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048/21

Total Number of Questions : 32

Time : 3.00 Hours Max. Marks : 200
1. Derive the torque-current characteristic of a DC series motor. (2 Marks)
2. How accuracy and precision are different ? (2 Marks)
3. Whatare the advantages, if a free wheeling diode is connected ina single phase half wave controlled
converter ? (2 Marks)
4, Compare various compensating networks used in control system. (2 Marks)
5. Explain the importance of surge impedance compensation. (2 Marks)
6. Obtain Poisson's equation and Laplace equation from Gauss’s Law. (4 Marks)

7. The corona loss on a particular system at 50 Hz is 1 kW/phase per kilometer. What will be the
corona loss on the same system if the supply frequency is reduced by 50% ? (4 Marks)

8. Agenerating station has a maximum demand of 20 mW, load factor of 70%, a plant capacity factor

of 50% and a plant use factor of 82%. Calculate the reserve capacity of the plant, if the plant runs
as per the schedule and on full load. (4 Marks)

9. What are the advantages, if a free wheeling diode is connected across the R-L load of half wave
controlled rectifier ? (4 Marks)

10. A 66 kV system has four disc string insulator with shunt capacitance to self capacitance ratio of
0.1. Calculate string efficiency. (4 Marks)
11. Find out the percentage error of the valtmeter reading in the following circuit. (5 Marks)

20kQ
¢
50V
(~ Foe 10 20೧
100102

12. What happens if the secondary open circuited in the case of current transformers used for measuring
purposes ? (5 Marks)
13. Why the rotation direction of a shaded pole motor cannot be reversed ? (5 Marks)
| 14. Describe the function of Snubber circuit in power electronics. (5 Marks)

P.T.O.