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**UPPSC Polytechnic Lecturer Exam Preparation Electrical Engineering Most Expected Questions. **The UPPSC Polytechnic Lecturer Exam is to be conducted on 22nd December 2021. UPPSC Polytechnic Lecturer Exam 20 is conducted to recruit lecturers for Government polytechnic Colleges in UP for Technical Subjects. Hence the majority of questions in the exam are from respective technical domains but there are a few questions from GENERAL HINDI and GENERAL KNOWLEDGE part also to check one’s general communication skills understanding of the society. Generally, Aspirants don’t find any difficulty in the preparation of the technical part of the examination. So, for the help of aspirants, we are providing the Most Expected Questions with solutions of Electrical Engineering for UPPSC Polytechnic Lecturer Recruitment 2021. This is exclusively provided by ADDA247 to all the UPPSC Technical Lecturer Recruitment 2021 for FREE!!

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## UPPSC Polytechnical Lecturer Electrical Engineering Most Expected Questions

UPPSC LECTURER ELECTRICAL

100 MOST EXPEXTED MCQS

Q1. A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100

km, the characteristic impedance is:

(a) 4000 Ω

(b) 400 Ω

(c) 40 Ω

(d) 4 Ω

Q2. The magnitude of the open-circuit and short circuit input impedance of a

transmission line are 100 ohm and 25 ohms respectively. The characteristic impedance

of line is:

(a) 25 ohms

(b) 50 ohms

(c) 75 ohms

(d) 100 ohms

Q3. For a JFET, the typical values of amplification factor and transconductance are 80

and 200μs. Calculate the dynamic drain resistance.

(a) 500 KΩ

(b) 600 KΩ

(c) 200 KΩ

(d) 400 KΩ

Q4. A slip test is conducted on synchronous generator to determine:

(a) Slip

(b) Direct and quadrature axis reactance

(c) Sub-transient reactance

(d) Positive and negative sequence reactance

Q5. Which of the following insulators is selected for HV application?

(a) Suspension type

(b) Strain type

(c) Disc type

(d) Pin type

Q6. In the salient pole of 3-phase synchronous machine the rotor will have

(a) Larger diameter, shorter axial length

(b) Smaller diameter, larger axial length

(c) Larger diameter, larger axial length

(d) Smaller diameter, shorter axial length

Q7. An amplifier has gain without feedback as 100. To make it oscillate, feedback path

gain β must be

(a) 0.02

(b) 0.01

(c) 0.05

(d) 0.1

Q8. If a generator of 250 MVA has an inertia constant of 6 MJ/MVA, its inertia constant

on a 100 MVA base is:

(a) 2.4 MJ/MVA

(b) 10.5 MJ/MVA

(c) 6 MJ/MVA

(d) 15 MJ/MVA

Q9. The Laplace transformation of is given by

As , the value of tends to….

(a) 0

(b) 4

(c) ꝏ

(d) 1/4

Q10. Transistor is operated in its ___________ region when it works as an amplifier.

(a) Cut-off

(b) Saturation

(c) Active

(d) All of the above

Q11. When short -circuit test on a transformer is performed at 25V, 50 Hz, the drawn

current is at a lagging p.f. angle of . If test is performed at 25 V, 25 Hz and drawn

current is at a lagging p.f. angle of , then

(a)

(b)

(c)

(d)

Q12. A common collector amplifier has.

(a) High voltage gains but low current gain

(b) Low voltage gains low current gain

(c) High output impedance but low input impedance

(d) low output impedance but high input impedance

Q13. Which of the following ABCD parameters is unit less?

(a) A and D

(b) A and B

(c) B and C

(d) B and D

Q14. Condition of symmetry in Z-parameter representation is

(a) Z 11 = Z 12

(b) Z 11 = Z 22

(c) Z 12 = Z 21

(d) Z 12 = Z 22

Q15. Condition of symmetry in ABCD parameter representation is

(a) AD – BC = 1

(b) A = D

(c) C = D

(d) B = D

Q16. What is a square wave generator?

(a) Flip-flop

(b) Bi-stable multivibrator

(c) Astable multivibrator

(d) Monostable multivibrator

Q17. What is the duty cycle of the output of an astable multivibrator?

(a) 50%

(b) 100%

(c) 75%

(d) 55%

Q18. If the reflection coefficient on a line is 0.2 ∠45°. The SWR is

(a) 0.8

(b) 1.1

(c) 1.2

(d) 1.5

Q19. A monostable multivibrator has

(a) Two stable states

(b) One stable state

(c) No stable state

(d) Two quasi-stable state

Q20. The purpose of guard ring in transmission lines is to…………

(a) Reduce the reactance of the line

(b) Increase the earth capacitance of the lowest unit

(c) Reduce the transmission line losses

(d) Reduce the earth capacitance of the lowest unit

Q21. Which of the following matrix is used for load flow studies?

(a) Y bus matrix

(b) Z bus matrix

(c) Unit matrix

(d) Null matrix

Q22. Which of the following matrix is used for fault analysis?

(a) Y bus matrix

(b) Z bus matrix

(c) Unit matrix

(d) Null matrix

Q23. For load flow studies, what are the quantities specified at load bus are

(a) P and V

(b) P and Q

(c) V and δ

(d) δ and Q

Q24. For load flow studies, what are the quantities specified at generator bus are

(a) P and V

(b) P and Q

(c) V and δ

(d) δ and Q

Q25. A 40 KVA transformer has a core loss of 400 W and full-load copper loss of 800 W.

The fraction of rated load at maximum efficiency is

(a) 50 %

(b) 62.3 %

(c) 70.7 %

(d) 100 %

Q26. If the conductor radius increases, inductance of the line-

(a) increases

(b) decreases

(c) remains same

(d) may increase or decrease

Q27. Surge impedance loading of a line is proportional to

(a)

(b)

(c)

(d)

Q28. An overhead transmission line is provided with earth wire for protection against

(a) Lightning surge

(b) Switching surge

(c) Power frequency overvoltage

(d) None of the above

Q29. A lightning arrester provides

(a) Low resistance path

(b) Low impedance path

(c) High impedance path

(d) None of the above

Q30. A device having characteristics very close to that of an ideal voltage source is

(a) Vacuum diode

(b) Transistor

(c) FET

(d) Zener diode

Q31. For a feedback control system of type-2, the steady state error for a ramp input

is….

(a) Constant

(b) Zero

(c) Infinity

(d) Indeterminate

Q32. If is the amplitude of the message signal and Ac is the amplitude of the carrier

Signal, then modulation index is:

(a)

(b)

(c)

(d)

Q33. The term artificial aging in instrument is associated with

(a) Springs

(b) Damping

(c) Permanent magnet

(d) Control torque

Q34. Relative permittivity can be measured by …… bridge.

(a) Wheatstone

(b) Hay’s

(c) De-Sauty

(d) Schering

Q35. Which of the following motors is most widely used for printers?

(a) DC series motor

(b) Stepper motor

(c) Synchronous motor

(d) Induction motor

Q36. When used as a voltage regulator, a Zener diode is normally

(a) Not biased

(b) Forward biased

(c) Reverse biased

(d) None of the above

Q37. What are the average and RMS values of half wave rectified output if peak voltage

is 5 V?

(a) 1.59 V, 2.5 V

(b) 1.59 V, 5 V

(c) 3.18 V, 2.5 V

(d) 3.18 V, 5 V

Q38. What type of temperature coefficient do thermistors have?

(a) Positive

(b) Negative

(c) Either positive or negative

(d) None of these

Q39. The no-load ratio of a 50 Hz single phase transformer is 6000/250 V. The

maximum

flux in the core is 0.06 Wb. What is the number of primary turns?

(a) 450

(b) 900

(c) 350

(d) 210

Q40. A MOSFET has………terminals.

(a) two

(b) five

(c) four

(d) three

Q41. FET is advantageous in comparison with BJT because of

(a) high input impedance

(b) high gain-bandwidth product

(c) its current controlled behaviour

(d) high noise immunity

Q42. The transconductance of an FET in the saturation region equals

(a)

(b)

(c)

(d) None of the above

Q43. The form factor is equal to

(a)

(b)

(c)

(d) None of these

Q44. An analog voltage in the range -4V to 4V is converted to 3-bit digital output. The

maximum quantization error (in V) is

(a) 0.20

(b) 0.50

(c) 1.00

(d) 0.25

Q45. A network that has either voltage or current sources is called

(a) Active network

(b) Passive network

(c) Resistive network

(d) Dummy network

Q46. When the load at the receiving end of a long transmission line is removed, the

Sending end voltage is less than the receiving end voltage. This effect is known as

(a) Ferranti effect

(b) Proximity effect

(c) Kelvin effect

(d) Faraday effect

Q47. A load draws an active power P at a lagging p.f. of cosϕ 1 . If the p.f. is improved to

cosϕ 2 , the leading kVAR supplied by p.f. correction equipment will be

(a)

(b)

(c)

(d)

Q48. Which of the following devices does not have negative resistance characteristics?

(a) UJT

(b) Tunnel diode

(c) SCR

(d) FET

Q49. A JEET has the following parameters: Calculate the drain current

(a) 0.6125 mA

(b) 61.25 mA

(c) 6.125 mA

(d) .06125 mA

Q50. In the state of saturation, a MOSFET acts as

(a) an amplifier

(b) an open switch

(c) pure resistor

(d) a closed switch

Q51. A 50 Hz, 3-phase induction motor has a full load speed of 1440 r.p.m. The number

of poles in the motor is

(a) 2-pole

(b) 4-pole

(c) 6-pole

(d) 8-pole

Q52. A three phase, 50 Hz induction motor has a full load speed of 1440 rpm. The full

load slip will be

(a) 3%

(b) 5%

(c) 4%

(d) 2%

Q53. Consider sinusoidal modulation in an AM system. Assuming no over modulation,

the modulation index (µ) when the maximum and minimum values of the envelope,

respectively, are 3V and 1V is….

(a) 0.33

(b) 0.5

(c) 1.0

(d) 1.5

Q54. The maximum power efficiency of an AM modulator is?

(a) 25%

(b) 33%

(c) 66%

(d) 100%

Q55. In the frequency modulation, if is the modulating frequency, of the maximum

frequency deviation and B is the bandwidth, then

(a)

(b)

(c)

(d)

Q56. In FM broadcast, maximum deviation is 75 kHz and maximum modulating

frequency is 15 kHz. In view of Carson’s rule, the required bandwidth is……

(a) 180 kHz

(b) 150 kHz

(c) 30 kHz

(d) 15 kHz

Q57. Calculate the minimum anode current required to turn off SCR if the latching

current value is 2 A.

(a) 2 A

(b) 3 A

(c) 4 A

(d) 5 A

Q58. The relation between drain current and gate source voltage in Enhancement

MOSFET in saturation region is

(a)

(b)

(c)

(d)

Q59. FET is a ___________ controlled device.

(a) current

(b) resistance

(c) impedance

(d) voltage

Q60. Which of the following is a universal gate for logic circuits?

(a) OR

(b) AND

(c) NOT

(d) NAND

Q61. Find out open loop transfer function of a unity feedback control system having

closed loop transfer function as

(a)

(b)

(c)

(d)

Q62. What is the open loop DC gain of a unity feedback control system having closed

loop transfer function as?

(a) 4/13

(b) 13/4

(c) 9/4

(d) 4/9

Q63. Lead compensator is used to improve ——————

(a) Transient response

(b) Steady state response

(c) Both a and b

(d) None of the above

Q64. The impulse response of a linear system is e -t , (t > 0). The corresponding transfer

function is

(a)

(b)

(c)

(d)

Q65. Frequency of oscillation of Colpitts’s oscillator is given by-

(a)

(b)

(c)

(d)

Q66. Fermi energy level for P-type extrinsic semiconductor lies….

(a) Close to valence band

(b) Close to conduction band

(c) At the middle of the band gap

(d) None of the above

Q67. The magnetic flux density and the vector magnetic potential A are related as

(a) = ∇ .

(b) = ∇ ×

(c) = ∇ ×

(d) = ∇ .

Q68. The ratio of charges stored by two metallic spheres raised to the same potential is

6. the ratio of the surface area of the sphere is

(a) 6

(b) 1/6

(c) 36

(d) 1/

Q69. Sound signals in TV are:

(a) Amplitude modulated

(b) Frequency modulated

(c) Dc modulated

(d) Both a and b

Q70. Video signals in TV are:

(a) Amplitude modulated

(b) Frequency modulated

(c) Dc modulated

(d) Both a and b

Q71. The modulation index of two different sinusoidal signal is 0.3 and 0.4. The resultant

Modulation index is

(a) 0.5

(b) 0.7

(c) 0.8

(d) 0.9

Q72. The modulation index of an AM wave is changed from 0 to 1 the transmitted power

is

(a) unchanged

(b) halved

(c) increased by 50

(d) Quadrupled

Q73. When supply voltage to a 3-phase squirrel cage induction motor is reduced by

20%, the maximum torque will decrease by

(a) 10 %

(b) 20%

(c) 36 %

(d) 40 %

Q74. A 10-bit D/A converter gives a maximum output of 10.23 V. the resolution is

(a) 25

(b) 20

(c) 15

(d) 10

Q75. A linear time invariant control system with unsatisfactory steady state error is to

be compensated. Which is/are the correct type of cascade compensation to be

provided?

1. Lead

2. Lag

3. Lag-lead

Select the correct answer using the codes given below:

(a) 1, 2 and 3

(b) 1 only

(c) 2 only

(d) 3 only

Q76. The number of address lines required to address a memory size of 16K is:

(a) 16

(b) 14

(c) 12

(d) 15

Q77. Skin effect occurs when a conductor carries current at………frequencies.

(a) Medium

(b) High

(c) Low

(d) Very low

Q78. Which of the following is the property of an ideal operational amplifier?

I. It should have an infinite input impedance.

II. It should have a zero-output impedance.

(a) Only I

(b) Only II

(c) Both I and II

(d) Neither I nor II

Q79. Which of the following statement is correct for the transformer?

I. It transfers electric energy from one circuit to another without a conducting link.

II. It converts energy without the change in frequency.

III. It is a combination of electrical circuits linked by common magnetic circuit.

(a) I and II

(b) I and III

(c) II and III

(d) I, II and III

Q80. A 200 KV transmission line has a maximum power transfer capacity of P. if it is

operated at 100 KV with the series reactance unchanged, then its power transfer

capacity is approximately

(a) P

(b) P/4

(c) 2P

(d) P/2

Q81. TRAP is

(a) Non-maskable, highest priority and hardware interrupt

(b) Maskable, highest priority and software interrupt

(c) Non-maskable, highest priority and software interrupt

(d) Maskable, lowest priority and hardware interrupt

Q82. ALE stands for

(a) Accumulator Logic Execution

(b) Arithmetic Logic Execution

(c) Address Latch Enable

(d) All enable

Q83. Calculate the minimum sampling rate to avoid aliasing when a continuous time

signal is given by: s(t)= 5 cos 200πt.

(a) 100 Hz

(b) 200 Hz

(c) 400 Hz

(d) 20 Hz

Q84. What is the cause of radio interference in communication lines?

(a) Electromagnetic induction

(b) Sunlight

(c) Ferranti effect

(d) Temperature change

Q85. Derive the Boolean expression for the logic circuit shown below:

(a)

(b)

(c)

(d)

Q86. If the Op-Amp in the figure is ideal, the output voltage V o will be equal to

(a) 1 V

(b) 6 V

(c) 14 V

(d) 17 V

Q87. An ideal Op-Amp is an ideal

(a) Voltage Controlled Current Source

(b) Voltage Controlled Voltage Source

(c) Current Controlled Current Source

(d) Current Controlled Voltage Source

Q88. The circuit in the figure is

(a) Low Pass Filter

(b) High Pass Filter

(c) Band Pass Filter

(d) Band Reject Filter

Q89. An n-channel JFET having a pinch-off voltage of shows a transconductance of 1 ,

when the applied Gate to source is . Its maximum transconductance is:

(a) 1.5

(b) 2.0

(c) 2.5

(d) 3.0

Q90. A SCR triggered by a current pulse through its gate can be turned off by

(a) by reversing the polarity of anode and cathode voltage.

(b) by giving pulse to the cathode.

(c) by giving pulse to anode.

(d) giving another pulse of the same polarity to the gate.

Q91. Match List-I (SCR rating) with List-II (Protective element) and select the correct

answer using the codes given below the lists:

List-I List-II

A. di/dt limit 1. Snubber

B. dv/dt limit 2. Heat Sink

C. t limit 3. Series reactor

D. Junction 4. Fuse

temperature limit

Codes:

A B C D

(a) 3 1 2 4

(b) 1 3 2 4

(c) 1 3 4 2

(d) 3 1 4 2

Q92. In the forward blocking region of a silicon-controlled rectifier, the SCR is

(a) Reverse biased

(b) In the on-state

(c) In the off-state

(d) at the point of breakdown

Q93. Match List-I (Semiconductor Device) with List-II(Application) and select the

correct answer using codes given below the lists:

List-I List-II

A. Triac 1. used in HVDC system

B. IGBT 2. used in pulse generation

C. SCR 3. used in motor control circuits

D. UJT 4. used in AC regulators

Codes:

A B C D

(a) 1 3 4 2

(b) 4 2 1 3

(c) 1 2 4 3

(d) 4 3 1 2

Q94. Which of the following does not cause permanent damage to an SCR?

(a) High current

(b) High rate of rise of voltage

(c) High temperature rise

(d) High rate of rise of current

Q95. Electrostatic instruments are suitable for the measurement of:

(a) ac and dc voltages

(b) ac voltage and current

(c) dc voltage and current

(d) an and dc current

Q96. The time constant of the circuit shown in fig. is:

(a) RC/3

(b) 4RC/3

(c) 2RC/3

(d) 8RC/3

Q97. In DC series motor, torque is proportional to which of the following? (Neglect

saturation)

(a) Flux(φ)

(b) Armature current (Ia)

(c) Both a and b

(d) None of the above

Q98. In a transformer maximum flux density is not constant, the eddy current loss

varies as

(a)

(b)

(c)

(d)

Q99. The relative speed between the stator magnetic field and rotor in the induction

motor is:

(a)

(b)

(c)

(d) 0

Q100. The relative speed between the stator magnetic field and stator in the induction

motor is…………

(a)

(b)

(c)

(d) 0

## UPPSC Polytechnic Lecturer Electrical Engineering Solution PDF

The candidates can check UPPSC Technical Lecturer Electrical Engineering Solution PDF through the direct link given below for the ease of candidates. The solutions are for most expected questions for Eletrical Engineering.

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