## Tuesday, 4 August 2015

### Power Systems 2 Important Questions For External Exams

Power Systems 2 Important Questions For External Exams

Model Question I
Model Question Paper-I

Part A

1. Name the three parts of a distribution system.
2. What are the different types of bus bar arrangements?
3. Name the three types of electric drives.
4. Draw the torque load characteristic of a DC series motor.
5. Name the various traction system.
6. Define average speed and schedule speed.
7. What is meant by transition in series – parallel connections?
8. Define the following terms and state their units
i)Luminous flux ii)Luminous intensity.
9. Mention any three applications of Dielectric heating.
10. List the types of electric welding.

Part B

11. Classify the substations on the basis of service and design.
12. Compare group drive and individual drive.
13. Name the various system of track electrification.
14. State the two laws of illumination.
15. Compare are welding and resistance welding.(Only five points)

Part C

16. (a) Compare the cost of conductor in AC 3 phase 3 wire to DC 2 wire on general assumption.
(or)
(b) Draw a simple line diagram layout of a typical 11kv/400v substation with all details.

17. (a) Explain the various factors governing the selection of motors for a particular drive.
(or)
(b) Explain how plugging is applied to DC shunt motor, DC series motor and induction motors.

18. (a) A train runs with an average speed of 40kmph. Distance between stations is 2km. Values of acceleration and retandation are 1.5kmphps and 2.5kmphps respectively.Find the maximum speed of train assuming trapezoidal speed – time curve.
(or)
(b) Write short notes on (i)Bow collector (ii)Pantograph.

19. (a) Explain the shunt transition method in steps with a neat diagram.
(or)
(b) Explain with neat sketch the construction and working of a Sodium Vapour Lamp.

20. (a) Explain the principle of operation of eddy current heating with the help of neat sketch and state its applications.
(or)
(b) With a neat sketch and explain laser beam welding. Give its applications

Model Question Paper-II

Part A

1. Name the distribution system based on construction.
2. Name any three types of substations based on service requirement.
3. What are the disadvantages of individual drive?
4. Mention the types of motor used for (i)Belt conveyor (ii)Crane and (iii)Centrifugal pump.
5. Mention any two system of Railway Electrification.
6. Define tractive effort of a motor.
7. Name the three types of breaking.
8. What is an Indirect lighting?
9. What are the commonly used heating element materials?
10. What are the uses of Ajax Wyatt core type induction furnace in industries?

Part B

11. Explain Ring main system of distribution.
12. Mention any five merits in using electric breaking
13. Briefly explain about single phase low frequency system.
14. What is stroboscopic effect on Fluorescent Lamp and how it can be minimized?
15. What are the requirements of heating element material?

Part C

16. (a) A single phase AC distributor AB 200m long is fed from end ‘A’ and is loaded as under
(i)100A at 0.707p.f lagging 100m from point A
(ii)200A at 0.8p.f lagging 200m from point A
The total resistance and reactance of the distributor is 0.2ohm and 0.1ohm per kilometer. Find the total voltage drop in distributor.
(or)
(b) Name and explain the important equipments used in substation.
17. (a) Explain how dynamic breaking is applied to (i)DC shunt motor and
(ii)Induction motor with suitable circuit diagrams.
(or)
(b) Choose with reasons the suitable electric motor for (i)Cement mill (ii)Textile mill and (iii)Punching machines.

18. (a) Explain the working of a single phase 25kv composite system and state the advantages over DC systems.
(or)
(b) Describe the suitability of a DC series motor for traction duty.

19. (a) Explain the series parallel control of speed of traction motor with circuit diagram.
(or)
(b) A lamp having a uniform luminous intensity of 250CP suspended 6m above street level. What will be the illumination on the ground i) vertically below the lamp ii) 6m away from it.
20. (a) Explain with a neat sketch the construction and working of an indirect core less induction furnace.
(or)
(b) Explain the working of a high frequency dielectric heating. What are its merits and applications?