53.
Locomotive having mono-motor bogies

55.
Which of the following methods is used to control speed of 25 kV, 50 Hz single phase traction?

57.
For three-phase induction motors which of the following is the least efficient method of speed control?

58.
Which of the following is the advantage of electric braking?

59.
Speed-time curve of main line service differs from those of urban and suburban services on following account