balanced 3-phase system consists of
A Zero sequence currents only.
B positive sequence currents only.
C negative and zero-sequence currents.
D zero, negative and positive sequence currents.
7. A 50 Hz four pole turbo-generator rated 100 MVA, 11 kV has an inertia constant of 8 MJ/MVA. If the mechanical input is suddenly raised to 80 MW for an electrical load of
SOM W, then the rotor acceleration is
A. 337.5 elec. degree/S?
B. 3.375 elec. degree/S?
C. 457.5 elec. degree/S?
D 4.57 elec. degree/S* 8. Which type of fault occurs when a conductor breaks, resulting in an interruption in the
current flow?
A. Are fault
B. Open circuit fault
C. Ground fault
D. Overcurrent fault
9. What is the purpose of fault classification in fault analysis?
A. To identify the location of the fault
B. To determine the cause of the fault
C. To predict the occurrence of future faults
D. To analyse the severity of the fault
10. Which fault analysis method is commonly used to study balanced three-phase faults?
A. The impedance method
B. The symmetrical component method
C. The per-unit method
D. The transient stability method 11 In a 3-phase, 4-wire system, the current in red, yellow and blue lines under abnormal
conditions of loading are as follows;
原=100L30°A；E=50L300°A；=302180°A Calculate the positive, negative and zero sequence currents in the red line and the returr
current in the neutral wire.
[10 Marks