QP ESPE26 ElecEngg II 09022026

Engineering Services (Preliminary) Examination, 2026 DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE TOLD TO DO SO T.B.C. : RSPV-T-NLEE Test Booklet Series Serial No. 1007869 TEST BOOKLET PAPER—II ( Electrical Engineering ) Time Allowed : Three Hours Maximum Marks : 300 . You have to enter your Roll Number on the Test Booklet in INSTRUCTIONS . IMMEDIATELY AFTER THE COMMENCEMENT OF THE EXAMINATION, YOU SHOULD CHECK THAT THIS TEST BOOKLET DOES NOT HAVE ANY UNPRINTED OR TORN OR MISSING PAGES OR ITEMS, ETC. IF SO, GET IT REPLACED BY A COMPLETE TEST BOOKLET. . Please note that it is the candidate’s responsibility to encode and fill in the Roll Number and Test Booklet Series A, B, C or D carefully and without any omission or discrepancy at the appropriate places in the OMR Answer Sheet. Any omission/discrepancy will render the Answer Sheet liable for rejection. the Box provided alongside. DO NOT write anything else on the Test Booklet. . This Test Booklet contains 150 items (questions). Each item comprises four responses (answers). You will select the response which you want to mark on the Answer Sheet. In case you feel that there is more than one correct response, mark the response which you consider the best. In any case, choose ONLY ONE response for each item. . You have to mark all your responses ONLY on the separate Answer Sheet provided. See directions in the Answer Sheet. . All items carry equal marks. . Before you proceed to mark in the Answer Sheet the response to various items in the Test Booklet, you have to fill in some particulars in the Answer Sheet as per instructions sent to you with your Admission Certificate. . After you have completed filling in all your responses on the Answer Sheet and the examination has concluded, you should hand over to the Invigilator only the Answer Sheet. You are permitted to take away with you the Test Booklet. . Sheets for rough work are appended in the Test Booklet at the end. 10. Penalty for wrong answers : THERE WILL BE PENALTY FOR WRONG ANSWERS MARKED BY A CANDIDATE. (i) There are four alternatives for the answer to every question. For each question for which a wrong answer has been given by the candidate, one-third of the marks assigned to that question will be deducted as penalty. (ii) If a candidate gives more than one answer, it will be treated as a wrong answer even if one of the given answers happens to be correct and there will be same penalty as above to that question. (iii) If a question is left blank, i.e., no answer is given by the candidate, there will be no penalty for that question. DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE TOLD TO DO SO 1. Consider the following characteristics regarding ideal operational amplifier : 1. An infinite output impedance and zero input impedance 2. The Op-Amp must have an extremely high inherent voltage gain 3. Zero slew rate Which of the above characteristics is/are correct? (a) 1 and 3 (b) 3 only (c) 2 only (d) 1 and 2 2. An inverting amplifier using the 741C must have a flat response up to 40 kHz. The gain of the amplifier is 10. What maximum peak-to-peak input signal can be applied without distorting the output? (a) 0:398 V (b) 3:98 V (c) 30:98 V (@) 0:0398 V RSPV-T-NLEE/63A 3. Consider the following statements regarding bistable multivibrator : 1. The bistable multivibrator is used as memory elements in_ shift registers, counters. 2. It is used to generate sine wave by sending regular triggering pulse to the input. 3. It can also be used as a frequency divider. Which of the above statements is/are correct? (a) 1 and 3 (b) 3 only (c) 2 only (a) 1 and 2 4. What is the percentage of resolution of the eight-bit DAC? (a) 0:0244% (b) 0:392% (c) 0:568% (a) 0:0148% 5. What is the value of the capacitance to use in a capacitor filter connected to a full-wave rectifier operating at a standard aircraft power frequency of 400 Hz, if the ripple factor is 10% for a load of 500 Q? (a) 72:2 uF (b) 87-6 uF (c) 25-2 uF (d) 102-4 uF 6. Match the following Lists regarding R-C filter circuit : List-I [Component] P. Low-pass filter Q. R-C circuit as integrator R. High-pass filter S. R-C circuit as differentiator 7456-17 [Output voltage (01) 1 ا‎ நங்க @RC +2 av, dt 1 ‌ +2 Select the correct answer using the code given below. 4 3 0 1 8 4 1 9 2 1 RSPV-T-NLEE/63A R 5 2 1 R 5 2 4 R 5 2 3 R 5 4 3 7. Match the following Lists : List-I (Name of the flag) 7156 77 (Bit position in flag register) P. Auxiliary carry flag 1. Do Q. Parity flag 2. 722 R. Zero flag 3. Dg S. Carry flag + ‎ Select the correct answer using the code given below. 2 | P 9 5 1⁄0 1. 2 (9 2 () 9 1 8. Match the following Lists regarding interfacing the 8155 memory section : List-I List-IT (Address lines) (Function used for) P. All to &15 1. Don’t Care Q. AO to A7 2. Chip Enable . A8 1 0 3. Register Select Select the correct answer using the code given below. 8 87 0 OR ‎ 310 ; ‎ A [ P.T.O. 9. The emission current of a diode is 12:5 mA. What is the rms value of shot noise current for a 10 MHz bandwidth? 12. - The signal voltage and noise voltage of a system are 0°923mV and 0:267 mV respectively. What is the signal-to-noise ratio (SNR) in number? (a) 18-2 pA (b) 1:3 pA (a) 3-45 (c) 0-2 pA (b) 10°77 ils cies (c) 0-29 10. A eandinites supplies 10 kW power to (a) 11-95 an aerial, when unmodulated. What is the power radiated, when modulated to 30%? 13. Match the following Lists regarding (a) 3 kW sampling techniques : (b) 10-45 kw List-I List-IT : (Sampling (Principle) (c) 14:8 kw ieciramie) da) 4kW (a) P. Natural 1. It uses sample-hold sampling principle 11. Consider the following statements regarding AM versus FM broadcasting : Q. Flat-top 2. It uses multiplication sampling 1. The process of demodulation is eee complex in AM broadcasting than R. Ideal : 3. It uses multiplication or sampling chopping principle that of in FM broadcasting. 2. In FM broadcasting, stereophonic transmission is possible. Select the correct answer using the code given below. 3. The AM broadcasting system has poor noise performance. (a) P Q R 2 3 a Which of the above statements is/are correct? (b) P Q R 1 3 2 (a) 2 and 3 (b) 3 only (¢) 4 : . (c) 1 only (a) P Q R (q) 1 and 2 3 2 1 RSPV-T-NLEE/63A 4 14. The diode falls under which type of 16. The signal space should be divided as system? (a) periodic only, whereas the system should be either time scaling or shifting (a) Stable only ; (b) non-periodic only, whereas the system should be time shifting (b) Unstable only (c) either periodic or non-periodic, whereas the system should be either time scaling or shifting (c) Either stable or unstable (d) neither periodic nor non-periodic, whereas the system should be time scaling (d) Neither stable nor unstable 17. Consider a non-recursive filter with the impulse response h(n) shown in the figure below : h(n) 15. Which of the following properties of convolution system exhibits/exhibit the result of superposition principle for unit impulse response in linear time- 1 invariant systems? a ” (a) Commutativity only What is the group delay in terms of frequency? (b) Distributivity only eet (a) 1 (c) Associativity only (b) 2 (c) 3 (a) Both distributivity and associativity (da) 4 RSPV-T-NLEE/63A 5 [EetO? 18. If A(t) = [-2 2142.672 feo +&(), then 21. Consider a finite-duration sequence such 3 3 as x(n) = , 2, 4, 8 16). What is the the function is new sequence produced, when 11 revolves 4 units in the circular shift (a) causal and stable operation? (b) non-causal and stable (a) 6 319,271 ( causal and unstable (0) {2, 4, 8, 16, 1} 2 (0) non-causal and unstable () a, 2, 4, 8, 16} (0 {16, 1, 2, +, 8} 19. The unit impulse response of an LTI 1 system is 1 = € 1 sin2tu(t). What is the response to x(t) = sin(t) by using the 22. What is the convolution response Laplace transform? y(5) of the given sequence? (a) y(t) = sin(2t) ), 05755 x(n) = 4/3 3 10026 0 » elsewhere sin t) = ©) 0 ‎ and h(n) = 2 3 2 1} ( y(t) =0-447sin(t) (a) 0 () y(t) = 0-447sin(t -26-6°) (b) 9 ( 14 „900 1 (0) 28 x(n) = {.., 0, 0, } 1.41 5 0 0....) 23. By using the 3-point DFT of the sequence h(n) =a", 0 < 7 < 2, for a = 1. 369, what is the relationship between the output what is the value of y(n) = x(2n)? ? sequences? () y(n) = x(2n) + x(n) (a) H(0)+ H() + 77(2) = 4 (b) y(n) = () ¬ ‎ ¬ 7) (0) ` 2(0) + &(1) = HQ) (© y(n) = 09 - 01-4) (0 20) = H(2) () y(n) = x(n) ¬ ×(7 ¬ 7) () 10) = H*() RSPV-T-NLEE/63A 6 24. If X(s) = L{x(t)}, what is the initial value 20) and the final value’ 2059) respectively, for the given signal X(s) = 7576 , using initial value and s(3s + 5) final value theorems? 9. (7 =, = (a) 5 3 7 (b) 2, 7 =, 2 (6) 3 16 ) , (0) 3° 25. 1 X(s)=L{x(t)}, what is the inverse Laplace transform of 106 signal 5(5 + ])(+ 2) (a) x(t) = (0.5-267" + tet + 1:56 2040 (0) x(t) = (0-5-2 + tet 42 y(t) (0 x(t) (0-5-67! + ( 2 +2e7- () x(t)=(1-e* 41 2048 26. What is the DC gain (zero frequency) for a system which has a transfer function of G(s) = (5 + 2) /((s+ 1)(5 + 3)( + 4))? (a) 1/6 (b) 2/3 © 1/3 () 1/2 RSPV-T-NLEE/63A 27. Match the following Lists : List-I List-IT (Input function) (Use) . 1. Steady-state error ©. u(t) 2. Transient response . 511000 3. Transient response steady-state error : (1 /2)t? u(t) 4. Transient response modeling steady- state error Select the correct answer using the code given below. (00 ) 1 42 ‎ (b) @: [RSs . 1 5: 3 ] 23 "POT ஆடம்‌ De 71‎ 28. Consider the following steps regarding multiple-node electrical networks : 1. Replace passive elements’ values with their admittance 2. Replace all sources and time variables with their Laplace transform 3. Replace transformed voltage sources with transformed current sources Which of the above steps are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and3 [ P.T.O. 29. What is the transfer function 7(s) from the state-space input matrix x=[A]x+[B]u and output matrix y=([C]x, where T(s) = Y(s)/U(s), while U(s) is input and Y(s) is output? OFs Al: te] 10 x=| 0 O Ilix+!] Ow; y=[1 0 Ox -1 -2 -3 0 a (a) Ts) = ae +3s+2) s? +3s74+2s+1 10(s? + 3s +2) He PS tec 2 () Ts) = s +3s+2) s? +6s7 +5s+1 10(s? + 3s+2 (a) Te <e s° +2s* +3s+1 30. Consider the following statements regarding first-order systems : 1. The time constant of the system can be described as the time for e-* to decay to 63% of initial value or it is the time taken for the step response to rise to 37% of its final value. 2. Rise time is found to be the time for waveform to go from 0:1 to 0:9 of its final value. 3. Settling time is defined as the time for the response to reach and stay within 4% of its final value. Which of the above statements is/are not correct? (a) 1 only (b) 2 (c) 3 only (?) l1and3 RSPV-T-NLEE/63A - Consider the following statements regarding behavior of second-order underdamped system : 1. The’ peak time is_ inversely proportional to the imaginary part of the complex pole. 2. Percent overload is a function of only the damping ratio. 3. Settling time is directly proportional to the real part of the complex pole. Which of the above statements are correct? (a) 1 and 3 only (b) 1,2 and 3 (c) 1 and 2 only (d) 2 and 3 only 32. For the closed-loop transfer function given below, what is the system condition based on the number of poles in the left-half plane, the right-half plane and the jaaxis? 200 s+ +6s3 +11s? +6s+200 T(s) = (a) The system is stable with four poles on the left-half of the plane. (b) The system is unstable, since it has two right-half plane poles and two left-half plane poles. (c) The system is marginally stable, since it has two left-half plane poles and two on jw-axis. (d) The system is unstable, since it has one right-half plane pole and three left-half plane poles. 33. Consider the following statements regarding stability for linear, time- invariant systems using natural response : 1. A-system is marginally stable, if the natural response neither decays nor grows but remains constant or oscillates. 2. Asystem is unstable, if the natural response approaches infinity as time approaches zero. 3. A system is unstable, if any bounded input yields an unbounded output. Which of the above statements is/are not correct? (a) 1 only (b) 2 only (c) 3 only (d) 1,2 and3 34. What are the values of positive constant (Kp), velocity constant (K,) and acceleration constant (Kq) for a type ‘0’ unity feedback system which has the 1000(s + 8) transfer function G(s) = —————— (s+ 7)(s+9) (a) K, =0; K, =0; Kg =127 (b) K (c) Kp =0; K, =127; K, =127 i) fo} ; K, =0; Ka =0 as} (d) K p= 127; K,=0; Kg =0 RSPV-T-NLEE/63A 35. Consider the following statements regarding properties of a _ transfer function : 1. The unit of a transfer function is related to the units of the system input and output. A unit is essential. 2. The transfer function can be applied to describe only time-invariant linear systems whose parameters do not change or change only a little during operation. 3. The transfer function is dependent of the input to the system, since the characteristics of the system are modified by the input signal. Which of the above statements is/are correct? (a) 1,2 and 3 (b) 1 and 3 only (c) 2 and 3 only (d) 2 only 36. Consider the following and give the order of the steps to be followed in performing the block diagram reduction to get the final transfer function for that system : Step 1 : Combine all serial blocks Step 2: Close all inner loops Step 3 : Combine all parallel blocks Step 4: Move summing junctions to the left or right of a block and tie points to the left or right Select the correct sequence for the above steps. (a) Step 1, Step 2, Step 3, Step 4 (b) Step 1, Step 3, Step 2, Step 4 (c) Step 3, Step 2, Step 1, Step 4 (d) Step 2, Step 3, Step 1, Step 4 [ P.T.O. 37. Consider the following statements regarding representation of block diagrams through signal flow diagrams : 1. The signal at a node is equal to the sum of all signals transmitted to the node. Sometimes, the transmittance may be positive. 2. The transmittances are simply related to the transfer functions. 3. The transmittances connected to the input/output nodes are both unity; and merely help to make the diagram clearer. Which of the above statements is/are correct? (a) 2 and 3 (b) 1 and 3 (c) 1 and 2 (d) 1 only Consider the following statements regarding Nyquist stability criterion : 1. The Nyquist stability criterion is one of the geometric criterion and graphical method in frequency domain. 2. It uses open-loop Nyquist diagram to judge the stability of the closed- loop system. 3. Instead of solving the characteristic roots of the open-loop system, the Nyquist criterion gets the stability of the closed-loop system by means of an open-loop frequency characteristic diagram. Which of the above statements are correct? (a) 1, 2 and 3 (b) 1 and 3 only (c) 1 and 2 only (da) 2 and 3 only RSPV-T-NLEE/63A 10 39. A transformer on no load has a core loss of 50 W, draws a current of 2A (rms) and has an induced emf of 230 V (rms). What is the core loss current? (a) 0-216 A (b) 1:988 A (c) 2:328 A (d) 0-456 A 40. A 500 kVA transformer has an efficiency of 95% at full load and also at 60% of full load; both at unity power factor. Separate out the losses of the transformer. (a) P, =12-42kW and P, =18-52kW (b) P, =2-45kW and P, = 8-35kW (c) P, =8-43kW and P, = 13-25kW (d) P, =9-87kW and P, =16-45kW 41. Consider the following statements regarding three-phase transformer connections : 1. Delta/delta is economical for small HV transformers. 2. Star/star suits large LV transformers. 3. Star/delta is the most commonly used connection for power systems. Which of the above statements is/are correct? | (a) 2 and 3 (b) 3 only (c) 1 only (qd) 1 and 2 42. A 240 V/120 V, 12 kVA transformer has 44. For a 6-pole DC armature with 16 slots full-load unity power factor efficiency of having two coil sides per slot and 96:2%. It is connected as an auto- single-turn coils, what is the transformer to feed a load at 360V. commutator pitch (y,) for a wave What is the auto-transformer rating? winding? (a) 8 segments : aa (b) 9 segments (b) 18 kVA (c) 6 segments (d) 5 segments (c) 54 kVA 45. Consider the following statements regarding speed control of DC motors : (d) 34-63 kVA 1. In field control method, speeds higher than the rated speed cannot be obtained. 2. For motors requiring a wide range of speed control, field control method leads to unstable operating conditions or poor commutation. 43. The magnetic flux density on the surface of an iron face is 1:6T, which is a typical saturation level value for ferromagnetic material. What is the sive Hanity on Paeeen. Eee? 3. Field control method is not suited to applications needing speed reversal. (a) 16x10 N/m? Which of the above statements is/are correct? (b) 1:02 x10° N/m? (a) 2 and 3 3 () 102x107 N/m? (b) 3 only (c) 1 only (d) 1-6x107 N/m? (dj. 1 ails 2 RSPV-T-NLEE/63A 11 [PEG 46. Which one of the following is not the remedy for reducing cross-magnetizing effect of the armature reaction? 48. A 0:5 hp, 6-pole induction motor is excited by a 3-phase, 60 Hz source. If the full-load speed is 1140 rpm, what is the percentage of slip? (a) Introducing saturation in the teeth (a) 6% and pole shoe (b) 12%. 9 (b) By chamfering the pole shoes a which increases the air gap at the (a) 3% pole tips 49. A 50 Hz induction motor wound for pole-amplitude modulation has 20 initial poles and the modulating function has 8 poles. At what two speeds will the motor run? (c) By making the field circuit resistance more than the critical value (a) Compensating the armature reaction mmf by a compensating winding located in the pole shoes (a) 300 rpm and 214-286 rpm (b) 400 rpm and 318-524 rpm (c) 150 rpm and 414-495 rpm (a) 450 rpm and 115-359 rpm 47. The total iron losses in the armature of a DC machine running at 875 rpm are 1100 W. What is the approximate braking torque due to iron losses? 50. A 3-phase synchronous _ generator produces an open-circuit line voltage of 6928 V, when the DC exciting current is 50 A. The AC terminals are then short- circuited and the three line currents are (a) 8 N-m found to be 800A. What is the synchronous reactance per phase? 16-42 N-m id (a) 1385 Q b) 862 (c) 885 N-m () () 802 (a) 12 N-m () 52 RSPV-T-NLEE/63A 12 51. Consider the following advantages of hydrogen cooling of alternators in steam power generation : 52. ono id Less noise due to the lower density of hydrogen Ventilation losses (fan power absorbed) are higher by 10% The heat transfer is more than that of air Which of the above advantages is/are correct? (a) (b) (c) (d) 2 and 3 2 only 1 only 1 and 3 Match the following Lists regarding Surge Impedance Loading (SIL) of AC lines : List-I List-II [Conductor configuration [SIL (MW)/ and line voltage] Quad Bersimis—400 kV 1. 647 Twin Moose—400 kV 2. 605 Quad Zebra—400 kV 3. 691 Triple Snowbird—400 kV 4. 515 Select the correct answer using the code given below. (a) P Q R iS 3 4 1 2 (b) P Q R Ss 2 1 4 3 ior Q R Ss} 1 4 2 3 (da) P Q R Ss 4 3 2 1 RSPV-T-NLEE/63A 13 SS34Ib ad is the distance between the conductors and e is the Euler’s number, then the maximum critical disruptive voltage occurs when the radius (r) of the conductors is (a) (b) (c) (a) dxe d/(l-@ d/e d/(1+e) 54. Match the following Lists regarding cable conductors : List-I List-II (Property) (Value) P. Specific gravity of i, 95 kg/mm? copper Q. Ultimate tensile 2. 8-890 strength of copper R. Specific gravity of 3. 40 kg/mm? aluminium S. Ultimate tensile 4. 2:71 strength of aluminium Select the correct answer using the code given below. (a) (b) (¢) (a) EosOe RS Se 4 ae 29 Pee Ora sR. SS OMe 480d peso. Re Ss Terre 45 12 Po (ORs aie 2 ees [ P.T.O. 55. Match the following Lists regarding percentage distribution of faults in various elements of a power system : List-I (Element) (% of total faults) P. Overhead lines 8] Q. Underground cables 2. 0 . Transformers : 7: S. Generators 48, . Select the correct answer using the code given below. fa): P Q R 5 4 3 1 ‎ 1 ~ 443 ୨୮୮୬ ୦ eR ୨ . 113 SP 2 1] 56. For a 735 kV line with a fault current of 4kA, what is the arc resistance? (Assume no resistance in the ground return path) (a) 4 (b) 8Q . 183-75 (0) 0-183 RSPV-T-NLEE/63A 14 57. Consider ‘the following statements regarding static relays compared with electromechanical relays : 1. In static relays, frequent operations cause deterioration. 2. In static relays, there is a quick resetting and absence of overshoot. 3. Static relays are sensitive to voltage transients. Which of the above statements is/are correct? (a) 2 and 3 (b) 2 only (c) 1 only (0 1 and3 58. What is the maximum value of restriking voltage across the contacts of the circuit breaker in a 132 kV system? (a) 107-78 kV ) 21556 kV ( 93:35 kV () 186-64 kv 59. Consider the following statements regarding radial distribution system : 1. Distributor far away from the substation is highly loaded. 2. Severe voltage variation to the consumers nearest to the substation is due to load variations. 3. Consumers are dependent on a single feeder and a single distributor, and a fault on either of them causes interruption of supply to all the consumers away from the fault. Which of the above statements is/are correct? (a) 2 and 3 (b) 3 only (c) 1 only (a) 1 and 3 60. Match the following Lists regarding bus classifications : List-I List-II (Bus type) (Quantities to be obtained) P. Generator bus 1. Real power, reactive power Q. Load bus 2. Reactive power, phase angle R. Slack bus 3. Voltage magnitude, phase angle Select the correct answer using the code given below. i@2P* 0 = De Se ae (b) P O° Ae Be OPT Mek 20 . R pat Ss igce, QO. fae Stan RSPV-T-NLEE/63A 15 61. Consider the following statements with respect to the change in torque angle whenever a disturbance occurs : 1. There is no change in torque angle when the speed of the rotor is the synchronous speed. 2. The angle decreases in case of a ious cit Pe > Pe, ee... tae mechanical output is more than the electrical input and the speed goes down. 3. The angle increases, if the speed is more than the synchronous speed. Which of the above statements is/are correct? (a) 2 and 3 (b) 3 only (c) 1 only (d) 1 and 3 62. Which one of the following is not a feature of ideal control system for an HVDC converter? (a) Control should be such that it should require less reactive power. The DC current is constant, i.e., ripple-free. (b) (c) Under steady-state conditions, the valve must be fired symmetrically. There should have continuous operating range from full rectification to full inversion. (a) [P.7.0. 63. Consider the following statements 65. Which of the following is not a limitation regarding Static Synchronous of MOSFET? Compensator (STATCOM) : (a) High on-state drop, as high as 10 V 1. It is insensitive to transmission system harmonics. (b) Unipolar voltage device 2. It has difficulty in operating with a (c) Slower switching speed very weak AC system. (ad) Lower off-state voltage capability 3. It can be used for small amount of energy storage. 66. Two BJTs are connected in parallel to share the total current 25A. The Which of the above statements is/are fi collector-to-emitter voltage of T; and T, correct? are 1:5 V and 1:75 V respectively. What (a) 2 and 3 is the difference in emitter current sharing by the two transistors, when the (b) 3 only current-sharing series resistances are Rp = 0-25 Q and Rpg = 0-35 Q? fc) 1 onk @) # (a) OSA (a) 1 and 3 (b) SA 64. A diode circuit consists of a diode in ane aa series with switch (S,), resistance d) 254A (R = 44 Q) and capacitance (C= 0-1pF). (@) The capacitor has an initial voltage Veo = Vo(t = 0) =220V. If switch S, is closed at t=0, what is the energy 67. The typical upper ratings of power dissipated in the resistor R? transistor (MOSFET) are (a) 3-86 mJ (a) 600 V/40 A (b) 5 mJ (b) 800 V/40 A (c) 139-64 mJ (c) 1000 V/50 A (da) 2:42 mJ (ad) 1200 V/SOA RSPV-T-NLEE/63A 16 68. The firing frequency of relaxation oscillator is varied by changing the value of charging resistance R. What are the maximum and minimum values of R? (Assume 7=0-65, I, = 0-65 mA, Vp =12V, 1I,=2:0mA, V,=1-5V, Veg =20V and C= 0-047 pF) (@) Ryin = 9°25kQ and Rmax = 12-3076 kQ (6) Rinin = 835 Q and Rmax =4°5kQ (c) Rmin = 425 Q and Rinax = 18-2469 kQ (@) Rin = 11-86kQ and Rmax = 19:2751kQ 69. The capacitance (C;,) value of reverse- biased junction J2 of a thyristor is independent of off-state voltage. The limit value of the charging current to turn the thyristor is about 15 mA. If the critical value of du/dt is 750 V/s, what is the value of the junction capacitance (Cy2)? (a) 200 pF (b) 200 pF (c) 50 pF (@) 50 uF RSPV-T-NLEE/63A 17 70. A_ single-phase, half-wave controlled rectifier with R load is supplied from a 230V, 50Hz AC source. When the average DC output voltage is 50% of maximum possible average DC output voltage, what are the firing angle of thyristor and average DC output voltage respectively? (a) 45° and 37-32 V (b) 90° and 36°61 V (c) 90° and 51:78 V (d) 45° and 26:39 V 71. A single-phase semi-converter is supplied by 200 V, 50 Hz and it is connected with an R-L-E load, where R=15Q, E=80V and L is very large so that the load current is ripple-free. What is the average output current at a = 90°? (a) 558A (b) 395A (c) 066A (d) 0:24 A [ P.T.O. 72. A step-down chopper has a_ load resistance of 20 Q and input DC voltage is 200 V. When the chopper switch is ‘on’, the voltage across semiconductor switch is 2 V. If the chopping frequency is 1-5 kHz and duty ratio is 40%, what is the average DC output voltage? (a) 40V (b) 80V (c) 396V (a) 1744V 73. What is the expression for distortion factor (DF) in inverters? (a) % v.72 [Pi gaits oe (“| (b) DF= ° v.27 [Ba 3.45; 0. (=) (c) DF= ¥ a va Pt [2e-2 3, 4uSic. (“)| (a) DF= . RSPV-T-NLEE/63A 18 74. A separately excited DC motor is controlled by a_ single-phase full converter which is supplied from 440 V, 50 Hz AC supply. If the field circuit is fed through a_ single-phase full converter with 0° firing angle, the delay angle of armature converter is 30° and load current is 20 A, what is the field current? (Assume that the armature resistance R, =0-5Q, field resistance Ry = 140 Q, and the current waveforms are ripple-free) (a) 2:83 A (b) 20A (c) 20:19 A (2) O79 A 75. Consider the following statements regarding AC drives : 1. AC drives require simple control algorithms than DC drives. 2. Power converters used in AC drives are relatively simple and less expensive. 3. VSI, CSI, AC voltage controllers, PWM inverters are used in variable speed induction motor drives. Which of the above statements is/are correct? (a) 2 and 3 (b) 3 only (c) 1 only (d) 1and3 76. A box contains 10 screws, three of which 79. If the events A and B are such are defective. If two screws are drawn at that P(A)=0-6, P(B)=0-2 and random without replacement, then what P(AUB) =0-7, then P(B|A) is is the probability that neither of the two screws is defective? (a) 1/4 (a) 49/100 (b) 1/6 (b) 14/30 (c) 9/10 (¢) one (a) 2/3 (a) 1/7 77. If the random variable X, which is the sum of the two numbers of two fair dice turned up, is discrete, then what is the probability of sum of at least 4 and at 80. If X ~ Binomial (16, d, then what is the variance of the random variable? most 8? (@) 8 (a) 26/36 (b) 1/6 me (c) 23/36 a (a) 1/12 (d) 6 78. A bag contains 7 green and 5 yellow balls. Two balls are selected at random, 81. If X ~ N(15, 6-25), then what is the value one at a time. What is the probability that the two balls are of different colours, if the selection is made with replacement? (a) 5/12 (b) 37/72 (c) 5/72 (a) 35/72 RSPV-T-NLEE/63A of X, which is 1-2 standard deviations below the mean? (a) 12 (b) 15 (c) 16 (a) 14 [ P.T.O. 82. Ifthe height h in metres of a swing above 85. What is the value of the Fourier coefficient a) for the function given the ground at time t seconds is given by h=2-1-5sint for 0<t<3, then the maximum height of the swing is (a) 4m (b) 1:79 m (it 2m (i) 6m 83. Consider the following statements regarding rank in terms of column vectors : 1. The rank r of a matrix A equals the maximum number of linearly independent column vectors of A. 2. The matrix A and its transpose AL, have the same rank. 3. Consider p vectors each having n components; if n< p, then these vectors are linearly independent. Which of the above statements is/are not correct? (a) 1 and 2 (b) 1 and 3 (ce) 2 and 3 (a) 3 only 84. The eigenvector X; of the nxn matrix A, corresponding to the eigenvalues A =A,, is a solution of the homogeneous equation, if (a) (A-A;DX; =0 (b) A-2,1=0 (c) (A+A;DX; =1 (d) A-A,I=1 RSPV-T-NLEE/63A 20 below? : -1 sin2x, -™1<x< y f=i 0, Fsxso sin2x, O<x<1 (a) 1/(2n) (b) ijn (c) 3/(4n) (d) 2/n 86. The straight line r(t) = ati+ btj+ ctk+C, with a, b and cas scalar constants and C as a constant vector, has (a) (b) (c) (a) a finite radius of curvature at every point zero radius of curvature at every point an infinite radius of curvature at every point an infinite radius of curvature at a single point 87. Consider the following statements regarding properties of eigenvalues : 1. Any square matrix A and its transpose A’ have the eigenvalues. same 2. The eigenvalues of a triangular matrix are just the diagonal elements of the matrix. 3. The sum of the eigenvalues of a matrix is the product of the elements of the principal diagonal. Which of the above statements are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (ad) 1,2 and 3 88. Let rbe the rank for the coefficient matrix A of the system of homogeneous linear equations having m number of equations and n number of variables. 1. If r<n, then the equations have (n-r) linearly independent solutions. 2. Ifm<vn, the number of solutions is finite. 3. If m=n, then such solution is non-trivial solution. Which of the above statements is/are not correct? (a) 1 and 2 (b) 2 only (c) 1 only (d) 2 and 3 RSPV-T-NLEE/63A 21 Consider the regarding atomic bonds : following statements 1. If two ions with same ionization potential form a bond, then this bond will most probably be ionic. 2. With the increase in the difference of the ionization potentials, the bond will be more and more ionic. 3. If the atom or molecule has completely filled outer shell, then the bonding between the atoms or molecules will be a primary bond at the time of solidification. Which of the above statements is/are correct? (a) 1 and 2 (b) 2 only (c) 3 only (da) 2 and 3 90. Match the following Lists : List-I List-I (Metal) (Resistivity) Prali 1. 434x108 Qm Q. Na 2. 1:56x10% Qm R. Cu 3. 833x108 Qm S. Ag 4. 147x108 Qm Select the correct answer using the code given below. (aq) 280, CRs Se an 24 1 (b) P 0. eRe Bi ae wtogn ie (ji Be On RS Sa Pe uo ee (abi. Rs Bi ainel 44 [ P.T.O. 91. What 1 07 drift velocity of electrons knowing that in metals, the free electron concentration is about = 1028 electrons/m>? (Take maximum admitted value of the density of electric current for metals as = 107 A/m? and electrical charge of the electron as ‎ = 1. 602 × 10-19 ) (a) 16x10 m/s () 6-24 × 10-22 m/s (c) 161022 m/s (0 6-24 1073 m/s 92. Which one of the following is generated by the supplementary (precession) movements of the conduction electrons that appear when the material is introduced in a magnetic field? (a) Langevin diamagnetism (b) Landau diamagnetism (c) Lorentz diamagnetism (‌) Larmor diamagnetism 93. The cermet of Au/SiO is obtained by () the deposition on glass support and consists in conductive particles of gold speeded in amorphous matrix of SiO, (b) transforming the silicon monoxide at the deposition in a reactive component (Si) and in an insulating one (5102) ( the mixture of a-Cr, Cr3Si and 5107 amorphous () the expansion of both non- conductive and conductive zones of a reactive component (Si) RSPV-T-NLEE/63A 22 + Match the following Lists : List-I 11581 (Class of the (Limiting working material) temperature) ‎ 2 ‎ 0. E 2. 180 10 . : 3. 90 °C 4. 105 °C Select the correct answer using the code given below. : 2 4.41 Re 4.1. . . 1 2 | ౪ ୪୭୦୬ ; ‌ 95. A transformer core is wound with a coil carrying an alternating current at a frequency of 50 Hz. The hysteresis loop has an area of 70000 units, when the axes are drawn in units of 107 Wb-m~? and 102 ^-71-1. What is the hysteresis loss by assuming the magnetization to be uniform throughout the core volume of 0:02 7013? (a) 350 W (b) 700 W ( 3500 W (0 7000 96. L is measured value of inductance with 98. What is the conductivity of copper at magnetic core, Lg is measured value of 300K, if the collision time for inductance without magnetic core, 0 is electron scattering is 2x 10785 8 at magnetic permeability of free space, his this temperature? (Take the number of height of the material under test, c is free electrons per 113 of copper as outer diameter of the material under 85x 1078, electron charge as test, d is inner diameter of the material 1602010156 and mass of free under test. What is the formula for electron as 911071 kg) relative magnetic permeability (u,)? (0 ` 4.8 × 107 L-L tn ‎ + nin(£) (b) 6x107!! ഞ്ഞ്‌ ! -୮ ¬ 1 L-Lo 27 4:8x107!7 011? 1 ‌? (b) ‎ = 8217 a nin(£) (0) 6x107 1-11 ‎ 27 hi (2) 99. Match the following Lists : ‎ 6 List-I 7456-17 (= 770 21 (Material) (Density) d 0 = (2) £. Silver 1. 2.70 ×103 kg-m~ " 97. Consider the following statements 2. 8:96 ×107 kgm regarding ferrites : ... R. Gold 3. 10-49 x 10° kg-m~$ 1. Ferrites are linear materials and present hysteresis cycle. 8. Aluminium 4. 19-32 102 18403 2. The values of saturation induction and remanent induction are lower. ` Select the correct answer using the code 3. Magnetic permeability is lower and given below. more sensitive at the action of external magnetic fields. (a) P Q 5 3 2 1 4 Which of the above statements is/are correct? (0) P Q R 5 4 1 3 2 (a) 1 and 2 ‎ 2.79 - 8 (b) 2 only 8 2 4 1 (c) 3 only ‎ P Q R 8 (d) 2 and 3 4 1 2 3 RSPV-T-NLEE/63A 23 [ P.T.O. 100. The resistivity of pure copper at room temperature is 1-8 x 10 8 ohm-m. The resistivity of Cu-4% Ni alloy at room temperature is 7-0 x 10 8 ohm-m. What 15 the resistivity due to impurity scattering by 1% of nickel in the copper lattice? (0) 2:2210 8 ohm-m (b) 65x10 ohm-m ( 020008 ohm-m (8 13210 8 ohm-m 101. What is the power supplied by each element in the circuit shown below? # = -100 ; ‎ =60W; ‎ = -48 ; P, =-8W (0) ;10077 = ‎ =-60W; ; P, =8W‏ 48- = (© &--100 ; ‎ = -60 W; =48W; P, =-8W‏ =-100W; Py = 60 ‏ 0( ; 2; =-8W‏ 48= RSPV-T-NLEE/63A 24 102. What are V, and i respectively in the circuit shown below? 21, ‏ ۸۸۸۸ 12 ) 6 (a) 5481, -8 ^ ) +24 , -4 +8 A (© -48 , +4 ^ (0) -24 , 103. The electron beam in a TV picture tube carries 1015 electrons per second. What is the voltage 0) needed to accelerate the electron beam to achieve 4 W? (a) 10 kV (b) 15 kV (© 30 kV (9) 25 kV 104. Consider the following statements regarding network theorems : 1. With independent sources, superposition theorem can be used only when the control functions are external to the network containing the sources, so that the controls are unchanged as the sources act one at a time. 2. AQ linear, active, resistive network, which contains one or more voltage or current sources, can be replaced by a single voltage source and a series resistance or by a single current source and parallel resistance. The voltage is called the Thévenin equivalent voltage and the current is Norton current. 3. The two resistances are the same in both Thévenin’s and Norton’s theorems which are obtained by deactivating all the sources. Which of the above statements is/are correct? (a) (b) (0) () 1 only 2 only 1 and 2 2 and 3 105. A 10-ohm resistor has a current of 1 = 2. 5 91101 (). What are the values of voltage and power respectively over one cycle of 0) 500 rad/s? (a) 2581701 (); 62-5sin? wt (W) (b) 25081701 (); 625sin? wt () (c) 2. 5510 © (); 62-5sin? wt (W) (‌) 25917001 (); 625sin? wt (W) RSPV-T-NLEE/63A 25 106. For the network given below, what are the Norton’s current and Thévenin’s voltage at the terminals a and b? & 102 -110 % 32 a 10.0 bb j4Q 10.0" 3-/4 (0 12% = | ˆ | 10; 193 579 |(3, 6‎ 3+ 76 ‎ = 107 જ ସର୍ତ 13+ நி ) 10/0 34 1 ~ # A = = 0209 ‎ 3+ 6‎ and एक = ਟਨ టయోాగ 1040 3- 14 (0 1 = [ Ja 10 + 2103-99 3-6 3- 76 and Vip ‎ 30040) 1040 3474 () Tgp = # [ Ja 10 + (-70( + 3-6 3 - 76 and 17 = ‎ (2.7.0. 107. Consider regarding power the following statements measurement by two-wattmeter method : 1 Two wattmeters connected in any two lines of a three-phase, three- wire system will correctly indicate the total three-phase power by the sum of the two meter readings. A meter will attempt to go downscale if the phase angle between the voltage and current exceeds 180°. In practical case, the balanced load is usually known to be inductive (9 > 0°). Which of the above statements is/are correct? (a) 1 and 2 (b) 1 and 3 ( 2 and 3 () 2 only 108. What are the Zparameters for the network given below? (a) 211 = 6; 212 = 3; 221 = 10; 222 = 5 (0) 2] = 64 ; 10: 221 = 3; 222 = 6 211 = 6; 212 = 10; 221 = 10; 222 =5 (0 211 = 6; 212 = 3; 221 = 3; 222 = 5 RSPV-T-NLEE/63A 26 109. The simplified model of a bipolar junction transistor for small signals is shown in the figure below : 7 Bh 2 28 ` + at 17 V2 What are the h-parameters? and 182 = 0‏ 0 = = 722 = ]‏ () and hy, = 0‏ 0 = = 2 = 122 (b)‏ 0 = and‏ 0 = 122 = = ]‏ 0( and 1122 = 9‏ 0 = = () 1 = hyp‏ 110. Which one of the following statements is not correct regarding mutual inductance and transformers? (a) () (c) (0) When the assumed currents both enter or both leave a pair of coupled coils by the dotted terminals, the signs on the M-terms will be the same as the signs on the L-terms. When one current enters by a dotted terminal while the other leaves by a dotted terminal, the signs on the M-terms will be opposite to the signs on the L-terms. The term ‘close coupling’ is used to describe the case where most of the flux links the coils, either by way of a magnetic core to contain the flux or by interleaving the turns of the coils directly over one another. Coils placed side-by-side without a core are loosely coupled and have correspondingly high values of k. If all the flux links the coil without any leakage flux, then k = 1. On the other extreme, the coil axes may be oriented such that no flux from one can induce a voltage in the other, which results in k = 0. 111. Consider the following statements 113. Match the. following Lists regarding time regarding factors affecting the constant with capacitor discharging capacitance : voltage : li The area of the plates is givently List-I List-It proportional to the charge; the Ti tant) (C hee eionar at larger the plate area, the more (Time constant) (Capaci oa se oad Lal electric charges that can be stored. alesis) 2. The longer the distance between P. It 1. 067% of E the two plates, the stronger the oe produced electric field that will ths 1 tela increase the ability to store Re Sr 3. 135% of E charges. Therefore, the distance i between the two plates is directly S. 4 4. 5% of E proportional to the capacitance. T. 5t 5. 1:87% of E 3. Different insulating materials will have different impacts on the Select the correct answer using the code capacitance. The dielectric given below. constant is directly proportional to the capacitance. (a) P Qee RtoSe ob 1 P 3 4 5 Which of the above statements is/are > &) 2? 9 R Ss T correct 5 2 3 4 1 (a) 2 and 3 (c) P Q R s T (b) 1 and 2 1 3 2 4 5 (c) 1 and 3 (disk g08 Re. 4S oT (ad) 3 only 2 3 4 5 1 112. Which of the following is/are not 114. A single-range laboratory-type potentio- discharging equation/equations for an meter has an 18-step dial switch where R-C circuit? each step represents 0-1 V. The dial resistors are 10 Qeach. The slide wire of nee ay 1. Capacitor voltage v. =Ve FC : ¥ eh Bae the potentiometer is circular and has 2. Resistor voltage vp = Ee" % 11 turns and a resistance of 1Q per V; F turn. The slide wire has 100 divisions 3. Discharging current i= iad and interpolation can be done to one-fourth of a division. What is the Select the correct answer using the code measuring range of the potentiometer? given below. (a) 11V (a) 1 and 2 (o) 2 and 3 (B) O25.N (c) 1 and 3 (eo (d) 1 only (dq) 001 V RSPV-T-NLEE/63A 27 [ Pal. Consider the following statements regarding Maxwell’s bridge : 1. Maxwell’s bridge is limited to measurement of low Q inductors. 2. The final balance equations of Maxwell’s bridge are dependent of frequency. 3. The balance equation of Maxwell’s bridge is dependent of losses associated with the inductor. Which of the above statements is/are correct? (a) 2and3 (b) 2 only (c) 1 only (0) 1 3 116. Match the following Lists : List-I 15 (Name of the (Inductance equation) bridge) £. Maxwell’s 1.71 = நட்ட பம inductance 1+0 bridge 7 Q. Hay’s 20 = [702 + ) + ‎ 144] bridge 73 . Anderson’s 3.71 = 12 --~ bridge Ry S. Owen’s 4. 71 = 22234 bridge Select the correct answer using the code given below. 5‏ 1 .12 555 @ 5‏ 017( 14.13 12‏ S‏ 0 1 2 ‏ 11‏ .‏ 3 RSPV-T-NLEE/63A 28 118. Consider 116 117. The coil of a moving-coil voltmeter is 40 mm long and 30 mm wide, and has 100 turns on it. The control spring exerts a torque of 240x 10-6 N-m when the deflection is 100 divisions on full scale. If the flux density of the magnetic field in the air gap is 1 Wb/m2, what is the resistance that must be put in series with the coil to give one volt per (The resistance of the voltmeter coil may be neglected) division? (0 120×103 (b) 50×103 (0 5103 (0 127103 following statements regarding moving-iron instruments : 1. Moving-iron instruments have their deflection proportional to the square of the current flowing through the coil. 2. Moving-iron instruments have uniform scale marking. 3. Whatever be the polarity of the current in the coil, the deflection of a moving-iron instrument is in the same direction. Which of the above statements is/are correct? (a) 2 and 3 (b) 2 only (c) 1 only (0 1 and 3 120. Consider 119. What is the equation for deflection of the pointer in an electrodynamometer-type instrument when it is operated with AC? 11 dM 6 = 172 ‎ + رم‎ 9-230 ಗಟ್ಟ, ਨ ৫৪১০ ‎ 6 = 12 68 86 _ 10 1 7.2 (a) 8 dt following statements regarding induction-type instruments : 1. 11050, 1.€., if two fluxes are in phase, then the net torque is maximum. If, on the other hand, a = 90°, the net torque is maximum for given values of ), and ` 9 277 - 2, ପଥ 366: torque. 8 ୪୮୭୦) 8 direction as to rotate the disc from the pole with lagging flux towards the pole with leading flux. 3. The expression for torque has a steady value at all times. Which of the above statements is/are correct? (a) 1 and 2 (b) 2 and 3 (0 1 only (0 1800 3 RSPV-T-NLEE/63A 29 * An electrodynamometer-type wattmeter has a current coil with a resistance of 0:1 Qand a pressure coil with resistance of 6:5 1⁄9. What is the percentage error while the meter is connected as current coil to the load side, if the load is specified as 12 A at 250 V with unity power factor? (a) 14:4% 0) 048% (c) 48% (d) 144% „ What is the expression for deflecting torque in single-phase induction-type energy meter? (a) Ty sinBcosa ; = 117127 51710 _ 6 (0) Tg sin(a - 6) 0 (c) Ty = ‎ 2) sina ‎ (0 Ty = 91. sina 0 [ P.T.O. 123. When secondary winding of current transformer is open circuited with primary winding still energized, the large flux greatly increases the 126. Which one of the following code counters is used to remove the ambiguity during the change from one state of the counter to the next during the state transition? (a) flux density in the core and pushes (a) Gray code counter it towards saturation (b) BCD code counter (b) power loss in the winding secondary (c) Excess-3 code counter (ad) Binary code counter (c) leakage flux manifolds 127. Which one of the following gates is most (a) power loss in the primary winding commonly used in the design of a bus system? 124. The purpose of the start bit in digital (a) OR gate voltmeter is to (b) NOT gate (a) hold the digital word in the display (c) XOR gate for a particular time (ad) Buffer gate (b) provide the display of the information that comes from the A/D conversion 128. Consider the following characteristics of CISC architecture : (c) give zero indication on the display during start of conversion 1. A large number of instructions (a) give information about polarity of 2. A large variety of addressing modes the measurand voltage given by the A/D converter 3. Instructions that operands in memory manipulate 4. Fixed-length instruction formats 125. In general, the range of digital multimeter display is Which of the above characteristics are correct? (a) -199 to +199 (a) 1 and 2 only (b) -999 to +999 : (b) 2, 3 and 4 (d) -1999 to +1999 (d) 1,2 and3 RSPV-T-NLEE/63A 30 129. Match the following Lists related to the 131. Which one of the following is not an registers with their functions : operation performed by call subroutine instruction? List-I List-IT (Register name) (Function) (a) The address of the next instruction P. Data Register 1. Holds instruction available in the program counter is (DR) code stored in a temporary location, so the subroutine knows where to Q. Address Register 2. Processor register (AR) return. R. Accumulator (AC) 3. Holds address of instruction (b) Control is transferred to the beginning of the subroutine. S. Instruction 4. Holds memory Register (IR) operand (c) The instruction return from subroutine, transfers the return address from the temporary location into the program counter. T. Program Counter 5. Holds address for (PC) memory Select the correct answer using the code given below. (d) The address of the next instruction available in the program counter is P R Ss T (a) 4 2 2 1 3 stored in an accumulator and returns whenever it is required. (b) P OR Ss uy 5 4 3 1 2, (rr (Saget am S it 3 5 1 2 4 ; staan ; 132. Which of the following lines/diagrams are (iP Q R Ss jh used when the data transfer is between dy Sa Oe ree a an interface and an I/O device? 130. Which one of the following types of instructions is useful for initializing registers to assign a constant value? (a) Strobe lines H : (a) Implied mode instructions rer (b) Direct mode instructions cae F (c) Timing diagrams (c) Immediate mode instructions (d) Indirect mode instructions (d) State diagrams RSPV-T-NLEE/63A 31 [ P.T.O. 133. In which one of the following data 136. The page fault occurs transfer schemes, the CPU stays in a program loop until the I/O unit indicates that it is ready for data (a) when a page currently in a memory transfer while transferring data to and is accessed from peripherals? (a) Programmed I/O (b) when a page currently not in a memory is accessed (b) Interrupt-initiated I/O (c) Direct memory access (c) when an existing page in a memory to replace with a new page is (d) Programmed interrupt I/O accessed 134. Which one of the following methods is (d) when a page from any process in the system for replacement is used to detect burst errors occurring in aes accessed the communication channel? (a) Cyclic redundancy check (b) Bit stuffing . A 137. Suppose that the failures of two drives are (c) Pulse code checking independent; that is, the failure of one is not connected to the failure of the other. (d) Bit spoofing Then, if the mean time between failures of a single drive is 100000 hours and the mean time to repair is 10 hours, the 135. In operating systems, which one of the approximate mean time to data loss ofa following approaches is used to keep mirrored drive system is track of system activities such as the number of system calls made or the number of operations performed to a (a) 17000 years network device or disk? (a) Counters (b) 77000 years (b) Tracing (c) 47000 years (c) Scheduling (a) Pipelining (d) 57000 years RSPV-T-NLEE/63A 32 138. Which one of the following modifiers tells the compiler that a variable’s value may be changed in ways not explicitly specified by the program? (a) Volatile (b) Identifier (c) Const (ad) Typedef Consider the following statements regarding applications of a p-n junction diode : 1. It is used as a switch in DC power supplies. 2. It is used as rectifiers in voltage stabilizing circuits. 3. It is used as signal diodes in communication circuits. Which of the above statements is/are correct? (a) 2 only (b) 2 and 3 (c) 3 only (d) 1 and3 RSPV-T-NLEE/63A 33 140. Consider the following statements regarding transistors : 1. They can be made to oscillate with very small power consumption. 2. They cannot sustain mechanical shocks. 3. Their application is limited up to a few mega-cycles only. Which of the above statements is/are correct? i (a). 2 only (b) 2 and 3 (c) 3 only (d) 1 and 3 141. A field-effect transistor operates with a drain current of 100 mA and a gate source bias of -1V. The device has dynamic forward transconductance value of 0:25S. If the bias voltage decreases to —1:2 V, what is the new value of the drain current? (a) 50 mA (b) 75 mA (c) 150 mA (d) 125 mA [P.T.O. 142. Match the following Lists regarding 144. bipolar junction transistors : List-I List-II (Type of transistor) (Application) P. BC108 (n-p-n) 1. Switching Q. BF180 (n-p-n) 2. General-purpose small-signal amplifier R. 2N3904 (n-p-n) 3. Low-frequency power S. 2N3055 (n-p-n) 4. RF amplifier Select the correct answer using the code given below. dP 0 "RSs 4 oe a fj Pe oO Rees 48s 2a (Po MO er as 3.7 40 neo (dep AO; Gar as De ak ol aes 143. Consider the following statements regarding p-n-p transistor : 1. The base-collector junction is reverse biased to holes in the base region and electrons in the collector region. 2. The base region is very thin and is only lightly doped with electrons. 3. A large proportion of the electrons in the base region cross the base- collector junction into the collector region, creating a collector current. Which of the above statements is/are correct? (a) 2 only (b) 2 and 3 (c) 3 only (d) 1 and 3 RSPV-T-NLEE/63A 34 For a JFET, the typical values of amplification factor and _ transcon- ductance are specified as 80 and 200 nS respectively. What is the dynamic drain resistance of this JFET? (a) 25 kQ (b) 25 po (c) 400 ka (a) 400 pa 145. There is no need of a driver stage, if FET is used as power amplifier instead of BJT, because (a) (b) (c) (a) FET digital circuits need much less power compared to BJT circuits there is no risk of thermal runaway in FET circuits power gain of an FET is much higher than that of a BUT FET is essentially a _voltage- operated device 146. Match the following Lists regarding field- 148. Consider the following statements effect transistor amplifiers : regarding frequency response of BJT amplifiers : List-I 7456-17 (Configuration) (Typical application) 1. The CE amplifier has a high gain P. Common 1. Impedance matching but a relatively narrow bandwidth. source stages . € 610) 10 i Q. Common 2. General-purpose, AF ta ‎ drain and RF amplifiers ‌ £ . Common 3. RF and VHF 3. The CB amplifier has a higher gain gate amplifiers and a larger bandwidth. Select the correct answer using the code | . Which of the above statements is/are aon 7 correct? le = (a) 2 only 3 = (b) 2 and 3 3 2 1 (c) 3 only (0) 9 7 (8) 1 and 2 147. Match the following Lists regarding bipolar transistor amplifiers : 149. In a common-collector amplifier stage, the impedance between base and List-I List-IT ified b { (Configuration) (Typical application) emitter is magnifie 60206 0: Common . and VHF (a) source resistance emitter amplifiers Q. Common 2. Impedance (b) negative feedback collector matching, input and 7 7 output stages (c) Miller effect R. Common 3. General-purpose, AF (0) high-frequency response base and RF amplifiers Select the correct answer using the code given below 150. In Colpitts oscillator circuits, the amount of feedback is controlled by the (a) P Q R ) 8 (a) position of the coil tap (b) ratio of inductances 2 3 2 1 (c) ratio of capacitances ಈ 3 ? స్ట్‌ (d) ratio of resistances RSPV-T-NLEE/63A 35 SPACE FOR ROUGH WORK RSPV-T-NLEE/63A 36 SPACE FOR ROUGH WORK RSPV-T-NLEE/63A 37 (., SPACE FOR ROUGH WORK RSPV-T-NLEE/63A 38 SPACE FOR ROUGH WORK kk × RSPV-T-NLEE/63A 39 26BS—12384 ളി శ لوک‎