Osmania University (OU) 2007 B.E Electronics & Tele-Communication Engineering osmania universtiy - Question Paper

OSMAINA UNIVERSTY
ELECTRICAL TECHNOLOGY

PART A:

1. Draw the magnetisation characteristics of DC generator. What do you mean by critical resistance?

2. Write the formula for the torque developed in DC motor.

3. Write the relationship for line and phase volumes for both star and delta connections.

4.Explain why a shunt DC motor is called a constant speed motor.


5. discuss voltage regulation of transformer.

6. If iron and copper losses at 1/2 load are 100 W and 200 W respectively, the full load iron and copper losses are - ?
7. discuss why single phase induction motors are not self starting.

8. A six pole three - phy induction motor is connected to 50 hz supply. if it is running at 770 rpm, obtain the slip.

9. provide examples of non conventional energy sources.

10. describe rgulation and efficiency of a transmission line.

PART B:

11.(a) Derive the formula for torque developed in a DC motor.
(b) A 30 kw, 300 v, dc shunt generator has armature and field resistances of 0.05 ohms and 100 ohms respetively. compute the total power developed by the armature when it delivers full load output.

12. (a) discuss power measurement by 2 wattmeter method.
(b)explain armature reaction in alternator.

13.explain the advantages and disadvantages of auto transformer.
(b) A 10 kva, 200/400v, 50 hz, 1-phi transformer has the folllowing test results: 6
OC test- 200v, 1.3 A, 120W on LV side.
SC test - 22v, 30 A, 200 W on HV side
compute (I0 magnetising and core loss component at 50 hz and rated voltage, (ii) magnetising brnch impedances, (iii) regulation at full load at 0.8 pf leading

14. discuss with neat deagram operation and construction of nuclear power plant.

15. (a) define star/delta starter of a 3-pi induction motor.
(b) discuss the operation of a split phase induction motor.

16.(a) discuss the speed control of DC motors.
(b) A six pole lap wound shunt motor has 500 conductors. The armature and shunt field resistances are 0.05 ohms and 25 ohm respectively. obtain the speed of the motor if it takes 120 A from supply of 100 V flux/pole is 20 mWb.

17. Write sort notes on :
(a) applications of 1-PHi induction motors
(b) compound motors.

Earning:   Approval pending.