15. Power factor of a power system can be improved by
A. using phase advances, static capacitors, capacitance boosters
B. unexcited synchronous motors on load
C. over excited synchronous motors on no load
D. both A and B above
16. The function of guard ring transmission lines is
A. to reduce the transmission losses
B. to reduce the earth capacitance of the lowest unit
C. to increase the earht capacitance of the lowest unit
D. none of these
17. Use of bundle conductors causes the critical voltage for cornona formation
A. to decrease
B. to increase
C. to remain unlatered
D. does not existent
18. The surge impedance of a long power transmission line is of the order of
A.500
B.750
C. 400S-2
D. 800S2
19. Booster transformer is located at
A. sending end of transmission line
B. receiving and of transmission line
C. intermediate point on a transmission line
D. none of these
20. Surge impedance of a transmission line is given by
A. IETC
B.1/12Z
C.1/24Z
D.1 /16-Z
21. The string efficiency of an insulator can be increased by
A. reducing the number of strings in the insulator
B. increasing the number of strings in the insulator
C. correct grading of insulators of various capacities
D. none of these
Page 3 of 54