a) frequency meter
a) Ammeter
From 1 ohm to 0.1 MOhm it is:
a) Small resistance
a) Large resistance
a) Medium resistance
a) Very high resistance
a) Extra high resistance
Which of the following tools is typically used to measure current?
a) Ammeter
a) Ohmmeter
a) phase meter
a) wattmeter
a) Voltmeter
Which of the following tools is typically used to measure current frequency?
a) Ohmmeter
a) phase meter
a) frequency meter
a) electric meter
a) Voltmeter
Depending on the magnitude of the electrical resistance are divided how many group?
3
4
2
5
1
What are the types of measuring instruments?
a) Tabular
a) Scale
a) Turnouts
index
a) Scale and Tabular
The principle of operation of induction devices is based on the
magnet
a) magnetic field
a) AC current
a) magnetic flux
a) DC current
Transitional resistances depend on the
a) size of the contact surface
a) purity
Roughness
a) pressing force
a) none of them
What resistance do bad current conductors and insulators have?
Low resistance
a) Large resistances
Medium resistance
a) No resistance
a) High resistance
Measurement of the parameters of electrical circuits is carried out in how many ways?
2
1
3
4
5
Which of the following tools is typically used to measure phase shift angle?
a) Electric meter
a) Ohmmeter
a) Phase meter
a) Frequency meter
a) Voltmeter
Which of the following tools is typically used to measure current frequency?
a) Electric meter
Ohmmeter
a) Phase meter
a) Frequency meter
a) Voltmeter
Which of the following tools is typically used to measure resistance?
Electric meter
Ohmmeter
a) Phase meter
a) Frequency meter
a) Voltmeter
Estimated energy unit?
a) Volt
a) Ohm
a) Watt
a) Kilowatt/hour
a) KVA
The principle of operation of the devices of the electromagnetic system
Is based on the interaction of two coils flowing with electric current
Is based on the interaction of the magnetic field created by the coil with the steel core placed in the field of this coil.
Is based on the same principle, the same as the devices of the electrodynamic system
Is based on the interaction of magnetic fluxes created by current and voltage coils with eddy currents induced by a magnetic field in aluminium disk
a) All answer incorrectly
Depending on the magnitude of the permissible inaccuracy, stationary current transformers are divided into five classes accuracy
0.2; 0.6; 0; 3 and 10
0.2; 0.3; 2; 3 and 10
0.2; 0.4; 6; 3 and 10
0.2; 0.5; 1; 3 and 10
0.2; 0.4; 5; 4 and 10
Depending on the magnitude of the permissible inaccuracy, laboratory current transformers are divided into four classes accuracy
a) 0.01; 0.05; 0.07; 0.1
a) 0.01; 0.05; 0.03; 0.1
a) 0.01; 0.02; 0.05; 0.1
a) 0.01; 0.03; 0.04; 0.1
a) 0.01; 0.05; 0.07; 0.1
Depending on the magnitude of the permissible inaccuracy, stationary voltage transformers are divided into three classes accuracy:
0.2; 1 and 3;
a) 0.5; 1 and 3;
0.5; 2 and 3
0.5; 1 and 4
0.5; 0.1 and 4
The principle of measuring the magnitude of the operating voltage is based on the application of?
a) Ohm’s Law
a) Kirchhoff's law
a) Newton’s laws
a) Coulomb’s Law
a) Faraday’s Law
For how many minutes it is necessary to ground the megohmmeter to remove possible residual charges from it?
a) 1-2 min
a) 2-3 min
a) 5-8 min
a) 10-15 min
a) 1 hour
What is the purpose of documenting electrical measurements and inspection procedures?
To ensure compliance with regulations and safety standards
a) To improve operational efficiency
a) To reduce liability
a) All of the above
a) None of the above
Which device is used to measure the potential difference between two points in an electrical circuit?
a) Ammeter
a) Voltmeter
a) Multimeter
a) Oscilloscope
a) Electricity meter
Which electrical measuring device is used to display the waveforms of electrical signals?
a) Ammeter
a) Voltmeter
a) Multimeter
a) Oscilloscope
a) Electricity meter
