Building Construction (Electrical Systems)
Questions and Answers
- 1.
Form of energy generated by friction, induction or chemical change, having magnetic, chemical and radiant effect. The motion of free electrons through a solid conductor.
Explanation
Electricity is the correct answer because it is a form of energy that can be generated through friction, induction, or chemical change. It has magnetic, chemical, and radiant effects. Additionally, the motion of free electrons through a solid conductor is a characteristic of electricity.Rate this question:
- 2.
Combination of two or more electric cells capable of storing and supplying direct current.
Explanation
A battery is a combination of two or more electric cells that have the ability to store and provide direct current. It is a portable power source commonly used in various electronic devices such as smartphones, laptops, and cars. The cells within a battery work together to convert chemical energy into electrical energy, which can then be used to power these devices.Rate this question:
- 3.
Battery that delivers electricity as soon as its parts are assembled, provided that it is connected to a circuit.
Explanation
Primary batteries are designed to deliver electricity as soon as their parts are assembled and connected to a circuit. They do not require any additional charging or external power source to function. Therefore, the correct answer is "primary batteries," "primary battery," and "primary."Rate this question:
- 4.
Battery that has electricity from some external source must be passed through it before it can deliver an electric current.
Explanation
The given answer options are all related to batteries. "Secondary batteries" refers to batteries that can be recharged, while "secondary battery" is another term for the same concept. "Secondary" alone can also refer to these types of batteries. "Storage battery" is another term used to describe batteries that store electrical energy. "Storage" alone can also refer to this type of battery.Rate this question:
- 5.
Machine that converts mechanical energy into electrical energy.
Explanation
A generator is a machine that converts mechanical energy into electrical energy. It does this by using a rotating coil of wire, known as an armature, within a magnetic field. As the armature spins, it induces a current in the wire due to the magnetic field. This current is then collected and used as electrical energy. Generators are commonly used in power plants and other applications where a reliable source of electricity is needed.Rate this question:
- 6.
AC
Explanation
AC stands for alternating current. Alternating current is an electric current that periodically reverses direction. It is commonly used in homes and businesses to power electrical devices. Unlike direct current (DC), which flows in only one direction, AC changes direction at regular intervals. This allows for the efficient transmission of electricity over long distances and the ability to easily transform voltage levels.Rate this question:
- 7.
DC
Explanation
DC stands for direct current. Direct current is a type of electric current that flows in one direction only, without changing its magnitude or direction. It is commonly used in batteries and electronic devices. Unlike alternating current (AC), which periodically changes direction, direct current remains constant.Rate this question:
- 8.
Circular raceways used to enclose wires and cable and are of metal or plastic
Explanation
The circular raceways used to enclose wires and cables are called conduits. They can be made of either metal or plastic. Conduits provide protection and organization for the wires and cables, preventing them from being damaged or tangled. They also help to route and hide the wires, improving the overall aesthetic of the installation.Rate this question:
- 9.
Channels or wiring accessories used for holding wires, cables, bus bars.
Explanation
Raceways are channels or wiring accessories that are used for holding wires, cables, and bus bars. They provide a protective enclosure for electrical wiring, ensuring that it is organized and safely contained. Raceways can be made of various materials such as metal or plastic and are commonly used in both residential and commercial settings to route and protect electrical wiring. They help to prevent damage to the wires, provide easy access for maintenance or repairs, and ensure compliance with electrical codes and safety regulations.Rate this question:
- 10.
Wiring device into which the utilization equipment cord is plugged into.
Explanation
A receptacle is a wiring device into which the utilization equipment cord is plugged into. It provides a connection point for electrical devices to receive power from the electrical system.Rate this question:
- 11.
Device for making, breaking, or changing conditions in an electrical circuit under the conditions of load.
Explanation
A switch is a device used to control the flow of electricity in a circuit. It can be used to make or break the circuit, allowing or preventing the flow of current. It can also be used to change the conditions in the circuit, such as turning on or off a light or appliance. Switches are commonly found in homes and buildings to control the lighting and electrical devices. They are essential for the safe and efficient operation of electrical systems.Rate this question:
- 12.
Coverings for switches and wall outlets made of metal or of phenolic compound.
Explanation
Wall plates and face plates are both coverings for switches and wall outlets. They can be made of different materials such as metal or phenolic compound. These plates are used to provide a protective and decorative covering for the electrical components in a wall.Rate this question:
- 13.
Melts if there is any current that would be dangerous to the circuit.
Explanation
A fuse is a safety device that is designed to protect an electrical circuit from excessive current. When there is a current that exceeds the rated value of the fuse, it melts and breaks the circuit, preventing any further flow of current. This is important because excessive current can damage the circuit or even cause a fire. Therefore, the purpose of a fuse is to ensure the safety of the circuit by melting if there is any current that would be dangerous.Rate this question:
- 14.
Protective device designed to function as a switch
Explanation
A circuit breaker is a protective device designed to function as a switch. It is used to protect electrical circuits from overloads or short circuits by automatically interrupting the flow of current when a fault is detected. When a fault occurs, the circuit breaker trips and opens the circuit, preventing further damage to the electrical system. It acts as a safety mechanism to prevent electrical fires and protect electrical equipment from damage.Rate this question:
- 15.
Box wherein the protective devices are housed from which the circuits and busbars terminate.
Explanation
A panelboard is a box or enclosure that contains protective devices such as circuit breakers or fuses. It is where the circuits and busbars terminate, meaning that the electrical connections and wiring from various circuits come together in the panelboard. The panelboard acts as a central hub for distributing and controlling electricity within a building or facility. It provides a convenient and organized location for accessing and managing the electrical system.Rate this question:
- 16.
Auxiliary power station where electrical current is converted or where voltage is stepped up or down.
- A.
Service drop
- B.
Substation
- C.
Transformer vault
- D.
Line drop
Correct Answer
B. SubstationExplanation
A substation is an auxiliary power station where electrical current is converted or where voltage is stepped up or down. It is a crucial component of the electrical grid, acting as a distribution point for electricity from power plants to consumers. Substations help regulate the flow of electricity, ensuring that it is delivered at the appropriate voltage levels for safe and efficient use. They also play a role in monitoring and controlling the power supply, allowing for quick response to any issues or outages.Rate this question:
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- 17.
Underground portion of service conductors extending from a main power line or transformer to a building.
- A.
Service lateral
- B.
Substation
- C.
Feeder
- D.
Service drop
Correct Answer
A. Service lateralExplanation
A service lateral refers to the underground portion of service conductors that connect a main power line or transformer to a building. This means that it is responsible for delivering electricity from the main power source to a specific building. Unlike a service drop, which refers to the overhead portion of service conductors, a service lateral is located underground. Therefore, the correct answer is service lateral.Rate this question:
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- 18.
Meter for measuring and recording the quantity of electric power consumed with respect to time
- A.
Service entrance conductor
- B.
Service
- C.
Watt-hour meter
- D.
Uninterruptible power supply
Correct Answer
C. Watt-hour meterExplanation
A watt-hour meter is a device used to measure and record the quantity of electric power consumed with respect to time. It is commonly used to measure the amount of energy consumed by electrical appliances or systems. The meter calculates the total energy usage by multiplying the power consumption in watts by the time in hours. This information is important for monitoring and billing purposes, as well as for evaluating energy efficiency and managing electricity consumption.Rate this question:
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- 19.
Pertaining to a circuit in which alternating current below 50 volts is supplied by a step-down transformer from the normal line voltage used in residential systems. do not require a protective raceway.
- A.
Low-voltage
- B.
Distribution panel
- C.
High-voltage
- D.
Mid-voltage
Correct Answer
A. Low-voltageExplanation
In residential systems, the normal line voltage is typically higher than 50 volts. However, in a circuit where the alternating current is below 50 volts, it is considered low-voltage. In such cases, a step-down transformer is used to reduce the voltage from the normal line voltage to below 50 volts. Since the voltage is low, the circuit does not require a protective raceway. Therefore, the correct answer is "low-voltage".Rate this question:
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- 20.
Branch circuit that supplies current in a number of outlets for lighting and appliances.
Correct Answer
general purposeExplanation
A general purpose branch circuit refers to a circuit that is designed to supply current to a variety of outlets for both lighting and appliances. This type of circuit is commonly used in residential and commercial buildings to provide power to multiple devices and fixtures throughout the space. It is called "general purpose" because it is not dedicated to a specific type of equipment or function, but rather serves a broad range of electrical needs within the building.Rate this question:
- 21.
Branch supplies current in one or more outlets specifically intended for appliances.
Correct Answer
applianceExplanation
An appliance refers to a device or machine that is designed to perform a specific task or function. In the context of the question, the branch supplies current to one or more outlets that are specifically intended for these appliances. This suggests that the branch is responsible for providing electrical power to the appliances, allowing them to function properly.Rate this question:
- 22.
Branch circuit that supplies current only to a single piece of electrical equipment.
Correct Answer
individual circuitExplanation
An individual circuit refers to a branch circuit that supplies current exclusively to a single piece of electrical equipment. This means that the circuit is dedicated solely to powering a specific device or appliance, ensuring that it receives a consistent and uninterrupted flow of electricity. By using individual circuits, electrical equipment can be isolated from other devices, preventing any potential power fluctuations or overloads caused by sharing a circuit with multiple appliances.Rate this question:
- 23.
Metal that is most preferred in all conductor types
Correct Answer
copperExplanation
Copper is the most preferred metal in all conductor types because it has excellent electrical conductivity. It allows electricity to flow easily through it, making it efficient for conducting electricity. Copper also has good thermal conductivity, meaning it can effectively transfer heat. Additionally, copper is highly ductile and malleable, making it easy to shape into wires for various applications. Its corrosion resistance and durability further contribute to its popularity as a conductor material.Rate this question:
- 24.
Smallest wire permitted.
- A.
21
- B.
11
- C.
14
- D.
13
Correct Answer
C. 14Explanation
The correct answer is 14. This can be determined by comparing the given numbers and selecting the smallest one. In this case, 14 is the smallest number among the options provided.Rate this question:
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- 25.
Large conductors which are not circular in cross section and are usually found only to supply the main switch boards.
- A.
Wires
- B.
Bus bars
- C.
Cables
- D.
Stranded wire
Correct Answer
B. Bus barsExplanation
Bus bars are large conductors that are not circular in cross section and are typically used to supply main switchboards. Unlike wires, cables, and stranded wires, bus bars are designed to carry high currents and provide a low-resistance path for electrical power distribution. They are commonly found in industrial settings and power distribution systems where large amounts of electricity need to be transferred efficiently.Rate this question:
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- 26.
Consists of a group of wires twisted to form a metal string.
- A.
Stranded wire
- B.
Cord wire
- C.
Solid wire
- D.
Copper wire
Correct Answer
A. Stranded wireExplanation
A stranded wire is made up of multiple smaller wires twisted together to form a larger, flexible wire. This design allows for increased flexibility and durability compared to a solid wire. The twisted configuration also helps to prevent the wire from breaking or fraying easily. Therefore, a stranded wire is the most suitable option among the given choices for a group of wires twisted to form a metal string.Rate this question:
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- 27.
Artificial area measurement, representing the square of the cable diameter when the diameter is expressed in mils.
- A.
MCM
- B.
MIL
- C.
Diameter mil
- D.
Circular mil
Correct Answer
D. Circular milExplanation
Circular mil is a unit of measurement used to represent the area of a circle with a diameter expressed in mils. It is commonly used in electrical engineering to measure the cross-sectional area of wires and cables. The circular mil value is calculated by squaring the diameter of the cable in mils. This measurement is useful for determining the current carrying capacity and resistance of wires.Rate this question:
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- 28.
Electric cable consisting of a tubular copper sheath containing one or more conductors embedded in a highly compressed insulating refractory material
- A.
Mineral insulated cable
- B.
Armored cable
- C.
Coaxial cable
- D.
Non metallic sheathed cable
Correct Answer
A. Mineral insulated cableExplanation
A mineral insulated cable is made up of a tubular copper sheath that contains one or more conductors. These conductors are embedded in a highly compressed insulating refractory material. This type of cable is commonly used in applications where high temperature resistance and fire protection are required, such as in industrial and commercial buildings. The highly compressed insulating material provides excellent insulation and protection for the conductors, while the copper sheath offers additional strength and durability.Rate this question:
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- 29.
Cable for transmitting high-frequency telephone, digital or television signals.
- A.
Mineral insulated cavle
- B.
Non metallic sheathed cable
- C.
Armored cable
- D.
Coaxial cable
Correct Answer
D. Coaxial cableExplanation
A coaxial cable is the correct answer because it is specifically designed for transmitting high-frequency signals such as telephone, digital, or television signals. Unlike other options like mineral insulated cable, non-metallic sheathed cable, or armored cable, coaxial cable has a central conductor surrounded by an insulating layer, a metallic shield, and an outer insulating layer. This design allows for efficient transmission of high-frequency signals while minimizing interference and signal loss.Rate this question:
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- 30.
EMT
Correct Answer
electric metal tubingExplanation
EMT stands for electric metal tubing. It is a type of conduit used in electrical installations to protect and route electrical wiring. EMT is made of metal, usually steel, and is commonly used in residential and commercial buildings. It provides a rigid and durable pathway for electrical wires, ensuring their protection and preventing damage. EMT is often preferred for its ease of installation, affordability, and ability to withstand physical stress.Rate this question:
- 31.
Switches intended for frequent interrupting
- A.
Normal
- B.
Heavy duty
- C.
Light
- D.
All of the above
Correct Answer
B. Heavy dutyExplanation
The term "heavy duty" refers to switches that are designed to handle frequent interrupting or switching of electrical currents. These switches are built to withstand high levels of electrical load and are often used in industrial or commercial settings where there is a need for continuous and reliable operation. Therefore, the correct answer is "heavy duty" as it specifically addresses switches intended for frequent interrupting.Rate this question:
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- 32.
A double throw switch, essential part of an emergency or standby service. On failure of normal power, emergency service is automatically applied
- A.
Automatic transfer switch
- B.
Automatic transformer switch
- C.
Automated transfer switch
- D.
Air transfer switch
Correct Answer
A. Automatic transfer switchExplanation
An automatic transfer switch is an essential part of an emergency or standby service. It is used to automatically transfer power from the normal source to the emergency source in case of a failure in the normal power supply. This ensures that the emergency service is immediately applied without any interruption, providing a seamless transition between power sources.Rate this question:
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- 33.
Under the ceiling raceways composed of header ducts and distribution ducts separate for power and telephone cabling
- A.
Prewired ceiling distribution systems
- B.
Underfloor ducts
- C.
Ceiling raceway systems
- D.
None of the above
Correct Answer
C. Ceiling raceway systemsExplanation
Ceiling raceway systems are the correct answer because they consist of header ducts and distribution ducts that are used to separate power and telephone cabling. These systems are installed under the ceiling and provide a convenient and organized way to route and manage cables. Prewired ceiling distribution systems and underfloor ducts are not mentioned in the given explanation, so they are not the correct answer.Rate this question:
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- 34.
Factory assembled channel with conductors for one to four circuits permanently installed in the track that will act as light duty plug-in buswasy.
- A.
Cable tray
- B.
Flat cable
- C.
Armored cable wiring
- D.
Lighting track
Correct Answer
D. Lighting trackExplanation
A lighting track is a factory assembled channel with conductors for one to four circuits permanently installed in the track. It is designed to act as a light duty plug-in busway. This means that it provides a convenient and flexible way to distribute power to lighting fixtures, allowing them to be easily plugged in and moved as needed. Unlike cable trays, flat cables, and armored cable wiring, a lighting track specifically caters to lighting needs and offers a more adaptable and user-friendly solution for lighting installations.Rate this question:
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- 35.
A rheostat or similar device for regulating the intensity of an electric light without appreciably affecting spatial distribution.
- A.
Momentary contact switch
- B.
Three way switch
- C.
Dimmer tray
- D.
Four way switch
Correct Answer
C. Dimmer trayExplanation
A dimmer tray is a device used to regulate the intensity of an electric light without significantly affecting its spatial distribution. It allows for adjusting the brightness of the light source to create the desired ambiance or lighting level in a room or space. Unlike other options listed, such as a momentary contact switch or three-way switch, a dimmer tray specifically focuses on controlling the intensity of the light rather than simply turning it on or off or changing its direction.Rate this question:
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- 36.
Give the (3) classifications of switches according to intensity of use.
- 37.
Give the (3) types of floor raceways recognized by the NEC.
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