<p>www.andhracolleges.com
Seminar Topics - Scholarships - Admission/Entrance Exam Notifications
USA-UK-Australia-Germany-France-NewZealand Universities List
Engineering-MBA-MCA-Medical-Pharmacy-B.Ed-Law Colleges Information
www.andhracolleges.com The Complete Information About Colleges in Andhra Pradesh
www.andhracolleges.com
www.andhracolleges.com
Code No: RR320206
Set No. 1
III B.Tech II Semester Regular Examinations, Apr/May 2007
UTILISATION OF ELECTRICAL ENERGY
(Electrical & Electronic Engineering)
Time: 3 hours
Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1.
(a) Compare and contrast the slip ring and squirrel cage induction motors from
the application point of view.
[6]
(b) A series motor working on 500 V d.c supply runs at a speed of 1000 r.p.m.
When The load current is 120 amps. The resistance of the motor 0.15 Ohm,
of which 0.04 Ohm is the resistance of the field. Calculate the speed of the
motor when the torque is half of the full load torque and the field winding
is connected in parallel with a diverter of resistance 0.08 Ohm, assuming an
unsaturated magnetic circuit.
[10]
2.
(a) Discuss the various losses that occur in insulating materials and how they can
be reduced.
[6]
(b) A motor has the following load cycle:
Accelerating period 0 -15 sec Load rising uniformly from 0 to 1000 h.p
Full speed period 15-85 sec Load constant at 600 h.p.
Decelerating period 85-100 sec H.p. returned to line falls uniformly from 200
to zero Decking period 100-120 sec Motor is stationary.
Estimate the size of the motor.
[10]
3.
(a) Compare high frequency and power frequency coreless furnaces.
[8]
(b) With a neat sketch explain the construction and operation of coreless furnace.
[8]
4.
(a) What are the various types of motors used for electric traction?
[8]
(b) What a the criteria followed for selection of motors for electric drive?
[8]
5.
(a) State the laws of Illumination.
[6]
(b) Explain the laws with the help of suitable diagrams, and derive an equation
of the same.
[10]
6.
(a) What