Epri Practice test| 120 QUESTIONS| WITH COMPLETE SOLUTIONS

If a generator is producing 500 MW and 200 Mvar, is the generator? A. Leading B. Lagging C. Underexcited D. Dropping correct answer: B. Lagging What is the IEEE device number for a differential relay? A. 87 B. 86 C. 67 D. 50 correct answer: A. 87 Can a synchronous machine have a negative torque angle? What does this mean? A. Yes / the machine is absorbing reactive power B. No / the machine is absorbing active power C. No / the machine is absorbing reactive power D. Yes / the machine is absorbing active power correct answer: D. Yes / the machine is absorbing active power A customer load is fed at 120 volts. The customer voltage is doubled while the load magnitude stays the same. What effect does this have on the power losses? A. Doubles the losses B. Halves the losses C. Increases the losses by a factor of four D. Decreases the losses by a factor of four correct answer: D. Decreases the losses by a factor of four In a DC circuit, a 100 volt battery is connected to both sides of a 2 ohm resistor. What is the current through the resistor and the power usage of the resistor? A. 50 amps / 5000 watts B. 40 amps / 80 watts C. 50 amps / 100 watts D. 40 amps / 3200 watts correct answer: A. 50 amps / 5000 watts The actual voltage is 362 kV on a 345 kV bus. What is the p.u. voltage? A. 1.0 B. 1.05 C. 1.5 D. .95 correct answer: B. 1.05