 2019 2020 2021 Student Forum National Thermal Power Corporation Limited placement papers of past years

#1
 Unregistered Guest National Thermal Power Corporation Limited placement papers of past years

Will you please share with me the National Thermal Power Corporation Limited placement papers of past years?
#2
 Super Moderator Join Date: Apr 2013 Re: National Thermal Power Corporation Limited placement papers of past years

As you want to get the National Thermal Power Corporation Limited placement papers of past years so here it is for you:

1. What is causal system?
2. Shunt reactor is used in EHV transmission line for
3. 20w, 40W, & 200w lamps are connected to three phases if neutral wire breaks then
which lamp will fuse first? 1) 20 2)40 3)200 three lamps will fuse together.
4. Synchronous machine can be operated at both lagging and leading power factor
5 What does synchronous speed mean?
6. Frequency of emf generated per rotation of rotor is equal to.
7. DC machine having wave winding is wounded as lap winding what will be the effect
on emf generated
8 Which is remain unchanged in transformer action?
9. In transformer windings are connected.?
10. In general how transformer is rated?
11. What is given on the name plate of motor? 1) KW 2) KVA 3) output shaft power
12. Short circuit test of transformer gives what?
13. Transformer core are laminated for what purpose?
14. What is supply voltage for heavy industry .1) 33KV 2) 11KV 3) 132 KV 4) 66KV
15. Basic structure SCR as a two transistor i.e. how they are connected?
16. What is Triac?
17. System admittance is (G+jB) what is reactive power absorbed if the voltage is V KV?
(1) V (square)*B (2) V (square)*g .
18. In series R-L circuit what is phase difference between the voltage drop across R and
L?
19. Power factor is cosine (delta ) delta is the angle between 1) phase voltage phase
current 2)
Line voltage lone current 3) phase voltage line current 4) line voltage phase current.
20. Laplace of exp (-at)?
21. For series R-L-C circuit the load will be capacitive if the frequency is 1) greater than
the resonant frequency 2) less than the resonant frequency 3).
22. In Wiens bridge which circuit elements determine the frequency range?
23. What is the output if two booster having duty cycle K and (K-1) are connected in
series?
24. If a DC shunt motor is loaded from unloaded condition what will be effect of on
terminal voltage?
25. A second wire system having one pole one right half of the s-plane. When the system
will be stable?
26. A system having repetitive pole what will be effect on the gain at the cross over
frequency?
27. Hollow conductor is used to reduce corona loss how does it reduce the loss?
28. In DC machine how voltage is related to flux?
29. Nature of current and voltage in the armature and at the terminal in DC machine.
30. Motor acts on the principle of ..rule
31. Which instrument measure both ac and dc?
32. How the rotation of induction motor is reversed?
33. If 3-phaseof a 3- phase balance load are reversed what will be the effect on the line
current?
34. If the rating of VAR absorber is 50MVAR at 400KV. What will the VAR absorbed
by the absorber at 300KV?
35. In regenerative breaking of DC series motor what is done?
36. Definitions of Fourier transform?
37. Laplace of f(t) is F(S) what is Laplace of f(t+T) .
38. Z-transform of sampled function x(n) for n>0.
39. Laplace transform of impulse function.
40. Z-transform of unity.
41. How many slip rings are there in 3phase synchronous motor?
42. How the speed of synchronous motor is controlled?
43. Speed control of induction motor?
44. When power supply is supplied to heater coil it glows while simple wire does not
glow. Why?
45. A synchronous generator having inertia constant 4 and having rating of 100MVA.
What will be energy stored by the machine?
46. A transformer having ratio 20:1. The secondary load is 0.6 ohm and the voltage
across it is 6 V what will be the primary current?
47. A RC circuit having r=0.8ohm, c=2.5micofarad what will be the time constant?
49. Two capacitors connected in series the equivalent capacitance is 0.03uf and when
connected in parallel the equivalent capacitance is 0.16uf find out the ratio of the two
capacitance?
50. An L-c circuit having frequency 1/sqrt (LC) what will the equivalent impedance?
51. An inverting op-am having input with resistance in series and a capacitance in
feedback operates as a.?
52. A current having fundamental and third harmonics what will be the rms value of the
current?
53. Peak to peak value of voltage if rms voltage is 100V.
54. Rms voltage.
55. What is the approx efficiency of nuclear power plant?
56. What is the average current of a single phase full wave rectifier firing at angle alpha?
57. What is the function of freewheeling diode?
58. When SCR stops conduction? (holding current)
59. For measuring current why shunt resistance is used?
60. For economic operation of plant what is the condition?(taking into account the
penalty factor)
61. Incremental fuel cost of two plants is given and a load is given. Find out the load
sharing for economic operation of the plant?
62. A two port network is represented by ABCD parameters. What will be condition for
the two port network to be symmetrical?
63. Size of the conductor is determined by .
64. Which Surface is suitable for grounding?
#3
 Unregistered Guest Re: National Thermal Power Corporation Limited placement papers of past years

Hi I am preparing for the placement of National Thermal Power Corporation Limited so can you please provide me the previous year placement paper?
#4
 Super Moderator Join Date: May 2012 Re: National Thermal Power Corporation Limited placement papers of past years

Ok, here I am providing you the placement paper of National Thermal Power Corporation Limited

NTPC placement paper

1. Expression for d(n): u(n)-u(n-1)/ u(n-1)-u(n+1)/ u(n)+u(n+1)/…

2. Numerical on a photodiode: to calculate the responsivity/sensitivity when a specified no of incident photons cause a specified no of electron generation.

3. For a radioactive sample which decays to 12.5% of its initial value in x days, the half life is given by..

4. Connect two 1o resistors in series, then connect two 1h inductors across one of the resistors such that the ckt looks like a 1o resistor in series with a ?-section of a resistor and two inductors. With the series resistance on the I/p side, calc the transfer function of this ckt

5. Ac signal conditioning is used for inductive and capacitive/resistive/piezoelectric transducers/all of the above.

6. Lower useful input limit of a transducer is determined by..

7. Air-cored inductors are used for low frequency/high frequency/equal frequency operations.

8. Given 4 pole-zero plots identify which one corresponds to the driving point impedance of a series resonant ckt.

9. Given four unit-circle plots identify the one corresponding to a bandpass filter.

10. The sequence (2,3,4,3) is circularly even/circularly odd/circularly zero/both circularly even and odd.

11. Z-transform of 3n u(n).

12. Match the following with their characteristics: led/lcd/nixie tube/optical fibre.

13. A 4 khz signal is sampled at thrice the nyquist rate and sent through a channel with error =1%. Calc the bandwidth of the channel.

14. Given an op-amp ckt obtain an expression for o/p voltage.

15. No. Of encirclements made about the origin of the nyquist plot of the open loop tf:1/[(s-1)(s+2)(s+3)].

16. Given a two port network in the form of a t find o/p admittance in terms of y-parameters.

17. For a repeater in a pcm cable identify the correct sequence of actions amongst threshold/equalization/etc.

18. O/p of a delta modulator when a ramp input is fed to it.

19. Steady state error with ramp I/p for a type-0 system.

20. Creeping occurs in energy meters bcoz…

21. Ultrasonic method of flow measurement cannot be used in liquids with air bubbles/has less attenuation in air compared to liquid-identify the false statement (if any) among these.

22. Major cause of losses in a fibre optic cable: dispersion/total internal refraction/presence of core and cladding/..

23. Which layer in the OSI model is concerned with printer buffering, etc: network/session/transport/..

24. Given some function f(j?) calculate its inverse ctft.

25. Relation between Laplace and z-transform: s=z/ s=ln z/ s=( ln z/t) /..

26. Maximum and minimum probability error among ask,psk,fsk,dpsk etc

27. Which of the following is a non linear modulation scheme: pam/qam/pcm/..?

28. Match the following functions: e-t , e-t + et, sin(pt) with causal and stable system, causal and unstable system, etc.

29. Given a ckt with a 50 o resistor in series between two voltage sources of 10 v and 5 v magnitude calc power delivered by 5 v source.

30. Laplace transform of e-3tu(t)+e2tu(-t).

31. Which photo detector has output affected by own intrinsic noise: pn/apd/pin/all.

32. Inverse Laplace transform of 1/s2[d/ds(e-3s/s)]

33. When I mode is added to proportional control system stability increases/ decreases/ steady state performance deteriorates/damping increases.

34. Reset control is another name for integral/derivative/proportional/… Control.

35. Time response of system having transfer function 625/(s2+25) will be of the form..

36. Given some transfer function calc the peak response time.

37. The nyquist sampling rate of the function [sin(at)/t]2 will be..

38. The feedback topology that results in increased I/p and o/p impedance is current series/voltage series/current shunt voltage shunt.

39. Numerical on cardiac output calculation given heart rate and volume per beat.

40. In an ecg instrumentation amplifier the differential gain is provided by 1st stage/2nd stage/mismatched resistors/output stage.

41. Repeat question 40 above for the classic 3-op amp instrument amplifier.

42. Emg signals are of the order of mv/v/µv/..

43. Computer assisted tomography is used for..

44. Numerical on electrostatic instrument, to calculate deflection given spring constant, torque etc.

45. To prevent loading of a ckt I/p impedance of a cro should bee high/low/inductive/capacitive.

46. Addition of a zero to a 2nd order underdamped system results in increase/decrease of rise time and increase/decrease of peak overshoot.

47. For pi ctrl we obtain improved bandwidth/improved steady state performance/ worsened steady state performance/
.
48. SNR of normal am system is comparable/3 db lower/3 db higher/6 db lower over dsb-sc and SSB system.

49. Which is an effective measure of the noise related performance of an amplifier: snr/noise ratio/thermal noise/shot noise?

50. Given baseband signal freq and carrier freq calc which of the freq given will not be present for conventional am.

51. Distinction between fm and pm at high frequencies.

52. Which of these has the least propagation delay rtl/ecl/i2l/cmos.

53 Switching speeds of CMOS is affected/unaffected by changes in supply voltage.

54. Which of these provides a measure of heart rate p/qrs complex/t/none of these.

55. Given a Circuit of a logarithmic amplifier you had to identify what ckt was it.

56. JFET can operate in depletion/enhancement/both/none of the above modes.

57. When a bjt operates in saturation the junctions are fwd biased/reverse biased/..

58. Bibo stability criterion implies that poles are within/outside/on the unit circle.

59. For faithful amplification of low amplitude signals the cut-off/active/saturation regions of a transistor is used.

60. Lissajous pattern of a signal rotates 36 times per minute. If the oscillator frequency is 560 KHz then the unknown freq is..

61. % Resolution of a 10 bit adc.

62. To obtain 10 mv resolution on 5 v range how many bit dac is to be used..

63. Why is lcd preferred to led.

64. How will 0.6973 be displayed on 10 v range of a 4 ½ digit multimeter.

65. Which of the following cannot be used for an automatic feedback temp ctrl system thermocouple/thermometer/ Thermistor /ic sensor.

66. Y(n)=x(-n+3) is an example of a linear/non linear and shift variant/invariant system.

67. The falling body method is used to determine viscosity/humidity/…

68. Which of these methods of viscosity measurement gives greatest accuracy falling body method/rotating cylinder method/both/..?

69. Some question on gas chromatography

70.A device having a rotor with 3 y-connected coils and a stator is likely to be a synchro/rvdt/control transformer/..

71. In a twisted ring counter the initial count is 1000. After the 4th clock pulse its state will be…

72. A 240 khz signal is given into a 3 bit binary ripple counter. The lowest o/p freq obtainable is…

73. For parity bit checking which of the following gates can be used xor/nand/or/xnor.

74. Why is a BJT called so..

75. Identify the expression for gauge factor of a strain gauge among the given options.

76. In a semiconductor strain gauge as tensile strain is applied what changes take place in the n and p areas..

77. How does a radioactive level gauging system work..

78. A capacitive transducer measuring level works on the principle of change in distance between plates/change in dielectric strength/..

79. For maximum power transfer in an ac circuit the condition to be satisfied is zl+zs=0/xl+xs=0/none of these/…where l and s refers to load and source resp.

80. Find the transfer function from a block diagram.

81. Synchronous ctrs are preferred to asynchronous ctrs bcoz they are faster/glitches at the output can be avoided/both/none of these.

82. The lissajous figure formed on an oscilloscope looks like the english figure of 8. If the vertical channel input is 1 khz the horizontal input freq is…

83. Ie=ic for a transistor in saturation/cutoff/active/both saturation and active regions.

84. Reproducibility of measurements is called accuracy/precision/linearity/none of these.

85. Which of these is not strictly a static characteristic accuracy/precision/tolerance/linearity.

86. The shunt coil in a q meter has resistance of the order of mo/o/ko/..

87. For measuring inductance of high q coils the bridge used is maxwell-wien/schering/..

88. Which of these measures inductance in terms of capacitance maxwell and hay/maxwell and schering/hay and schering/..

89. In a flip-flop with preset and clear inputs both are applied simultaneously/clear is cleared when preset is applied/preset is cleared when clear is applied/…

90. What happens when the ret instruction is encountered by 8085

91. A 1024*8 memory chip needs how many address lines..

92. What happens when the push instruction is encountered by 8051.

93. In fm relation between no of sidebands w.r.t. Modulating freq Quick Reply

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