NERC BI Exam Prep Free practice test →

Free NERC BI Practice Questions

10 free, exam-style Balancing and Interchange Operator Certification (NERC BI) practice questions with answers and explanations. No signup required. Work through them below, then take the full free NERC BI practice test to study every exam domain.

Question 1

A Balancing Authority has Net Interchange Actual of 1,025 MW, Net Interchange Scheduled of 1,000 MW, a frequency bias setting of -50 MW/0.1 Hz, actual frequency of 59.95 Hz, and scheduled frequency of 60.00 Hz. Ignoring meter error, what is the Area Control Error (ACE)?

  1. 0 MW
  2. -25 MW
  3. +25 MW
  4. +50 MW
Show answer & explanation

Correct answer: A - 0 MW

Question 2

A Balancing Authority is observing a sustained positive Area Control Error. Assuming normal operation, what does this most directly indicate the BA should do?

  1. Increase its scheduled imports from neighbors
  2. Raise the frequency bias setting toward zero
  3. Decrease generation to bring ACE toward zero
  4. Increase generation to bring ACE toward zero
Show answer & explanation

Correct answer: C - Decrease generation to bring ACE toward zero

Question 3

Following a reportable disturbance, within what timeframe does the Disturbance Control Standard require a Balancing Authority (or Reserve Sharing Group) to recover its Area Control Error?

  1. 5 minutes after the disturbance begins
  2. 10 minutes after the disturbance begins
  3. 30 minutes after the disturbance begins
  4. 15 minutes after the disturbance begins
Show answer & explanation

Correct answer: D - 15 minutes after the disturbance begins

Question 4

An interchange transaction has been submitted and has passed all required reliability assessments and approvals, but its scheduled start time has not yet arrived and it is not yet flowing. Which interchange state best describes it?

  1. Arranged Interchange, still awaiting reliability evaluation
  2. Confirmed Interchange, approved but not yet flowing
  3. Implemented Interchange, currently being acted upon
  4. Inadvertent Interchange, an unscheduled real-time deviation
Show answer & explanation

Correct answer: B - Confirmed Interchange, approved but not yet flowing

Question 5

A 120 MW interchange transaction ramps linearly from 0 to 120 MW over the 20 minutes spanning the top of the hour, then holds at 120 MW for the remainder of that clock hour. Approximately how much energy is delivered during that hour?

  1. 60 MWh
  2. 100 MWh
  3. 120 MWh
  4. 140 MWh
Show answer & explanation

Correct answer: B - 100 MWh

Question 6

A generating unit with a 5% droop characteristic is operating on a 200 MW base in a 60 Hz system. Approximately how much will its output change in response to a 0.1 Hz drop in system frequency?

  1. About 6.7 MW
  2. About 3.3 MW
  3. About 0.5 MW
  4. About 10 MW
Show answer & explanation

Correct answer: A - About 6.7 MW

Question 7

What is the primary purpose of Time Error Correction in an interconnection?

  1. To resynchronize the SCADA and EMS system clocks to GPS reference time
  2. To recalibrate the tie-line revenue meters shared between balancing areas
  3. To correct the accumulated difference between interconnection and standard time
  4. To adjust each Balancing Authority's frequency bias setting on a seasonal basis
Show answer & explanation

Correct answer: C - To correct the accumulated difference between interconnection and standard time

Question 8

A Balancing Authority has committed all available resources and now forecasts it will be unable to meet its expected energy requirements later today. It is issuing public conservation appeals and arranging emergency purchases, but has not curtailed any firm load. Which Energy Emergency Alert level applies?

  1. EEA 0, normal operations with no anticipated energy supply concern
  2. EEA 1, all available resources committed and operating conditions tight
  3. EEA 3, firm load now being curtailed in order to maintain reliability
  4. EEA 2, unable to meet expected energy without emergency measures
Show answer & explanation

Correct answer: D - EEA 2, unable to meet expected energy without emergency measures

Question 9

Contingency reserve carried by a Balancing Authority or Reserve Sharing Group is sized primarily to cover which event?

  1. The forecast error in the next-day peak load
  2. The loss of the Most Severe Single Contingency
  3. The routine minute-to-minute regulation duty
  4. The largest scheduled generator maintenance outage
Show answer & explanation

Correct answer: B - The loss of the Most Severe Single Contingency

Question 10

An operator issues a Reliability Directive over the phone. The receiver replies, "Understood, will do." Under NERC communications requirements, what must occur before the communication is considered complete?

  1. The directive must be reissued in writing and retained for the record
  2. The issuer must first obtain approval from the Reliability Coordinator
  3. The receiver must repeat it back and the issuer must confirm it is correct
  4. The directive must be logged in the operating log within one hour
Show answer & explanation

Correct answer: C - The receiver must repeat it back and the issuer must confirm it is correct

Ready for the real thing?

Practice hundreds more NERC BI questions with instant scoring, weak-area drills, and full exam simulations.

Start the free practice test See pricing