MV-517 · Practice

MV Question Bank & Practice Exams

788 questions written to match the 16 MV labs, from first principles to expert design checks. Every question has the reasoning and a standard reference. Pick a module, a level and your region, then practise one at a time or sit a timed exam. Your progress stays on this device.

In short

788 questions across all 16 MV modules, about 50 per module.
Three levels: Beginner (concepts), Practitioner (design and site practice), Expert (calculations and edge cases).
Regional questions for the GCC, Saudi Arabia, Australia, New Zealand and Asia, plus general IEC/IEEE content.
Two modes: practice with instant explanations, or a timed exam (72 seconds per question, 70% pass mark) with a full review.
Free to download as CSV or JSON for training teams, with attribution to MEPVirtual.

By Eng. Mannan Maqsood, Electrical EngineerPart of the MV Hub

Practice Interactive

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Region filter keeps general questions and adds the ones for your region. Keyboard: A to D or 1 to 4 to answer, Enter for next.

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Green is correct, red is answered but wrong. Click a module code to practise it.

Sample questions by module

A few questions from each module with answers. Open the lab to learn the topic, then come back and practise the full set.

MV-501 MV Systems & Network Explorer 48 questions

What voltage range is usually called medium voltage in distribution? Answer: Above 1 kV up to about 36 kV
Why is electricity transmitted at high voltage? Answer: Lower current means much lower I²R losses
What does a closed ring need at every substation to avoid outages for a single cable fault? Answer: Circuit breakers with unit protection

MV-502 MV Cables & Accessories Lab 47 questions

What is the job of the semiconducting conductor screen? Answer: Smooth the electric field around the strands
What is the nominal XLPE insulation thickness for an 11 kV (6.35/11 kV) cable? Answer: 3.4 mm
Which standard is the reference method for cable current rating? Answer: IEC 60287

MV-503 RMU & MV Switchgear Lab 49 questions

What does RMU stand for? Answer: Ring Main Unit
In a CCF RMU, what does F stand for? Answer: Fuse-switch combination
Which standard covers switch-fuse combinations? Answer: IEC 62271-105

MV-504 Distribution Transformer Lab 48 questions

In Dyn11, what does 11 mean? Answer: LV leads HV by 30°
LV full-load current of a 1000 kVA transformer at 400 V is... Answer: 1443 A
When may an off-circuit tap changer be operated? Answer: Only with the transformer de-energised

MV-505 Substation Design & Layout 3D 51 questions

Which items are usually found in a building distribution substation room? Answer: An RMU, one or more transformers and the LV main board
Why is a clear operating aisle needed in front of MV switchgear? Answer: So an operator can stand clear and doors or panels can open fully
A room has transformer losses of 16 kW and 2.25 m between inlet and outlet louvre centres. What inlet area does S = 0.18 P / √H give? Answer: 1.92 m²

MV-506 Short Circuit & Load Flow Studio 52 questions

What does IEC 60909 calculate? Answer: Short-circuit currents in three-phase AC systems
In IEC 60909, what replaces all the sources in the network? Answer: One equivalent voltage source c·Un/√3 at the fault point
Using Ik ≈ In / uk with an infinite source, what is the LV fault level of a 2000 kVA, 6% transformer at 400 V? Answer: 48.1 kA

MV-507 MV Protection & Relay Coordination 52 questions

What does IDMT stand for? Answer: Inverse definite minimum time
What does the TMS setting do on an IDMT relay? Answer: Moves the whole curve up or down in time
Using the IEC standard inverse curve, what is the trip time at 10 times Is with TMS = 0.1? Answer: 0.30 s

MV-508 MV Earthing & Step/Touch Lab 51 questions

What is ground potential rise (GPR)? Answer: The rise in voltage of the earth grid relative to remote earth during an earth fault
What is touch voltage? Answer: Between a hand on earthed metal and the feet, normally 1 m away
IEEE 80 tolerable touch voltage for 50 kg with no surface layer, soil ρ = 100 Ω·m and ts = 0.5 s is about... Answer: 189 V

MV-509 MV Testing & Commissioning Lab 50 questions

What does an insulation resistance test measure? Answer: The resistance of the insulation between conductor and earth or between conductors
How is the polarisation index (PI) calculated? Answer: IR at 10 minutes divided by IR at 1 minute
A 400/1 CT feeds a relay set to pick up at 1.0 A secondary. What primary current does that represent? Answer: 400 A

MV-510 Switching, Safety & Permits Simulator 47 questions

What is a switching program? Answer: A written, numbered list of every switching operation, in order, with who does it and where
What is the correct core sequence for making MV equipment safe? Answer: Isolate, prove dead, earth, lock and tag, issue permit
What are the five safety rules of EN 50110-1, in order? Answer: Disconnect, secure against reconnection, verify absence of voltage, earth and short-circuit, protect against adjacent live parts

MV-511 Utility Approvals & Interface Workflow 47 questions

Why does a utility ask for a substation on the developer's land? Answer: When the building load is too large for an LV connection from the street network
What is usually the first step in getting a new MV connection? Answer: Submitting a load application with the maximum demand estimate
Activities: A (4 weeks), then B (6 weeks) and C (3 weeks) in parallel after A, then D (5 weeks) after both. What is the project duration? Answer: 15 weeks

MV-512 Power Quality & Reactive Compensation 50 questions

What causes harmonics in a building supply? Answer: Non-linear loads such as drives, UPS rectifiers, LED drivers and IT power supplies
What does THD stand for? Answer: Total Harmonic Distortion
A load currents are I1 = 100 A, I5 = 20 A, I7 = 14 A, I11 = 9 A and I13 = 7 A. What is the current THD? Answer: 27%

MV-513 Renewables, BESS & EV MV Integration 48 questions

When does a fixed-tilt solar PV system usually produce its peak output? Answer: Around midday
What is reverse power flow at an MV connection? Answer: Power flowing from the site back into the network
Using dV% = (PR + QX)/V² x 100, what is the rise for 1.5 MW export at unity power factor on 11 kV through R = 1.2 ohm? Answer: About 1.5%

MV-514 Digital Substation, SCADA & IEC 61850 50 questions

What does a merging unit do in a digital substation? Answer: Digitises CT and VT signals and publishes them as sampled values
What is a GOOSE message used for? Answer: Fast trips, interlocks and status between IEDs
How many SV frames per second are sent at 80 samples per cycle on a 50 Hz system? Answer: 4,000

MV-515 Condition Monitoring & Failure Forensics 50 questions

What does DGA stand for in transformer maintenance? Answer: Dissolved Gas Analysis
Which gas most strongly signals arcing in transformer oil? Answer: Acetylene
A DGA result gives CH4 60, C2H4 200 and C2H2 4 ppm. Which Duval zone applies? Answer: T3

MV-516 4D Substation Project Simulator 48 questions

What sizes the transformers for a building? Answer: Maximum demand with growth and planned loading
What does N+1 transformer redundancy mean? Answer: One spare unit beyond what the load needs
A 30,000 m² hotel at 80 W/m², diversity 0.75, power factor 0.9 and 15% growth gives what design demand? Answer: 2,300 kVA

How to use the MV question bank

Start at Beginner for the modules you are new to, and move up once you score 80% or more. Practitioner questions cover the design choices and site practice you meet on real projects. Expert questions include calculations (fault levels, IDMT times, IEEE 80 touch voltages, resonance, voltage rise) and the edge cases that catch people out in reviews.

The bank is useful for graduate training, interview preparation, and refreshers before authority or utility exams in the GCC, Saudi Arabia, Australia, New Zealand and Asia. It does not copy any official exam. Questions are written from the IEC, IEEE, AS/NZS and utility practice covered in the MEPVirtual MV labs.

Download and reuse

You can download all 788 questions as CSV (opens in Excel) or JSON for an LMS or your own app. Each row has the module, level, region, four options, the correct answer, an explanation and a reference. Please credit MEPVirtual when you use them.

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Frequently asked questions

How many questions are in the MV question bank?

There are 788 multiple choice questions across the 16 MEPVirtual MV modules, about 50 per module, at Beginner, Practitioner and Expert level.

Are these real utility or licence exam questions?

No. They are original questions written to the same standards and practice those exams draw on (IEC, IEEE, AS/NZS and utility rules). They are good preparation, but always check the syllabus your authority publishes.

Is my progress saved?

Yes, in your browser on this device. Nothing is sent to a server. Use Clear progress to reset it.

Can I use the questions for my company training?

Yes. Download the CSV or JSON and credit MEPVirtual. Verify answers against your local standards and utility requirements before using them for formal assessment.

What is the pass mark in exam mode?

70%, with 72 seconds per question. You get a full review of every question after you submit.

Related MEPVirtual labs

MV-500 Medium Voltage Hub MV-503 RMU & Switchgear Lab MV-507 Protection Coordination MV-516 4D Project Simulator

Standards referenced

IEC 62271 series (MV switchgear)
IEC 60502-2 and IEC 60287 (cables)
IEC 60076 series (transformers)
IEC 60909 and IEC 60255 (fault and protection)
IEEE 80, AS 2067, ENA EG-0 (earthing)
IEEE 400.2, IEEE 519, IEC 61850, IEC 60599