Questions and Answers
What is a slender filament of drawn metal?
wire
The purpose of the conductor is to furnish a path for the flow of electrons.
True
Conductance is the ease with which a material will conduct electricity.
ease
A good conductor is a material that will contain many what?
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A conductor is a single wire or combination of strands of wire not insulated from one another and capable of carrying an electrical current.
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There is no perfect conductor, as all materials offer some opposition to the electron flow.
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310.106(C) of the NEC generally requires that conductors, where they are installed in raceways, shall be stranded when the conductor size is what or larger?
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Steel conduit will conduct electricity.
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A hard-drawn solid copper conductor will have what kind of tensile strength compared to a soft-drawn copper conductor?
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What is the title of Article 310 of the NEC?
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Which of the following is not a metal material recognized by the Code in 310.106(B) for electrical conductors?
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According to 110.5, when the Code refers only to a conductor size and the material of the conductor is not specified, the Code intends the use of what?
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Aluminum conductors are terminated in a switch with the use of copper lugs. According to 110.14, this is generally a violation.
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The cross-sectional area of a solid, copper-clad aluminum conductor must contain a minimum of what percentage of copper?
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Table 310.106(A) establishes the minimum size copper conductor generally permitted to be used for a 120-volt lighting circuit as what AWG for copper and what AWG for aluminum?
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Steel conduit may be used as an equipment grounding conductor as it is capable of conducting electrons under fault conditions.
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A stranded conductor used as a single conductor is often referred to as a what?
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A multiple conductor cable is a combination of two or more insulated conductors under a common jacket.
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Ohm/kFT, as used in Table 8, means ohms per one thousand feet. Table 8 has a different resistance listing for a solid and a stranded 10 AWG copper conductor.
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What is the resistance of a stranded, 8 AWG copper conductor compared to a solid conductor?
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How many strands of wire are used in the makeup of a 6 AWG stranded conductor?
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How many strands of wire are used in the makeup of a 1 AWG stranded conductor?
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How many strands of wire are used in the makeup of a 4/0 AWG stranded conductor?
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How many strands of wire are used in the makeup of a 500 kcmil stranded conductor?
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What is the resistance per 1,000 feet of 8 AWG copper uncoated, stranded conductors?
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What is the resistance per 1,000 feet of 8 AWG aluminum stranded conductors?
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Study Notes
Conductors and Wiring
- A wire is a slender filament of drawn metal used in electrical applications.
- Conductors provide a path for electron flow; they are essential in electrical circuits.
- Conductance refers to how easily a material allows electricity to flow, known as its ease of conduction.
- A good conductor is characterized by having many free electrons that facilitate current flow.
Types of Conductors
- A conductor can be a single wire or multiple strands, uninsulated, capable of carrying electric current.
- Perfect conductors do not exist; all materials present some opposition to electron flow, known as resistance.
- Steel conduit can conduct electricity and may serve as an equipment grounding conductor under fault conditions.
Conductivity Properties
- Copper conductors have a higher tensile strength compared to aluminum conductors.
- The NEC specifies that conductors in raceways should be stranded if they are 8 AWG or larger.
- Copper is typically used for conductor sizing when no material is specified in the NEC.
NEC Regulations
- Article 310 of the NEC is titled "Conductors for General Wiring".
- Not all metals are accepted under NEC guidelines for conductors; silver is one such material not recognized in 310.106(B).
- Aluminum conductors connected to copper lugs in switches is usually considered a violation according to NEC regulations.
Conductor Composition
- The cross-sectional area of a solid copper-clad aluminum conductor must consist of at least 10% copper.
- The minimum size for a copper conductor in a 120-volt lighting circuit is designated as 14 AWG for copper and 12 AWG for aluminum.
Stranded vs Solid Conductors
- Stranded conductors, used individually, are referred to as cables and can improve flexibility.
- The makeup of stranded conductors consists of multiple strands; for example:
- 6 AWG stranded conductor contains 7 strands.
- 1 AWG stranded conductor contains 19 strands.
- 4/0 AWG stranded conductor also has 19 strands.
- 500 kcmil stranded conductor consists of 37 strands.
Resistance Values
- The resistance of conductors is critical in electrical equations. For example:
- The resistance of 8 AWG copper stranded conductors is 0.778 ohms per 1,000 feet.
- The resistance of 8 AWG aluminum stranded conductors is 1.28 ohms per 1,000 feet.
- There are differences between solid and stranded conductors; stranded conductors typically exhibit higher resistance than solid counterparts.
Special Considerations
- Silver is noted for being a superior conductor compared to copper, but precautions are necessary with silver-plated contacts due to potential fragility.
- The NEC Table 8 addresses the resistance properties and features significant variations between solid and stranded versions of the same gauge.
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Description
Test your knowledge on conductors and wiring concepts. This quiz covers the properties of various conductors, types of wiring, and essential electrical principles related to conductance and resistance. Perfect for students studying electrical engineering or related fields.
