## electrical

### Transmission and Distribution MCQ Objective Questions and Answers Page - 8

1.
 High voltage dc transmission requires filters for A Current harmonics on ac side and voltage harmonics on dc side. B Voltage harmonics on ac side and Current harmonics on dc side. C Voltage harmonics on both ac and dc sides. D Current harmonics on both ac and dc sides. Answer : B Explanation :
2.
 In a 3-phase bridge rectifier circuit for  HVDC  transmission, the ratio of output dc voltage to input ac voltage is A 0.5 B 1.0 C $\sqrt{3}$ D 2 Answer : D Explanation :
3.
 In HVDC converter station equipment using thyristors it is necessary to use a large number of thyristors in series because A Current ratings of thyristors are low. B Voltage ratings of thyristors are low. C Thyristors always fail to an internal open circuit. D None of the above. Answer : B Explanation :
4.
 In the HVDC  system, the ac harmonics which gets effectively eliminated with 12 pulse bridge converters, are A Triplen harmonics B Triplen and 5th harmonics C Triplen, 5th and 7th harmonics D 5th and 7th harmonics Answer : D Explanation :