Power System4

  1. To prevent maloperation of deferentially connected relay while energizing a transformer, the relay restraining coil is biased with

    Under construction.

  2. Our household apparatus are connected in

    Under construction.

  3. The insulation of modern EHV is designed based on

    Under construction.

  4. For 132 KV system, the reactance and capacitance up to the location of the CB is 3 Ω and 0.015 microfarad respectively. The maximum value of R.R.R.V is

    Under construction.

  5. The arc voltage produced in an ac circuit breaker is always

    Under construction.

  6. Which of the following circuit breakers produce least arc energy?

    Under construction.

  7. A power station supplies the peak load of 50 MW, 40 MW and 70 MW to three localities. The annual load factor is 0.50 p.u. and the diversity factor of the load at the station is 1.55 the maximum demand on the station and average load respectively will be

    Under construction.

  8. A generating station has a maximum demand of 50 MW a load factor of 60 %, a plant capacity factor of 45 % and if the plant while running as per schedule were fully loaded. The daily energy produced will be

    Under construction.

  9. When bundle conductor are used in place of single conductor the effective inductance and capacitance will respectively

    Under construction.

  10. In synchronous generator a synchronous dead load (lamp, furnaces etc) has no ____________ hence it has no natural frequency of oscillation.

    Under construction.

  11. The conductor of a 10 km long single phase, two wire line are separated by a distance of 1.5 m the diameter of each conductor the inductance of the circuit is

    Under construction.

  12. In diesel engine, gas engine type of machine contains ___________________ pole type of alternator.

    Under construction.

  13. A 100 Km long transmission line is loaded at 110 kV. If the loss of line is 5 MW and the load is 150 VA the resistance of the line is

    Under construction.

  14. The load duration curve for a system is 8 hours 30 MW, 16 hours 25 MW and 24 hours 20 MW. The load factor will be

    Under construction.

  15. For a fixed value of complex power flow in a transmission line having a sending end voltage V, the real power loss will be proportional to

    Under construction.

  16. A three phase , 33 kV oil circuit breaker is rated 1200 A, 2000 MVA, 3 s . The symmetrical breaking current is

    Symmetrical breaking current = 2000 / √3 × 33 = 35 kA.

  17. Total instantaneous power supplied by a 3 phase ac supply to a balanced RL load is

    Under construction.

  18. What are the tests performed for oil-filled and gas-filled cables ?

    Other tests include dielectric thermal resistance tests, cold power factor test, mechanical test and binding tests.

  19. What are the methods of laying underground cables?

    There is another method i.e solid system / through laying.

  20. A 3 core cable gives on test a capacitance of 3.7 microfarad between two cores. Find the line charging current of the cable when it is connected to 11 kV, 50 Hz system?

    C2 = 3.7 microfarad and capacitance between core to neutral CN = 2 × 3.7 = 7.4 microfarad . Phase voltage ( Vp ) = 11000 / √3 = 6350.85 V, line charging current = 2πfVpCN = 14.76 A.