1)(a) Determine speed controls of various system of motors which is utilized in the electric train?
(b) Explain co-efficient of adhesion and describe factors on which it depends.
2)(a) Describe different arrangement of current collection which is utilized in the electric traction.
(b) Describe current trends in electric traction in detail.
3) Two stations X and Y are 12Km apart and average speed of train is 60Kmph. Acceleration is 5Kmph, retardation in coasting is 0.3kmph and braking is 5Kmph respectively. Let quadrilateral approximation of speed, time curve, find out the duration of acceleration, coasting and braking periods and distance covered in these span of time.
4) Write down the principle of regenerative braking. Describe regenerative braking regarding:
a) DC motors,
b) Induction motors.
5)(a)What are different methods of speed control of series motors and describe their scope of speed range.
(b) Describe advantage and disadvantage of the induction motor for the traction duties?
6)(a) Write down the merits of series parallel control of motors over the rheostatic method of starting and speed control?
(b) What do you mean by multiple unit control and for what application you will propose this?