Electrician Workbook Basic Electrical

A kilowatt (kW) is a unit of power equal to 1,000 watts. It is commonly used to measure the rate at which electrical energy is consumed or produced.

A junction box is an enclosure used to house and protect electric wires or cables that are joined together in connecting or branching electric circuits. It provides a safe and organized space for electrical connections, preventing damage and ensuring proper insulation. The use of a junction box helps to maintain the integrity and functionality of the electrical system by keeping the wires secure and protected from external elements.

Conductivity is a measure of how well a substance can conduct electric current. It is equal to the reciprocal of the resistivity of the substance. In other words, the higher the conductivity, the better the substance can conduct electricity. It is also known as specific conductance.

Resistance is the correct answer because it refers to the opposition of a conductor to the flow of current. When there is resistance in a circuit, some of the electric energy is transformed into heat. Resistance is usually measured in ohms. Ampere (A) and amperage refer to the unit of electric current, while ohm is the unit of resistance. Therefore, resistance is the most appropriate term to describe the given explanation.

A coaxial cable is a type of cable that is used to transmit high-frequency signals, such as those used in telephone, digital, or television applications. It consists of an insulated conducting core, which is surrounded by a metallic shield and then covered with a protective outer layer. The metallic shield helps to minimize interference and signal loss, making it ideal for transmitting high-frequency signals over long distances. Therefore, the correct answer is COAXIAL CABLE.

Flexible metal conduit is a type of conduit that is helically wound and made of metal. It is used for making connections to motors or other vibrating equipment. It is also commonly known as Greenfield conduit. This type of conduit is flexible, allowing it to easily bend and maneuver around obstacles. It provides protection for the electrical wiring inside and is suitable for applications where vibration or movement is a concern. Rigid metal conduit, on the other hand, is a more rigid and less flexible type of conduit. Therefore, the correct answer is flexible metal conduit.

The correct answer is "WATT (W)". The question is asking for the SI unit that is equal to one joule per second or to the power represented by a current of one ampere flowing across a potential difference of one volt. The unit for power is the watt, which is equal to one joule per second.

The breakdown voltage refers to the minimum applied voltage that causes an insulator to break down and allows current to pass through it. This phenomenon is commonly observed in dielectric materials, which are used to insulate electrical components. When the applied voltage exceeds the breakdown voltage, the insulator's resistance decreases, leading to the flow of current. Junction box and grommet are unrelated terms and do not describe the given concept.

The basic SI unit of electric current is the ampere (A). It is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied to one ohm of resistance. Ampere is commonly used to measure the amount of electric current flowing through a circuit.

An armored cable is an electric cable that has two or more insulated conductors protected by a flexible, helically wound metal wrapping. This metal wrapping provides extra protection to the conductors, making the cable more resistant to physical damage and external elements. It is commonly used in applications where the cable needs to be installed in areas with a higher risk of damage, such as underground or in industrial environments. The term "BX" is another name for armored cable.

Amperage refers to the strength of an electric current, which is measured or expressed in amperes. It is analogous to the rate of water flow, meaning that just as water flow can be measured in terms of how much water passes through a point in a given time, amperage measures the amount of electric charge that passes through a point in a circuit per unit of time. In other words, amperage quantifies the flow of electric charge in a circuit, similar to how water flow quantifies the movement of water.

The correct answer is ELECTROMOTIVE FORCE (emf). Electromotive force refers to the energy per unit charge available for conversion from one form of energy to electrical energy or vice versa. It is commonly associated with batteries, generators, and motors, where chemical, mechanical, or other forms of energy are converted into electrical energy. It is measured in volts (V) and represents the potential difference or voltage across a circuit.

A cable tray is an open metal framework that is used to support and organize insulated electrical conductors. It provides a safe and efficient way to route and manage cables in various settings, such as industrial buildings, data centers, and commercial facilities. Cable trays are designed to prevent cable damage and ensure proper ventilation for the cables, reducing the risk of overheating. They are a cost-effective solution for cable management and are easily adjustable and expandable to accommodate future cable additions or modifications.

A shielded cable is an electric cable that is enclosed within a metallic sheath. This metallic sheath acts as a shield and helps to reduce the effects of external electric or magnetic fields. By providing this shielding, the cable is protected from interference and can transmit signals more effectively without any distortion or loss of quality. Shielded cables are commonly used in applications where there is a need to minimize the impact of external electromagnetic interference, such as in audio or video transmission, computer networking, or industrial automation.

The correct answer is "Moisture and heat resistance rubber". This suggests that the material being referred to has properties that make it resistant to both moisture and heat. It is likely that this type of rubber can withstand exposure to high temperatures without degrading or losing its structural integrity, while also being resistant to the damaging effects of moisture or water.

The correct answer is COULOMB (C). The explanation is that the coulomb is the SI unit of electric charge. It represents the quantity of electricity transferred along a conductor by a current of one ampere in one second. This unit is used to measure the amount of charge in an electrical system or the flow of charge in an electric circuit.

The potential difference or electromotive force is expressed in volts. This is analogous to the pressure in water flow. Just like pressure is the driving force for water to flow, voltage is the driving force for electric current to flow. It represents the difference in electric potential between two points in a circuit and determines the flow of electrons.

The correct answer is "WIRE" because it is a pliable metallic strand or twisted or woven assembly of such strands. It is often insulated with a dielectric material and used as a conductor of electricity.

A grommet is a rubber or plastic washer that is inserted in a hole in a metal part. It is used to prevent grounding of a wire passing through the hole. The grommet acts as insulation, protecting the wire from coming into contact with the metal and causing a short circuit or electrical shock.

The correct answer is WATTAGE. Wattage refers to the amount of power, specifically the power needed to operate an electrical device or appliance, and is typically measured in watts.

The correct answer is ELECTRICAL METAL TUBING (EMT). EMT is a type of conduit that is made of thin-walled, tubular steel. It is joined together using compression or setscrew couplings. EMT is commonly used in electrical installations to protect and route electrical wiring. It is a flexible and lightweight option compared to rigid metal conduit, making it easier to install.

The correct answer is MINERAL ISULATED CABLE because it accurately describes an electric cable consisting of a tubular copper sheath containing one or more conductors embedded in a highly compressed, insulating refractory mineral. This type of cable is commonly used in high temperature and fire-resistant applications due to its ability to withstand extreme conditions.

An outlet box is the correct answer because it is specifically designed to house electrical outlets and provide a safe and secure connection point for electrical cables. It is commonly used in residential and commercial buildings to contain and protect electrical wiring connections. The other options mentioned (utility box, pull box, and cut out box) may have different purposes or functions, but they are not specifically designed for housing electrical outlets.

Dielectric strength refers to the maximum voltage that can be applied to a given material without causing it to breakdown. It is usually expressed in volts or kilovolts per unit of thickness. This property is important in electrical insulation as it determines the ability of a material to withstand high voltages without experiencing electrical breakdown.

Joule's Law states that the rate of production of heat by direct current is directly proportional to the resistance of the circuit and to the square of the current. This means that as the resistance of the circuit increases, the rate of heat production also increases. Similarly, as the current in the circuit increases, the rate of heat production increases even more. This principle is important in understanding how electrical energy is converted into heat energy in various electrical devices and circuits.

The correct answer is "Moisture & heat resistant thermoplastic" because it is the only option that specifically mentions both moisture and heat resistance. The other options either only mention moisture resistance or do not mention resistance to either moisture or heat. Therefore, the moisture & heat resistant thermoplastic is the most suitable material for applications where both moisture and heat resistance are required.

Insulators are commonly used as supports and for additional protection for wires. They are materials that do not conduct electricity, and therefore prevent the flow of electrical current. In the context of the given options, an insulator would be the most suitable choice for providing support and protection for wires, as it would prevent any potential electrical hazards. The other options, such as cut out box, outlet box, and bushing, do not specifically serve the purpose of insulation and may not provide the same level of protection for the wires.

The correct answer is "Moisture & heat resistant cross linked". Cross linked refers to the process of chemically bonding the polymer chains together, making the material more durable and resistant to heat and moisture. This type of material is commonly used in applications where high temperatures and exposure to moisture are expected, such as electrical wiring and insulation.

A multi-outlet assembly is a surface mounted raceway designed to house the electrical wires for a circuit and a series of receptacles. This means that it is a convenient and organized solution for providing power to multiple devices in a specific area. The multi-outlet assembly allows for easy installation and maintenance of the electrical wiring, while also providing a safe and secure housing for the wires and receptacles.

A cut out box is a type of metal box with a hinge and enclosure that is commonly used to house electrical components such as fuses or circuit breakers. It is often installed on the exterior of a building and provides a secure and protected space for these components. The other options mentioned, such as outlet box, pull box, and utility box, are also types of metal boxes used in electrical installations, but they do not typically have a hinge and enclosure like a cut out box does. Therefore, the correct answer is cut out box.