ERCOT System Operator Certification EXAM
UPDATED QUESTIONS WITH CORRECT ANSWERS
SOLVED.
A resistance of 5 ohms is connected to a resistance of 10 ohms in an electric circuit.
What is the total resistance if the two resistances are connected (i) in series and (ii) in
parallel? - CORRECT ANSWER✅✅(i) 15 ohms (ii) 3.33 ohms
An induction generator can be used to supply both active and reactive power to the
system. True or false? - CORRECT ANSWER✅✅False, induction generators are
always inductive loads and always absorb MVAR.
At a certain bus, current lags voltage by 72. What fraction of a cycle does this 72 phase
lag correspond to? - CORRECT ANSWER✅✅1/5th
For many actual electrical circuits, the earth serves as the return path for the current
flow. True or false? - CORRECT ANSWER✅✅True
In December, 2009, ERCOT's electrical market was changed from a Zonal to Nodal
model. This means that: - CORRECT ANSWER✅✅Transmission system congestion is
now managed between thousands of small points (nodes) in the ERCOT system, rather
than between a few large zones.
The output of a generating unit is 500 MW. Express this value in watts. - CORRECT
ANSWER✅✅500,000,000 watts
There are electrical connections between ERCOT and the Eastern Interconnection.
True or False? - CORRECT ANSWER✅✅True, there are two DC ties connecting
ERCOT with the Eastern Interconnection. There are no closed AC ties.
What are the essential components of an electric circuit? - CORRECT
ANSWER✅✅Voltage source, load, supply path, return path
What is the peak value of the voltage amplitude for a 345 KV AC voltage? - CORRECT
ANSWER✅✅345/.707= 244 KV
What is the per-unit value of a 345 KV bus voltage, if SCADA shows the actual bus
voltage to be 358.8 KV? If operating criteria require voltage to be within 5% of the
nominal value, is the bus voltage within limits? - CORRECT ANSWER✅✅1.04, Yes
UPDATED QUESTIONS WITH CORRECT ANSWERS
SOLVED.
A resistance of 5 ohms is connected to a resistance of 10 ohms in an electric circuit.
What is the total resistance if the two resistances are connected (i) in series and (ii) in
parallel? - CORRECT ANSWER✅✅(i) 15 ohms (ii) 3.33 ohms
An induction generator can be used to supply both active and reactive power to the
system. True or false? - CORRECT ANSWER✅✅False, induction generators are
always inductive loads and always absorb MVAR.
At a certain bus, current lags voltage by 72. What fraction of a cycle does this 72 phase
lag correspond to? - CORRECT ANSWER✅✅1/5th
For many actual electrical circuits, the earth serves as the return path for the current
flow. True or false? - CORRECT ANSWER✅✅True
In December, 2009, ERCOT's electrical market was changed from a Zonal to Nodal
model. This means that: - CORRECT ANSWER✅✅Transmission system congestion is
now managed between thousands of small points (nodes) in the ERCOT system, rather
than between a few large zones.
The output of a generating unit is 500 MW. Express this value in watts. - CORRECT
ANSWER✅✅500,000,000 watts
There are electrical connections between ERCOT and the Eastern Interconnection.
True or False? - CORRECT ANSWER✅✅True, there are two DC ties connecting
ERCOT with the Eastern Interconnection. There are no closed AC ties.
What are the essential components of an electric circuit? - CORRECT
ANSWER✅✅Voltage source, load, supply path, return path
What is the peak value of the voltage amplitude for a 345 KV AC voltage? - CORRECT
ANSWER✅✅345/.707= 244 KV
What is the per-unit value of a 345 KV bus voltage, if SCADA shows the actual bus
voltage to be 358.8 KV? If operating criteria require voltage to be within 5% of the
nominal value, is the bus voltage within limits? - CORRECT ANSWER✅✅1.04, Yes
