Checked 27 October 2026. The standards behind the worked examples were read on nerc.com on 27 October 2026, in the versions then Mandatory Subject to Enforcement. Standards are revised and replaced; check the current version on nerc.com before you rely on a requirement number.
People search for NERC exam practice questions and sample questions. NERC’s program manual says its exam questions are its confidential property and that candidates who copy, share or post them can lose their credential. What NERC does publish is the content outline for each exam, a list of references led by the Reliability Standards, and a description of the three kinds of question it writes. This page works through two practice questions of our own, written from those standards, and sets out the standard families NERC lists.
ProSyllabus is an independent study site. It is not part of NERC (the North American Electric Reliability Corporation), and nothing here is a NERC exam or a NERC exam question. The NERC exam facts and requirement summaries on this page are drawn from the nerc.com documents listed at the foot of the page; the study advice and the product description are ours.
Exam facts: NERC Program Manual v4.2 and Exam Resource Materials (Jan 2025), read 27 Oct 2026.
FreeTests: Contingency Analysis and Reliability · Resource and Demand Balancing · Communications and Data
NERC System Operator Certification Practice Test: free sample
Answer 3 questions against the clock, like the real exam. You then see the right answer, the reason and your time on each. About 4 minutes · free · no sign-in.
3 questions to answer
Start nowabout 5 minThis one is free · no sign-in needed
Your result shows how long each question took you.
How to use the worked examples
Choose an answer before you open “Show the answer”. In our practice questions, a useful habit is to name, before you look at the options, the requirement that decides the answer: who must act, what triggers it and by when. Then check the explanation and the standard to reread.
Worked example 1: an IROL
Worked example 1 · Contingency Analysis and Reliability
At 14:10 actual flow on a flowgate rises above its IROL, whose IROL Tv is 20 minutes, and the Reliability Coordinator sees it at once. The redispatch already under way will take about 25 minutes to bring the flow back within the IROL. What must the Reliability Coordinator do?
- (A) Let the redispatch run alone and accept that relief will come at about 14:35
- (B) Wait until 14:30, then begin new actions if the flow is still high
- (C) Raise the IROL temporarily so the flow is no longer above it
- (D) Direct further actions, Load shedding if needed, so it is relieved by 14:30
Show the answer
Answer: (D) Direct further actions, Load shedding if needed, so it is relieved by 14:30. IRO-009-2 R3 requires the Reliability Coordinator to act or direct others to act so that the magnitude and duration of an IROL exceedance is mitigated within the IROL's Tv, here by 14:30 (14:10 plus 20 minutes); redispatch alone would overrun it. The actions IRO-009-2 R1 requires it to plan for go up to and including load shedding, and the NERC Glossary defines the IROL Tv as the maximum time the IROL can be violated.
Standard to reread: IRO-009-2 R3
An original ProSyllabus question written from the NERC Reliability Standards and Glossary of Terms. Not a NERC exam question.
Why it matters: the NERC Glossary defines an IROL as a System Operating Limit that, if violated, could lead to instability, uncontrolled separation or Cascading outages, and gives each IROL a Tv, the maximum time it can be violated. IROLs are a sub-area of the Contingency Analysis and Reliability domain on every outline; when you practise them, ask who must act and by when.
Worked example 2: Reporting ACE
Worked example 2 · Resource and Demand Balancing
It is 14:20. Your Balancing Authority's energy management system shows an Actual Net Interchange of 400 MW and a Scheduled Net Interchange of 500 MW. Frequency is 59.98 Hz against a Scheduled Frequency of 60.00 Hz, your Frequency Bias Setting is -50 MW/0.1 Hz, and Interchange Meter Error and Inadvertent Interchange Management are both zero. What is your Reporting ACE?
- (A) +110 MW
- (B) -110 MW
- (C) -90 MW
- (D) -100 MW
Show the answer
Answer: (B) -110 MW. The NERC Glossary gives Reporting ACE = (NIA - NIS) - 10B(FA - FS) - IME + IIM. Here (400 - 500) = -100 MW and 10 x (-50) x (59.98 - 60.00) = +10 MW, so Reporting ACE = -100 - 10 = -110 MW. Adding the bias term instead of subtracting it gives the wrong -90 MW.
Standard to reread: NERC Glossary: Reporting Area Control Error (Reporting ACE)
An original ProSyllabus question written from the NERC Reliability Standards and Glossary of Terms. Not a NERC exam question.
Why it matters: area control error is one of the Resource and Demand Balancing sub-areas on every outline, and NERC lists calculating and monitoring it among the exam tasks. When you practise it, check the sign of ACE, what each term of the equation does, and what the Balancing Authority must do after a Balancing Contingency Event.
The standard families NERC lists
The Exam Resource Materials say primary interest should go to the NERC Glossary of Terms and nine standard families. The summaries are ours; the requirements are in the standards on nerc.com.
| Family | What it covers, in short |
|---|---|
| BAL | Real power balancing: control performance and Reporting ACE (BAL-001), Contingency Reserve and recovery from a Balancing Contingency Event (BAL-002), frequency response and bias (BAL-003), Balancing Authority control (BAL-005) |
| COM | Interpersonal Communication and alternatives (COM-001); three-part communication and Operating Instructions (COM-002) |
| EOP | Event reporting (EOP-004), restoration from Blackstart Resources and its coordination (EOP-005, EOP-006), loss of control center functionality (EOP-008), geomagnetic disturbances (EOP-010), emergency operations and Energy Emergency Alerts (EOP-011), extreme cold weather (EOP-012) |
| FAC | Facility Ratings (FAC-008), vegetation management (FAC-003), SOL methodology and establishing SOLs and IROLs (FAC-011, FAC-014) |
| INT | Evaluating and implementing Interchange (INT-006, INT-009) |
| IRO | The Reliability Coordinator: responsibilities, monitoring, operational analyses and Real-time Assessments, IROL actions, data, coordination and outage coordination (IRO-001 to IRO-018) |
| PRC | Protection Systems: misoperations, underfrequency and undervoltage load shedding, Remedial Action Schemes, relay loadability, generator ride-through |
| TOP | Transmission operations: Operating Instructions, Real-time monitoring and Assessments, SOL exceedances, operations planning, data specification, monitoring capabilities (TOP-001, TOP-002, TOP-003, TOP-010) |
| VAR | Voltage and reactive control by the Transmission Operator (VAR-001) and generator voltage schedules and AVR operation (VAR-002) |
Numbers worth knowing cold
Several requirements carry a time limit or a testing frequency. The selection below is worth reviewing; each line names the requirement, and the full wording is in the standard on nerc.com. Note who must act as well as how fast: a question can swap the entity and keep the number.
| Rule | What the text says | Requirement |
|---|---|---|
| Real-time Assessment | The Transmission Operator ensures a Real-time Assessment is performed at least once every 30 minutes | TOP-001-6 R13 |
| IROL exceedance | The Reliability Coordinator acts or directs others so that the magnitude and duration of an IROL exceedance is mitigated within the IROL’s Tv | IRO-009-2 R3 |
| Recovery from a Reportable Balancing Contingency Event | Reporting ACE returned to at least its recovery value within the Contingency Event Recovery Period, which the NERC Glossary defines as beginning when resource output begins to decline within the first one-minute interval and extending for fifteen minutes (R1 sets the recovery value and its exceptions); Contingency Reserve restored to at least the Most Severe Single Contingency before the end of the Contingency Reserve Restoration Period, which does not exceed 90 minutes after that (R3, where a new event resets the clock) | BAL-002-3 R1, R3; NERC Glossary |
| Event reports | Events in EOP-004-4 Attachment 1 reported by the later of 24 hours of recognising that a threshold was met or the end of the Responsible Entity’s next business day (4 p.m. local time) | EOP-004-4 R2 |
| Backup control center | The Operating Plan for backup functionality includes a transition period between the loss of primary control center functionality and full backup functionality of no more than two hours | EOP-008-2 R1 |
| Alternative Interpersonal Communication | Reliability Coordinators, Transmission Operators and Balancing Authorities test it at least once each calendar month | COM-001-3 R9 |
| Data exchange redundancy | The Transmission Operator tests its primary Control Center data exchange capabilities specified in Requirement R20 for redundant functionality at least once every 90 calendar days, and starts action within two hours if a test fails | TOP-001-6 R21 |
Learning a number without its requirement is fragile: the exam can describe the situation without naming the standard. Learning the requirement as “who, what triggers it, by when” can help you with questions that describe the situation in other words.
FreeTests: Contingency Analysis and Reliability · Resource and Demand Balancing · Communications and Data
NERC System Operator Certification Practice Test: free sample
Answer 3 questions against the clock, like the real exam. You then see the right answer, the reason and your time on each. About 4 minutes · free · no sign-in.
3 questions to answer
Start nowabout 5 minThis one is free · no sign-in needed
Your result shows how long each question took you.
What our practice test covers, by domain
NERC’s outlines give the number of scored questions per domain for each exam. The counts below describe the ProSyllabus practice test only: our two mock exams follow the RC and BT outlines sub-area by sub-area, and the domain practice sets add more questions in each domain.
ProSyllabus practice test: 302 questions in an RC mock and a BT mock of 120 each, six domain practice sets and a 3-question free sample. Our counts.
| Fact | NERC exam | ProSyllabus mock |
|---|---|---|
| Questions | RC and BT 140 (120 scored); TO and BI 120 (100 scored) | 120 per mock (RC and BT), every question scored, plus domain practice sets |
| Time | 3 hours | 154 minutes per mock: the exam’s pace for 140 questions, applied to 120 |
| Pass mark | 92 of 120 (RC, BT); 76 of 100 (TO, BI) | Your score out of 120 and by domain; a practice score is not an exam result and does not predict one |
| The questions | Developed by NERC’s Exam Working Group; confidential | Written by ProSyllabus from the Reliability Standards and the NERC Glossary |
| Feedback | A pass/fail score report | Every answer explained, naming the standard and requirement or the Glossary definition, with a list of those to reread |
Want the full practice test?
If you want timed practice, the ProSyllabus NERC System Operator Certification practice test has a 120-question mock exam for RC and one for BT, a practice set for each of the six domains, your score by domain and the standard or Glossary definition behind every answer. Three questions are free, including the two above; the rest is paid. Our own questions, not NERC’s, and not made or endorsed by NERC. For the exams, booking, fees and cut scores, see the NERC certification exams and format guide.
FreeTests: Contingency Analysis and Reliability · Resource and Demand Balancing · Communications and Data
NERC System Operator Certification Practice Test: free sample
Answer 3 questions against the clock, like the real exam. You then see the right answer, the reason and your time on each. About 4 minutes · free · no sign-in.
3 questions to answer
Start nowabout 5 minThis one is free · no sign-in needed
Your result shows how long each question took you.
Frequently asked questions
Can I get real NERC exam questions?
No. NERC’s program manual says its exam questions are its confidential property and that copying, sharing or posting them is prohibited. Practise on questions written from the standards instead.
Are these real NERC questions?
No. They are ProSyllabus’s own questions, written from the NERC Reliability Standards and the NERC Glossary. Nothing here comes from a NERC exam.
Which standards come up most?
The content outlines allocate scored questions by domain and sub-area, not by standard. NERC’s Exam Resource Materials say primary interest should go to the Glossary and the BAL, COM, EOP, FAC, INT, IRO, PRC, TOP and VAR standards, and its content outlines give the questions per domain and sub-area for each exam.
What kinds of questions are on the exam?
Multiple-choice questions at three levels: recall (a fact or procedure), application (apply a rule to data or a situation) and analysis (judge the best course of action from several concepts).
Will passing the ProSyllabus mocks mean I pass the NERC exam?
No. A practice score is not an exam result and does not predict one. The questions are ours, not NERC’s.
More in this series
Sources
- official — NERC: System Operator Certification Program Manual, Version 4.2 (February 2025)
- official — NERC: Exam Resource Materials for NERC System Operator Certification Examinations (January 2025)
- official — NERC: Certification Examination Content Outline, Reliability Coordinator Operator (RC), effective June 1, 2023
- official — NERC: Certification Examination Content Outline, Balancing, Interchange, and Transmission Operator (BT), effective June 1, 2023
- official — NERC: Certification Examination Content Outline, Transmission Operator (TO), effective June 1, 2023
- official — NERC: Certification Examination Content Outline, Balancing and Interchange Operator (BI), effective June 1, 2023
- official — NERC: Reliability Standards (by family)
- official — NERC: Glossary of Terms Used in NERC Reliability Standards
official = a document published by the conducting body. reported = a news or coaching site we could not check against an original. Where sources disagree this page says so rather than picking one.
