Electrical Theory
What happens to the resistance of a wire when its length is increased and its cross-sectional area is decreased?
It will increase.
What is the primary purpose of the National Electrical Code?
Safeguarding persons and property from hazards arising from the use of electricity.
A handy box is a special variant of what type of box?
Single-gang box.
Which type of conduit body is Type LB?
Which type of conduit body is Type LB?
What size wires are stranded when installed in conduit but may be solid when used for grounding and bonding?
No. 8 AWG or larger.
If three 150-ohm resistors are connected in parallel, and that combination is connected in series with two 100-ohm resistors, what is the total resistance?
250 ohms.
How often is the National Electrical Code updated?
Every 3 years.
According to NEC guidelines, what is the maximum number of grounding conductors inside an electrical box that can be counted as a single conductor?
4 grounding conductors.
Which type of conduit is most common for metal stud environments?
EMT.
Which NEC table is used to determine the maximum ampacity for single-insulated conductors?
NEC Table 310.19.
Which instrument is used for resistance measurement?
Ohmmeter.
What chapter of the NEC covers Article 315?
Chapter 3.
What is the minimum distance between two raceway entries, sized 4 inches and 6 inches, that enclose the same conductor at an angle on a junction box?
36 inches.
What fitting is used in a wireway system where circuit conductors may branch in different directions?
Tee fitting.
What is the letter code for heat-resistant thermoplastic conductor insulation?
THHN.
What is the correct formula for finding total resistance of two resistors connected in parallel?
RT = R1 × R2 / R1 + R2.
According to the NEC, what hazardous area classification is assigned to grain handling and storage plants?
Class II.
After cutting EMT conduit, which tool is required to perform the next step?
Hand reamer.
Which NEC section contains provisions for using steel and aluminum cable tray systems as an equipment grounding conductor?
NEC Section 392.60(B).
What is the danger of using high-stretch rope for pulling cable?
It stores potential energy that can be suddenly unleashed.
If current does not divide anywhere while tracing the path through a bulb circuit, what type of circuit is it?
Series circuit.
Which Informative Annex of the NEC provides information about SCADA systems?
Informative Annex G.
Which NEC section covers uses not permitted for EMT?
NEC Section 358.12.
What are commonly used for storing conduit?
Pipe racks.
What is the minimum amount of free conductor required by NEC Section 300.14 for connections to wiring devices or splices?
6 inches.