Multiple choice questions on Power Systems- 4

By -

Important Multiple Choice Questions On Power Systems
1. With 100 % inductive shunt compensation, the voltage profile is flat for

  1. 100% loading line
  2. 50% loading line
  3. Zero loading of line
  4. None of these
2. For a long uncompensated line the limit to the line loading is governed by

  1. Thermal limit
  2. Voltage drop
  3. Stability limit
  4. Corona loss
3. Series capacitive compensation in EHV transmission lines is used to

  1. Reduce the line loading
  2. Improve  the stability of the system
  3. Reduce the voltage profile
  4. Improves the protection of the line
4. The main consideration for higher and higher operating voltage of transmission is to

  1. Increase the efficiency of transmission
  2. Reduce power losses
  3. Increase power transmission capability
  4. Both (A) and (B) above
5. The inertia constant H of a machine of 200MVA is 2 p.u. its value corresponding to 400MVA will be

  1. 4
  2. 2
  3. 1
  4. 0.5
6. A 500MVA, 11kV synchronous generator has 0.2 p.u. synchronous reactance. The p.u. synchronous reactance on the base values of 100 MVA and 22kV is

  1. 0.16
  2. 0.01
  3. 4
  4. 0.25
7. Bulk power transmission over long HVDC lines are preferred, on account of

  1. Low cost of HVDC terminals
  2. No harmonics problems
  3. Minimum line power losses
  4. Simple protection
8. The transient stability of power system can be effectively improved by

  1. Excitation control
  2. Phase shifting transformer
  3. Single pole switching of circuit breakers
  4. Increasing the turbine valve opening
9. The critical clearing time of a fault in power systems is related to

  1. Reactive power limit
  2. Short-circuit current limit
  3. Steady-state stability limit
  4. Transient stability limit
10. Steady-state stability of power systems is improved by

  1. Reducing fault clearing time
  2. Using double circuit line instead of single circuit line
  3. Single pole switching
  4. Decreasing generator inertial


Comments

Post a Comment

Popular posts from this blog

Multiple Choice Questions in Power Electronics - 1

By -
  Important multiple choice questions from Power Electronics 1.       Which one of the following statements is not correct? a)       Power MOSFETs are so constructed as to avoid punch through. b)       In a power MOSFET, the channel length is relatively large and channel width is relatively small c)       Power MOSFETs do not experience any minority carrier storage d)       Power MOSFETs can be put in parallel to handle large currents 2.       Which one is most suitable power device for high frequency (>100 kHz) switching application? a)       Power MOSFET b)       BJT c)       Schottky diode d)       Microwave transistor 3.       A thyristor equivalent of thyratron tube is a)       SCR b)       UJT c)       Diac d)       Triac 4.       Turn-on of thyristor takes place when a)       Anode to cathode voltages is positive b)       Anode to cathode voltages is negative c)       There is a positive current pulse at the gate d)       The
Read more

Multiple Choice Questions on Power System - 3

By -
Important multiple choice questions on power system 1.        A line trap in carrier current relaying tuned to carrier frequency presents A)      High impedance to carrier frequency but low impedance to power frequency B)       Low impedance to both carrier and power frequency C)       High impedance to both carrier and power frequencies D)      Low impedance to carrier frequency and high impedance to power frequency 2.        The use of fast acting relays and circuit breakers for clearing a sudden short circuit on a transmission link between generator and the receiving end bus improves the transient stability of the machine because A)      Short circuit current becomes zero B)       Post-fault transfer impedance attains a value higher than that during the fault C)       Ordinate of the post-fault power-angle characteristic is higher than that of during fault characteristic D)      Voltage behind the transient reactance increases to a higher value 3.        A
Read more