বাংলাদেশ পল্লী বিদ্যুতায়ন বোর্ড: সহকারী প্রকৌশলী পদের বিগত বছরের প্রশ্ন-২০১৪

 BANGLADESH RURAL ELECTRIFICATION BOARD

বাংলাদেশ পল্লী বিদ্যুতায়ন বোর্ড

পদের নামঃ সহকারী প্রকৌশলী (Post: Assistant Engineer (Electrical)

সালঃ ২০১৪ Full marks: 80

1. Reciprocity theorem is applicable for:

(a) Unilateral network

(b) Bilateral network

(c) Ideal network

(d) None of the these

(b) Bilateral network

2. A JFET is also called:

(a) Uni-polar transistor

(b) Bipolar transistor

(c) Uni-junction transistor

(d) None of the these

(a) Uni-polar transistor

3. Form Factor of sinusoidal alternating current is:

(a) 1.11%

(b) 1.11A

(c) 1.11

(d) b and c

(c) 1.11

4. Relation between resonant power Po and off-resonant power P is:

(a) Po=P 

(b) Po>P 

(c) Po<P

(d) None of the these

(a) Po=P

5. In a parallel resonance ac circuit following points to be remembered:

(a) The admittance equals conductance

(b) Both a and c

(c) The power factor of the circuit is unity

(d) None of the above

(b) Both a and c

6. A network which attenuates a single band of frequencies and allows those on either side to pass thorough is called:

(a) Low-pass filter

(b) High-pass fiber

(c) Band-stop filter

(d) Band-pass filler

(c) Band-stop filter

7. The frequency corresponding to half-power point on the response curve of a filter is known as:

(a) cutoff

(b) upper

(c) lower

(d) roll-off

(a) cutoff

8. If D is the electric flux density, then value of electric intensity of a medium is:

(a) D/Eo

(b) D/EoEr

(c) EoEr/D

(d) Eo/D

(b) D/EoEr

9. The stabilization of operating point in potential divider method is provided by:

(a) RE consideration

(b) Rc consideration

(c) Vcc consideration

(d) None of the these

(a) RE consideration

10. In a differential amplifier, the CMMR is limited mostly by the:

(a) CMMR of the op amp

(b) Gain-Bandwidth product

(c) Supply voltage

(d) Tolerance of the resistors

(d) Tolerance of the resistors

11. Emitter follower is used for:

(a) Current gain

(b) impedance matching

(c) Voltage gain

(d) None of the these

(b) impedance matching

12. An oscillator differs from an amplifier because it:

(a) Has more gain

(b) Requires no input signal

(c) Requires no dc supply

(d) Always has the same input

(b) Requires no input signal

13. The dimensions of L/CR are that of:

(a) Farad,

(b) Henry

(e) Ohm

(d) None of the these

14. In the breakdown region, a Zener diode behaves like a:

(a) Constant current source

(b) Constant resistance

(c) Forward biased

(d) Constant voltage source

15. The maximum efficiency of a half-wave diode rectifier is:

(a) 50%

(b) 25%

(c) 40.6%

(d) 81.2%

16. The collector of a transistor is:

(a) Heavily doped.

(b) Moderately doped

(c) Lightly doped

(d) None of the these

17. Transistor biasing is done to keep:

(a) Proper ac current in the circuit

(b) The base current small in the circuit

(c) Proper dc current in the circuit

(d) Collector current small in the circuit

18. According to Faraday's Laws of Electromagnetic Induction, an emf is induced in a conductor whenever it

(a) Lies in a magnetic field

(b) Cuts magnetic flux

(c) Moves parallel to the direction of the magnetic field

(d) Lies perpendicular to the magnetic flux

19. The phase difference between the output and input voltages of a CE amplifier is:

(a) 0°

(b) 90°

(c) 180°

(d) 270°

20. If a three-stage amplifier has individual stage gains of 10 dB 5 dB and 15 dB, then the total gain in dB is:

(a) 750 dB

(b) 30 dB

(c) 25 dB

(d) 7.5 dB

21. A push-pull circuit must use in:

(a) Class A operation

(b) Class C operation

c) Class B operation

(d) Class AB operation

22. When transistor is used an amplifier, it is operated in the:

(a) Cut off region

(b) Saturation region

(c) Active region

(d) Both a and b

23. For a given line voltage, four heating coils will produce maximum heat when connected in......

(a) All in parallel 

(b) Two parallel pairs in series

(c) All in series

(d) One pair in parallel with other two in series

24. An SCR is turned off when:

(a) Anode current is reduce to zero

(b) Gate is reverse biased

(c) Gate voltage is reduced to zero

d) All of the these

25. A MOSFET is operated with:

(a) Negative gate voltage only

(b) Positive gate voltage only

(c) Positive as well as negative gate voltage

(d) None of the these

26. Negative feedback is employed in:

(a) Oscillators

(b) Rectifiers

(c) Amplifiers

(d) None of the these

27. In a LC oscillator, the frequency of oscillation is:

(a) Proportional to LC

(b) Proportional to square root of LC

(c) inversely proportional to the square root of LC

(d) Independent of the value of LC

28. If dc supply of 10V is fed to a differentiating circuit, then output will be:

(a) 20 V

(b) 10 V

(c) 0 V

(d) a or b

29. The best way to minimize the eddy current in an armature:

(a) Commutation

(b) Lamination

(c) Lap winding

(d) All of the these

30. In TV transmission the voice signal is:

(a) AM modulated

(b) FM modulated

(c) PM modulated

(d) FSK modulated

31. When the modulating signal controls the frequency of the carrier we get:

(a) Phase modulation

(b) Amplitude modulation

(c) Frequency modulation

(d) Digital modulation

32. An ideal regulated power supply is one which has voltage regulation of

(a) 0%

(b) 1.5%

(c) 5%

(d) 10%

33. If length of the cable of transmission line is doubled, its capacitance is

(a) Doubled

(b) Halved

(c) Quadrupled

(d) None of the these

34. If a power supply has no-load and full-load voltages of 30V and 25 V respectively, then the percentage voltage regulation is:

(a) 10%

(b) 15%

(c) 20%

(d) 25%

35. An unbalanced system of 3-phase voltages having RYB sequence actually consists of

(a) A positive sequence component

(b) A zero sequence component

(c) A negative sequence component

(d) All of the above

36. Zener diode can be used as:

(a) Dc voltage regulator only

(b) Ac voltage regulator only

(c) Both ac and dc voltage regulator

(d) None of the above

37. If supply frequency is increased then skin effect is:

(a) Increase

(b) Decrease

(c) No change

(d) None of the these

38. Voltage control method of ac power system is:

(a) By excitation control

(b) Auto transformer tap changing

(c) By synchronous condenser

(d) All of the these

39. Most accurate device for measuring voltage is:

(a) Voltmeter

(b) Multi-meter

(c) CRO

(d) Both a and b

40. Primary winding of CT is connected:

(a) in series with the load

(b) In parallel with the load

(c) Between line and neutral

(d) Both a and b

41. A galvanometer in series with high resistance is called

(a) An ammeter

(b) A voltmeter

(c) An watt-meter

(d) None of the these

42. Calibration voltage for an oscillator is:

(a) 2V Peak to peak

(b) 2 V RMS voltage

(c) 2 V average voltage

(c) 2 V sinusoidal voltage

43. The universal gate is:

(a) AND gate

(b) OR gate

(c) NAND gate

(d) NOR gate

44. The speed of dc motor can be controlled by varying:

(a) Its flux per pole

(b) Resistance of armature circuit

(c) Applied voltage

(d) All of the these

45. The most likely causes of sparking at the brushes in a dc machine is/are:

(a) Open coil in the armature

(b) Defective inter-poles

(c) Incorrect brush spring pressure

(d) All of the these

46. Which of the following machines may be used as power factor correction?

(a) Induction motor

(b) Synchronous motor

(c) Alternator

(d) All of the these

47. If residual magnetism of a shunt generator is destroyed accidentally, it may be restored by connecting its shunt field:

(a) To earth

(b) To an ac source

(c) In reverse

(d) To a dc source

48. An integrating circuit is a simple RC series circuit with output taken across:

(a) R

(b) C

(c) Both R and C

(d) Any of R and C

49. Which of the following quantity maintain the same direction whether a dc machine runs as a generator or as  a motor?

(a) induced emf

(b) Armature current

(c) Field current

(d) Supply current

50. The sole purpose of commutator in a dc Generator is to:

(a) Increase output voltage

(b) Reduce sparking at brushes

(c) Provide smoother output

(d) Convert the induced ac into dc

51. The power factor of an alternator is determined by its:

(a) Speed

(c) Excitation

(b) Load

(d) Prime mover

52. A transformer transforms:

(a) Frequency

(c) Current

(b) Voltage

d) Voltage and current

53. When speed of an alternator is changed from 3600 rpm to 1800 rpm the generated emf/phase will become:

(a) One-half

(b) Twice

(c) Four times

(d) One-fourth

54. A dc motor fails to start when switched on due to following causes:

(a) Low terminal voltage

(c) Excessive friction

(b) Overload

(d) All of the these

55. The direction of force on a current carrying conductor placed in a magnetic field may be found by Fleming's Right hand rule.

(a) True

(b) False

(c) None of these

56. If the spacing between the conductors of transmission line is increased the corona effect is also increased.

(a) True

(b) False

57. Excessive sparking at the brushes is one of the indications 58. A distribution transformer links the primary and secondary of overloading of a generator.

(a) True

(b) False

58. A distribution transformer links the primary and secondary distribution system.

(a) False

(b) True

59. A Squirrel cage induction motor runs at a constant speed only so long as:

(a) Its supply voltage remains constant

(b) Its torque exactly equals the mechanical load

(c) Stator flux remains constant

(d) Torque develop by it remains constant

60. The direction of rotation of a single-phase induction motor can be reversed by:

(a) Reversing connections of both windings

(b) Reversing connections of starting winding

(c) Using a reversing switch

(d) Reversing supply connections

61. There is no transient in a pure resistive circuit.

(a) False

(b) True

(c) None of these

62. Over modulation occurs when signal amplitude greater than the carrier amplitude.

(a) True

(b) False

63. In a three phase induction motor, the relative speed of stator flux and rotor flux is called slip.

(a) False

(b) True

64. Speed of dc motor is directly proportional the flux Q and

inversely proportional to the back emf Eb.

(a) True

(b) False

65. The correct antonym of the word 'benign' is..........

(a) malignant

(b) peaceful

(c) blessed

(d) ten fold

66. Choose the correct one ---

(a) maintainance

(c) burocracy

(b) bureucracy

(d) bureaucracy

৬৭. শুদ্ধ বানান কোনটি?

ক) মূমুর্ষু

গ) মুমূর্ষ

খ) মূমুর্ষ

ঘ) মুমূর্ষু

৬৮. 'সকালে উঠিয়া আমি মনে মনে বলি' - রচয়িতা কে?

ক) কৃষ্ণচন্দ্র মজুমদার

খ) যতীন্দ্রমোহন বাগচী

গ) কুসুমকুমারী দাস

ঘ) রবীন্দ্রনাথ ঠাকুর

৬৯. রেনেসাঁ হলো -

ক) একটি ভাস্কর্যের নাম

খ) কোনটিই নয়

গ) একজন শিল্পীর নাম

ঘ) শিল্প আন্দোলনের নাম

৭০. এক নটিক্যাল মাইলে কত কিঃমিঃ?

ক) ১.৮৫২

খ) ১.৬০৬

গ) ১.৯৬৩

ঘ) ১.৭৮৬

৭১. বিশ্বের ক্ষুদ্রতম রাজধানী কোনটি?

ক) মোনাকো

খ) কোনটিই নয়

গ) ভ্যাটিকান সিটি

ঘ) মানামা

৭২. তানসেন এর অপর নাম কি?

ক) রামতনু পান্ডে

খ) হরিদাশ স্বামী

গ) বিষ্ণু গোবিন্দ যোগ

ঘ) জীবনানন্দ

৭৩. হকির যাদুকর কাকে বলা হয়?

ক) ভাস্কর পিল্লাই

খ) ধ্যানচাঁদ

গ) শাহবাজ আহমেদ

ঘ) মিলখা সিং

৭৪. হায়ারোগ্লিফিক হলো -

ক) একটি মুর্তির নাম

খ) একটি দেশের নাম

গ) একটি জাতির নাম

ঘ) একটি লিখন পদ্ধতির নাম

৭৫. নবায়নযোগ্য জ্বালানী কোনটি?

ক) কয়লা

খ) পরমানু শক্তি

গ) প্রাকৃতিক গ্যাস

ঘ) পেট্টোল

৭৬. ষ্টিফেন হকিন্স বিশ্বের একজন বিখ্যাত -

ক) পদার্থবিদ

খ) কবি

গ) রসায়নবিদ

ঘ) দার্শনিক

৭৭. ‘বাংলাদেশ স্কয়ার' কোন দেশে অবস্থিত?

ক) সিয়েরালিওন

খ) কানাডা

গ) লাইবেরিয়া

ঘ) কঙ্গো

৭৮. ময়নামতির পূর্ব নাম কি ছিল?

ক) নদীয়া

খ) হরিকেল

গ) ত্রিপুরা

জ) রোহিতগিরি

৭৯. সিডর এর অর্থ -

ক) ঘূর্ণিঝড়

খ) কান

গ) চক্ষু

ঘ) কোনটিই নয়

৮০. বিশ্বের সর্বাধিক ভাষার দেশ কোনটি

ক) যুক্তরাষ্ট্র

খ) ভারত

গ) চীন

ঘ) পাপুয়া নিউগিনি