Free Practice Questions for Iran Nezam Electrical Design Exam
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Key Facts: Iran Nezam Electrical Design Exam Exam
60
Total Multiple-Choice Questions on Official Exam
Office of National Building Regulations (inbr.ir)
180 Min
Examination Duration (3 Hours)
inbr.ir Exam Schedule
50%
Minimum Passing Score (After Negative Deduction)
INBR Clause 6-4
-1/3
Negative Marking Penalty per Wrong Answer
IRCEO Exam Regulations
Open Book
Examination Format (Printed Reference Texts Allowed)
inbr.ir Regulations
100 MCQs
Complete Practice Bank with Worked Calculations
OpenExamPrep Practice Bank
The Iran Nezam Electrical Design written paper is a 180-minute, 60-question open-book examination with negative marking (1/3 point deduction per wrong answer) requiring a 50% pass mark administered by inbr.ir, and is followed by a compulsory scientific interview before the pass is confirmed. This independent practice bank features 100 rigorous English-language questions covering Topic 13 distribution, earthing, Topic 3 fire alarms, elevators, energy codes, and lightning protection.
Sample Iran Nezam Electrical Design Exam Practice Questions
Try these sample questions to review concepts for the Iran Nezam Electrical Design Exam exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1A three-phase oil-immersed distribution transformer installed in an indoor building substation has a rated capacity of 800 kVA and a rated secondary voltage of 400 V (line-to-line) at 50 Hz. According to INBR Topic 13 (Clause 13-4), what is the rated secondary full-load line current (In) of this transformer?
2In a balanced three-phase four-wire distribution circuit designed under INBR Topic 13, the copper phase conductors have a cross-sectional area of 70 mm2. Assuming linear loads with negligible harmonic distortion (third harmonic < 15%), what is the minimum permitted cross-sectional area of the copper neutral conductor?
3When designing a three-phase distribution feeder supplying substantial non-linear loads (such as server rooms, LED electronic drivers, and variable frequency drives) where the total third harmonic (triplen harmonic) current exceeds 33% of the fundamental phase current, how must the neutral conductor be sized according to INBR Topic 13?
4According to the official specifications in INBR Topic 13 (1395 edition onwards) and the Iranian national utility standard (TAVANIR), what is the standardized nominal low-voltage supply for three-phase four-wire public distribution networks in Iran?
5An electrical designer is selecting a miniature circuit breaker (MCB) to protect a branch circuit feeding high-inductance equipment, such as control transformers and high-inrush discharge lighting ballasts with starting surges reaching 10 to 14 times rated current. According to Topic 13 and IEC 60898, which instantaneous trip curve must be specified?
6A 630 kVA, 20/0.4 kV three-phase oil distribution transformer has a percentage short-circuit impedance of uk = 4.0%. Assuming an infinite medium-voltage utility bus, what is the prospective symmetrical three-phase short-circuit current (Isc) directly at the 400 V low-voltage secondary terminals?
7According to INBR Topic 13 and IEC 60364-4-43, which mathematical relationship must be strictly satisfied for thermal overload coordination between the circuit design current (Ib), the protective device nominal current rating (In), the continuous cable ampacity (Iz), and the conventional tripping current (I2)?
8A branch circuit is protected by a 16 A Type C miniature circuit breaker (MCB). According to INBR Topic 13 and IEC 60898, what is the minimum prospective fault current required to guarantee instantaneous electromagnetic tripping without any thermal time delay?
9In a low-voltage main distribution board (MDB) designed under INBR Topic 13 and Publication 110, what is the minimum clearance distance in air required between uninsulated, bare active phase busbars of different phases?
10A residential building main switchboard serves 12 identical residential apartments. Each apartment has an individual calculated design active load of 7.0 kW at unity power factor. Applying a standard coincidence/diversity factor (ks) of 0.55 for 12 residential units per INBR Topic 13 guidelines, what is the diversified total active power demand of the building?
About the Iran Nezam Electrical Design Exam Exam
The Iran Construction Engineering Organization (IRCEO / سازمان نظام مهندسی ساختمان) Electrical Design Licensure Examination (آزمون ورود به حرفه مهندسان تأسیسات برقی — صلاحیت طراحی) is the mandatory professional licensing exam in Iran required to obtain independent engineering design and seal privileges (پروانه اشتغال به کار مهندسی پایه ۳ طراحی) for electrical building systems. Supervised by the Ministry of Roads and Urban Development via the Office of National Building Regulations and Building Control (inbr.ir) and administered nationwide by Sazman-e Sanjesh, the test evaluates candidates across the full corpus of Iranian National Building Regulations (مقررات ملی ساختمان). The primary testing focus is INBR Topic 13 (Design and Execution of Electrical Installations in Buildings), supplemented by Topic 3 (Fire Protection), Topic 15 (Elevators and Escalators), Topic 19 (Energy Conservation), Topic 21 (Passive Defense), Management and Planning Organization Publication 110 (نشریه ۱۱۰), and international IEC standards including IEC 60364 and IEC 62305. The written paper is conducted under an open-book (کتابباز) format over 180 minutes with 60 multiple-choice questions and incorporates negative marking (-1/3 point per incorrect response), requiring a net score of at least 50% to qualify. Since the 1404 sittings, candidates who pass the written paper in the design (طراحی) qualification must also pass a compulsory scientific interview (مصاحبه علمی) before the result is confirmed. This practice question bank is an independent English-language multiple-choice study adaptation by OpenExamPrep featuring worked mathematical solutions and code references; it is not an official translation, a simulation of the interview stage, or a released past paper.
Exam sponsor: Office of National Building Regulations and Building Control (inbr.ir), Ministry of Roads and Urban Development; delivered nationwide by the National Organization for Educational Testing (Sazman-e Sanjesh) educational services company. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.
Assessment
Two stages. Stage 1: a written paper of 60 four-option multiple-choice questions covering electrical installations design (Topic 13), fire alarm systems (Topic 3), elevators (Topic 15), energy efficiency (Topic 19), backup generators/UPS (Topic 21), and lightning protection. Stage 2: a compulsory scientific interview (مصاحبه علمی) held at the provincial Roads and Urban Development office, covering the same code sources plus practical use of a design software package chosen by the candidate. Failure or non-attendance at the interview voids the written pass.
Time Limit
180 minutes
Passing Score
50 out of 100 (50%) — clause 6-4 of the official 1405 registration instruction, calculated after the negative-marking deduction
Exam / Certification Fees
Set per sitting and shown in the inbr.ir registration cart; the official 1405 registration instruction does not publish a fixed amount
Exam sponsor websiteFees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.
Our practice resources: topics covered
We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.
Electrical Distribution & Cable Sizing (Topic 13)
Distribution transformers, low-voltage switchboards, MCB/MCCB coordination, busbars, cable current capacity, thermal and grouping derating factors, single-phase and three-phase voltage drop, and short-circuit current calculations.
Earthing & Grounding Systems (Topic 13)
TN-S, TN-C-S, and TT grounding topologies, earth fault loop impedance, RCD selection and tripping coordination, touch and step voltage limits, driven rod, earth plate, and foundation grounding resistance.
Fire Alarm & Emergency Lighting (Topic 3)
Conventional and addressable fire alarm loop architecture, optical smoke and heat detector coverage radius, manual call point positioning, audible alarm levels, fire-rated cabling, and emergency egress lighting.
Lighting Design & Energy Efficiency (Topic 13 & 19)
Lumen method (Zonal Cavity Method), Room Cavity Ratio (RCR), maintained lux levels, UGR glare rating, Lighting Power Density (LPD W/m2) limits, and automatic daylight/occupancy lighting controls.
Backup Power, Elevators & Lightning Protection (Topic 15, 21 & IEC 62305)
Diesel standby generator and UPS battery sizing, elevator feeder and machine room power, rolling sphere method, lightning protection levels (LPL I-IV), and Surge Protective Devices (SPDs).
Preparing for the Iran Nezam Electrical Design Exam Exam
What You Need to Know
- Passing score: 50 out of 100 (50%) — clause 6-4 of the official 1405 registration instruction, calculated after the negative-marking deduction
- Assessment: Two stages. Stage 1: a written paper of 60 four-option multiple-choice questions covering electrical installations design (Topic 13), fire alarm systems (Topic 3), elevators (Topic 15), energy efficiency (Topic 19), backup generators/UPS (Topic 21), and lightning protection. Stage 2: a compulsory scientific interview (مصاحبه علمی) held at the provincial Roads and Urban Development office, covering the same code sources plus practical use of a design software package chosen by the candidate. Failure or non-attendance at the interview voids the written pass.
- Time limit: 180 minutes
- Exam / certification fees: Set per sitting and shown in the inbr.ir registration cart; the official 1405 registration instruction does not publish a fixed amount Official sources
Using Our Practice Resources
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Iran Nezam Electrical Design Exam: Suggested Study Strategy
Frequently Asked Questions
What is the format and duration of the Iran Nezam Electrical Design examination?
The exam consists of 60 four-option multiple-choice questions held over 180 minutes (3 hours). It is conducted open-book (کتابباز), meaning candidates are permitted to bring official printed building code texts, standards, and approved calculators into the examination hall.
How is negative marking applied on the Nezam Mohandesi exam?
Negative marking is strictly enforced: every incorrect answer deducts 1/3 of a point (0.333 marks). Three incorrect answers negate one correct answer. The net percentage is calculated as: Net Score = [(Correct - (Incorrect / 3)) / Total Questions] * 100%. A minimum net score of 50.0% is required to pass.
What are the primary official references for the Electrical Design exam?
The core references are INBR Topic 13 (طرح و اجرای تأسیسات برقی ساختمانها), Topic 3 (حفاظت ساختمانها در مقابل حریق), Topic 15 (آسانسورها و پلههای برقی), Topic 19 (صرفهجویی در مصرف انرژی), Topic 21 (پدافند غیرعامل), and Publication 110 of the Plan and Budget Organization (نشریه ۱۱۰ سازمان برنامه و بودجه), alongside IEC 60364 and IEC 62305.
Is this practice question bank an official publication of inbr.ir or IRCEO?
No. This question bank is an independent English-language pedagogical study adaptation developed by OpenExamPrep. It is not an official translation, past-paper publication, or endorsement by the Ministry of Roads and Urban Development, IRCEO, or Sazman-e Sanjesh.
What experience is required to sit for the Grade 3 Electrical Design licensure exam?
Candidates must hold an accredited engineering degree in Electrical Engineering and have completed at least 3 years of verified practical experience for Bachelor's (B.Sc.) degree holders, 2 years for Master's (M.Sc.) holders, or 1 year for Ph.D. holders following their graduation date.