Multiple choice questions on Power Systems- 4

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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


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