aptransco.cgg.gov.in Electrical & Electronics Engineering Exam Question Paper : Transmission Corporation Of Andhra Pradesh

Name of the Organization : Transmission Corporation Of Andhra Pradesh Limited
Exam : Electrical & Electronics Engineering Exam
Document Type : Sample Question Paper
Year : 2016
Subject : Electrical & Electronics Engineering

Website : https://aptransco.co.in/
Download Question Paper : https://www.pdfquestion.in/uploads/11690-Electrical.pdf

Electrical & Electronics Engineering Exam Question Paper :

Duration of Test : 2 Hours
Max. Marks : 100
Instructions :
1. This Question Booklet consists of 100 multiple choice objective type questions to be answered in 2 hours.

Related : Transmission Corporation Of Andhra Pradesh Civil Engineering Exam Model Question Paper : www.pdfquestion.in/11686.html

2. Every question in this booklet has 4 choices marked (A), (B), (C) and (D) for its answer.
3. Each question carries one mark. There are no negative marks for wrong answers.
4. This Booklet consists of 16 pages. Any discrepancy or any defect is found, the same may be informed to the Invigilator for replacement of Booklet.
5. Answer all the questions on the OMR Answer Sheet using Blue/Black ball point pen only.
6. Before answering the questions on the OMR Answer Sheet, please read the instructions printed on the OMR sheet carefully.
7. OMR Answer Sheet should be handed over to the Invigilator before leaving the Examination Hall.
8. Calculators, Pagers, Mobile Phones, etc., are not allowed into the Examination Hall.
9. No part of the Booklet should be detached under any circumstances.
10. The seal of the Booklet should be opened only after signal/bell is given.

Electrical And Electronics Engineering :
Part – A :
1. The main purpose of using core in a transformer is to
(A) decrease iron losses
(B) eliminate magnetic hysteresis
(C) reduce reluctance of the common magnetic circuit
(D) prevent eddy current loss

2. A 220 V separately excited dc motor takes 20 A and the armature resistance is 1.0 O. If the armature constant KaF = 1.5 rad/sec, the speed of the motor is
(A) 1000 rpm
(B) 2000
(C) 3000 rpm
(D) 4000 rpm

3. In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 O, the external resistance is
(A) 0.2 O
(B) 0.3 O
(C) 0.4 O
(D) 0.5 O

4. When a V-V three phase transformer system is converted into a ?-? system, increase in capacity of the system is
(A) 86.6%
(B) 50%
(C) 57.7%
(D) 73.2%

5. 3kW load is supplied by an autotransformer with 0.7 transformation ratio. Conductively transferred power from primary to secondary is
(A) 2.1 kW
(B) 0.9 kW
(C) 4.29 kW
(D) 3 kW

6. Number of commutator bars for a 4-pole, 2-layer, DC lap winding with 24 slots and one conductor per layer is
(A) 48
(B) 24
(C) 192
(D) 96

7. The torque developed by any 3-phase induction motor at 0.8 p.u. slip is
(A) Full-load torque
(B) unstable torque
(C) starting torque
(D) break down

8. The Eb/V ratio of a DC motor is an indication of its ________. (Eb is the back emf and V is the applied voltage across the armature)
(A) Speed regulation
(B) Starting torque
(C) Efficiency
(D) Running torque.

9. Which of the following test is usually conducted to determine the efficiency of traction motors ?
(A) Field’s test
(B) Swinburne’s test
(C) Hopkinson’s test
(D) Retardation test.

10. An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is
(A) 5.06 kW
(B) 0.3 kW
(C) 100 kW
(D) 83.33 kW

11. A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor rotates at a speed of ________ rpm with respect to stator field.
(A) 1500
(B) 0
(C) 1440
(D) 60

12. Generally, Crawling in squirrel cage induction motors is tendency to run stably at speeds as low as
(A) One-third of their synchronous speed
(B) One-fifth of their synchronous speed
(C) One-seventh of their synchronous speed
(D) One-ninth of their synchronous speed

13. The starting torque of a capacitor-start induction-run motor is directly related to the angle ‘?’ between its two winding currents by the relation
(A) cos
(B) sin
(C) tan
(D) sin 1/2

14. The fractional-pitch used for eliminating 7th harmonic from the emf wave of an alternator is
(A) 2/3
(B) 5/6
(C) 7/8
(D) 6/7

15. A 2-pole, 50 Hz, 3-phase, 100 MVA, 33 kV turbo-alternator connected to an infinite bus has a moment if inertia of 107 kg-m2 in its rotating parts. It has a synchronous reactance of 0.5 p.u. The natural time period of oscillations of the machine is
(A) 7.874 sec
(B) 15.748 sec
(C) 23.622 sec
(D) 24.9 sec

16. While keeping the excitation constant, if the steam supply of an alternator running in parallel with another identical alternator is increased, then
(A) It would over-run the other alternator
(B) Its rotor will fall back in phase with respect to the other machine
(C) Its portion of share in load will increase
(D) Its power factor would be decreased.

17. The effect of increasing load on a synchronous motor running with normal excitation is
(A) Increase both its Ia and power factor.
(B) Decrease Ia, but increase power factor.
(C) Increase Ia, but decrease power factor
(D) Decrease both Ia and power factor.

18. Transmission lines are transposed to reduce
(A) Ferranti effect and voltage level
(B) Skin effect and efficiency
(C) Proximity effect and current density
(D) Interference with neighboring communication lines

19. If the base current and base voltage of a 345 kV system are 3000 A and 300 kV respectively, per-unit voltage and base impedance of the system respectively are
(A) 1.15 pu, 115
(B) 1.15 pu, 100
(C) 0.87 pu, 115
(D) 0.87 pu, 100

20. The surge impedance of a 60 miles long underground cable is 50 ?. For a 30 miles length it will be
(A) 25
(B) 50
(C) 100
(D) 200