OBJECTIVE PAPER-II. Key: (C)

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1 ESE-06 EC Objective Paper-II OBJECTIVE PAPER-II. The closed-loop transfer function of a certain control system is given by C 00 (s). R s 0s 00 Then the settling time for a % tolerance band is given by (A) 0.8 s (B). s (C).5 s (D). s C (s) 00 R s 0s 00 Settling time for % tolerance 4 / 5 t 4 4 / 5 0.8s s. The unit step input response of a certain control system is given by 60t 0t c(t) 0.e.e. The undamped natural frequency n and damping ratio are, respectively (A) 4.5 and.7 (B) 33.5 and.7 (C) 4.5 and.43 (D) 33.5 and.43 The step response c(t) 0.e 60t.e 0t then n and are. c(t) = +0.e 60t.e -0t Impulse response d h(t) c(t) dt dc(t) 60t 0t 0 (0.)( 60)e.( 0)e dt 60 0t h(t) e e Then transfer function 4.49rad / sec n 70 n (4.49) 50 s 0 s 60 s 70s 600 s 70s 600 n In Force-Voltage Analogy (A) Force is analogous to current (B) Mass is analogous to capacitance (C) Velocity is analogous to current (D) Displacement is analogous to magnetic flux linkage In force- voltage analogy Velocity analogous to current 4. For a unity feedback control system having an open-loop transfer function 5 G(s), what is the time t p at which s(s 6) the peak of the step input response occurs? (A) 0.5s (B).75s (C) 0.79s (D).57s 5 G(s) H(s) s(s 6) C.E GH s 6s 5 0 5, 0.6, 4 t p n 0.79sec d 5. The transfer function represents (A) Unstable system (B) Minimum phase system (C) Non-minimum phase system (D) PID controller system d 0(s) G(s) (s0) ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India

2 ESE-06 EC Objective Paper-II 0(s) G(s) (s0) Represents 0 Single right side zero means non-minimum phase 6. What is the maximum input frequency limit of a 3-bit Ripple counter configured around flip-flops, with inherent propagation delay time t pd = 50 ns? (A) 6670 MHz (B) 667 MHz (C) 66.7 MHz (D) 6.67 MHz f clk 9 N.t MHz pd 7. The characteristic equation of a certain feedback control system is given by 4 3 s 4s 3s 36s k 0. The range of values of k for which the feedback system is stable, is given by (A) 0 < k < 4 (B) 4 < k < 36 (C) 0 < k < 36 (D) 3 < k < 36 s 4 +4s 3 +3s +36s+k=0. Then the system is stable for The system is stable, when the first column elements are positive. 36 k k 0 s s s 0 k s 0 0 s 0 3 k k 0 36 k 8. The closed-loop transfer function of a unity feedback control system is, 4 k 0 0 C(s) R(s) s s n n n The velocity error constant of the system is n (A) (B) n n 3n (C) (D) C(s) R(s) s s n n n n G(s) s(s ) The velocity error constant k limsg(s) v v s0 n n lim s0 (s ) k n n n 9. The system described by the following state equations 0 0 X X u, Y [,]X 3 is. Completely controllable. Completely observable Which of the above statements is/are correct? (A) only (B) only (C) Both and (D) Neither nor 0 0 X X U 3 Y [, ] x Q c B AB c AB Qc 3 3 Det Q 0 Controllable 0 CA [ ] 3. n ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India

3 ESE-06 EC Objective Paper-II 0 [ ] Q0 det Q 4 0 Observable k(s ) 0. Consider the system with G(s) s s 3 and H(s) =. The breakaway point(s) of the root loci is/are at (A) 0.65 only (B) only (C) and 0.65 (D) There is no breakaway point k(s ) G(s) s s 3 The Breakaway point of the system is k(s ) s s 3 s, j (s s 3) k s dk ds (s ) (s )(s ) s s 3 dk ds (s ) s s 4s 4 s s 3 s 4s k ' 0 (s ) 5 0 Break points s +4s+=0 s = 0.6 s= 3.73 s = 0.6 is not on root locus therefore it is not valid j j s = 3.73 is break in point where the Root locus branches are coming from complex plane to real axis. Therefore there are no break away points in the system.. How would a binary number 000 be represented by a 4-bit binary word, if the range of voltage is 0 to 0 V? (A) V (B).333 V (C) V (D).000 V Full scale voltage =0 V Full Scale output 0 0 Resolution n 4 5 Voltage for binary number (000) =.333V 3. For a unity feedback system with open-loop 5 transfer function, the resonant peak s(s 6) output M m and the corresponding resonant frequency m, are respectively (A).6 and.64 rad/sec (B).04 and.64 rad/sec (C).6 and 4.8 rad/sec (D).04 and 4.8 rad/sec 5 G(s) s(s 6) C(s) 5 R(s) s 6s 5 5 n 6 n Mm (0.6) (0.6) 0.64 ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 3

4 ESE-06 EC Objective Paper-II m n 5 (0.6).645 rad / sec 3. The transfer function of a control system is said to be All Pass System, if it has (A) Unit magnitude at all frequencies with anti-symmetric pole-zero pattern (B) Unit magnitude at all frequencies with symmetric pole-zero pattern (C) Magnitude varying with frequency and with anti-symmetric pole-zero pattern (D) Unit magnitude at some frequencies with symmetric pole-zero pattern 6. Consider the transfer function: G(s) 5 s 0s 00 s (s 5s) The corner frequencies in Bode s plot for this transfer function are as (A) 0 rad/sec and 0 rad/sec (B) 00 rad/sec and 0 rad/sec (C) 0 rad/sec and rad/sec (D) 00 rad/sec and rad/sec G(s) 5 s 0s 00 s (s 5s) The corner frequencies of Bode plot n = 0, 0 rad/sec, rad/sec Pole zero pattern is anti-symmetric about imaginary axis. 4. Consider the following:. Bode plot. Nyquist plot 3. Nichols chart Which of the above frequency response plots are commonly employed in the analysis of control systems? (A) and only (B) and 3 only (C) and 3 only (D), and 3 5. An A-to-D converter in which one subcircuit is a D-to-A converter is (A) Parallel A/D converter (B) Dual slope A/D converter (C) Successive approximation A/D converter (D) Extended parallel type A/D converter 7. Consider the transfer function ( s) for a PD controller. What is the frequency at which the magnitude is 0 db (by using asymptotic Bode s plot)? (A) 000 r/s (B) 000 r/s (C) 00 r/s (D) 00 r/s G(s) = (0.+0.0s) The frequency at which the magnitude is 0dB G(s) = 0. [+0.s] Asymptotic magnitude M asy = 0log [0.] + 0log [0. ] = 0 0log[0. ] rad / sec 8. The main objectives of drawing the root locus plot are. To obtain a clear picture of the open-loop poles and zeros of the system. To obtain a clear picture of the transient response of the system for varying gain, K ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 4

5 ESE-06 EC Objective Paper-II 3. To find the range of K to make the system stable Which of the above statements are correct? (A), and 3 (B) and only (C) and 3 only (D) and 3 only Root locus main objectives. The open-loop poles zeros location is known with simple s-plane. The Root locus will give clear picture of closed loop-poles movement.. To obtain clear picture of transient response of the system with gain K. 3. To find the range of K to make the system stable. 9. A unity feedback system has open-lop poles at s = j, s = and s = 0 and a zero at s = 3. What are the angles made by the rootloci asymptotes with the real axis? (A) 60, 80 o and 60 o (B) 30 o, 90 o and 60 o (C) 60 o, 0 o and 30 o (D) 30 o, 60 o and 80 o s = j s = s = 0 are poles of the system s = 3 is zero of the system. The asymptotes are p =4 number of poles z = number of zeros p z = 3 o (q)80, q 0,,... p z p z Asymptotes are = 60, 80, The open-loop transfer function of a unity K feedback system is G(s). The gain s(s 5) K that results in a phase margin of 45 o is (A) 35 (B) 30 (C) 5 (D) 0 The K value such that phase margin is = 45 Phase margin pm 80 ( ) 45 o pm sys gc ( ) 35 pm gc o sys ( ) 90 tan o gc sys ( gc) 90 tan gc Magnitude gc o gc o 5 5 o gc o 90 tan K M 5 K M( gc) 5 K From the Nichols chart, one can determine the following quantities pertaining to a closed-loop system: (A) Magnitude, bandwidth and phase (B) Bandwidth and phase only (C) Magnitude and phase only (D) Bandwidth only Nichols chart is used for finding the magnitude, phase and BW. In position control systems, the Tachogenerator feedback is used to (A) Increase the effective damping in the system (B) Decrease the effective damping in the system (C) Decrease the Steady state error (D) Increase the steady state error ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 5

6 ESE-06 EC Objective Paper-II Tacho-generator feedback is example for D controller. Derivative controller reduces ripples in the response i.e., maximum peak over shoot reduces. effective damping increases 3. Consider the following statements:. The pin diode consists of two narrow, but highly doped, semiconductor regions separated by a thicker, lightly doped material called the intrinsic region.. Silicon is used most often for its power handling capability and because it provides a highly resistive intrinsic region. 3. The pin diode acts as an ordinary diode at frequencies above 00 MHz. Which of the above statements are correct? (A) and only (B) and 3 only (C) and 3 only (D), and 3 The pin diode acts as an ordinary diode at frequencies up to about 00MHz, but above this frequency the operational characteristics changes and begins acting as a variable resistance. 4. Consider the following statements:. Additional cavities serve to velocity modulate the electron beam and produce an increase in the energy available at the output.. The addition of intermediate cavities between the input and output cavities of the basic klystron greatly improves the amplification, power output, and efficiency of the klystron. Which of the above statements is/are correct? (A) only (B) only (C) Both and (D) neither nor 5. In a waveguide with perfectly conducting flat wall, the angle of reflection is equal to the angle of (A) Diffraction (B) Incidence (C) Refraction (D) Penetration In a waveguide with perfectly conducting flat wall, the angle of reflection is equal to the angle of incidence. 6. In microwave system, waveguides have the advantages of (A) High power-handling capability and low loss (B) Thin dielectric substrate (C) Low power-handling and adequate stability (D) Positive phase shift 7. A straight dipole radiator fed in the centre will produce maximum radiation at. The plane parallel to its axis. The plane normal to its axis 3. Extreme ends Which of the above statements is/are correct? (A) only (B) only (C) and 3 only (D) and 3 only 8. In communication systems, modulation is the process of (A) Improving frequency stability of transmitter (B) Combining message signal and radio frequency waves ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 6

7 ESE-06 EC Objective Paper-II (C) Generating constant frequency radio waves (D) Reducing distortion in RF waves Modulation is a process of changing the characteristic of carrier signal (radio frequency) with respect to message signal. 9. Which one of the following statements is correct? (A) Sampling and quantization operate in amplitude domain (B) Sampling and quantization operate in time domain. (C) Sampling operates in time domain and quantization operates in amplitude domain. (D) Sampling operates in amplitude domain and quantization operates in time domain. Sampling discretize the time axis. Quantization discretize the amplitude axis. 30. What is the voltage attenuation provided by a 5 cm length of waveguide having a = cm and b = 0.5 cm in which a GHz signal is propagated in the dominant mode? (A) 7 db (B) 68 db (C) 5 db (D) 48 db Given a = cm; b = 0.5cm l c 5cm 5 0 m a cm 0 m Attenuation db 68.5dB 3. When a plane wave travelling in free-space is incident normally on a medium having C r = 9.0 and r =.0, the fraction of power transmitted into the medium is (A) 4 3 (B) 3 4 (C) 3 3 Fraction of transmitted power (D) 3 3. A microwave antenna with the absorbing cross-section area (A) and the power flux density (S) in the incident wave is employed as an absorber. The absorbed power (P) of the antenna is (A) A (B) S (C) SA (D) S S A A 33. LASER beam of light essentially finds its application in transmission of a signal in the optical fiber communication systems due to (A) Incredible speed of signal communication (B) Low loss transmission of the signal (C) Inexpensive installation cost (D) Bulk availability of LASER sources Key: (A & B) 34. The controller which is highly sensitive to noise is (A) PI (B) PD (C) Both PI and PD (D) Neither PI nor PD PD controller is very sensitive to noise 35. The s complement representation of 7 is (A) 0000 (B) 0 (C) 00 (D) 00 ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 7

8 ESE-06 EC Objective Paper-II 7 = s comp of (+7) = ( st complement +) = s comp of (0000) = The subtraction of two hexadecimal numbers 84 6 A 6 results in (A) B 6 (B) 3A 6 (C) 4B 6 (D) 5A A 6 = 5A 6 (84) (3) 6 0 (A) (4) 6 0 (5A) (90) The Vestigial Side Band (VSB) modulation is preferred in TV systems because. It reduces the bandwidth requirement to half. It avoids phase distortion at low frequencies Which of the above statements is/are correct? (A) only (B) only (C) Both and (D) Neither nor Bandwidth in VSB is.5b, where B is message signal bandwidth. Phase distortion are reduced at low frequency. 38. If, A = 60 and B = 3, then using C- programming A >> B results in (A) (B) (C) 00 (D) 0000 We have to do the right shifting of binary equivalent of 60by 3 bit positions. 0000>> What is the base of the numbers for the following operation to be correct? (54) (4) ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India b b (3) b (A) (B) 4 (C) 8 (D) 6 54b 3b 4 b (5b 4) (b 3)4 5b 4 4b b It is awkward to employ signed-magnitude system in computer arithmetic, because. Sign and magnitude have to be handled separately. It has two representations for 0 Which of the above statements is/are correct? (A) only (B) only (C) Both and (D) Neither nor Statement is correct. The signed magnitude system is used in ordinary arithmetic but is awkward when employed in computer arithmetic. Therefore, the signed complement is normally used. The s complement imposes difficulties because it has representations of 0 (+0 to -0) 4. A single-stage amplifier has a voltage gain of 00. The load connected to the collector is 500 and its input impedance is k. Two such stages are connected in cascade through an R-C coupling. The overall gain is (A) 0000 (B) (C) 5000 (D) IN V Rin gmv Rout R V in gmv STAGE I STAGE II 8 Rout OUT

9 ESE-06 EC Objective Paper-II R k, R 500 IN g R m OUT OUT 00(Given) 00 gm 0.s 500 Overall gain g R R.g R m OUT IN m OUT Assuming V CE(Sat) = 0.3V for a Silicon transistor at ambient temperature of 5C and h FE = 50, the minimum base current I B required to drive the transistor into saturation for the circuit shown is 5V I B (A) 64 A (B) 78 A (C) 94 A (D) 40 A Step: () KVL for output section of the circuit 5V VCE 5V 0.3V sat Ic 4.7mA sat k k ICsat Q k 5V k Step: () Minimum Base current required to drive the BJT into saturation, I Bmin IC I sat C 4.7mA sat IBmin 94A h 50 FE 43. Which of the following regions of operation are mainly responsible for heating of the transistor under switching operation?. Saturation region. Cut-off region 3. Transition from saturation to cut-off 4. Transition from cut-off to saturation Select the correct answer using the codes given below (A),, and 4 only (B), 3, and 4 only (C) and 3 only (D) and 3 only The heating of a transistor under switching operation occurs during Transition from saturation to cut-off Transition from cut-off to saturation Saturation region 44. In a sinusoidal oscillator, sustained oscillations will be produced only if the loop gain (at the oscillation frequency) is (A) Less than unity but not zero (B) zero (C) Unity (D) Greater than unity The condition for sustained oscillation in a sinusoidal oscillator at a particular frequency is A v = Loop gain = (Bark hausen criteria) I B Q V CE sat 45. The Class-B push-pull amplifier is an efficient two-transistor circuit, in which the two transistors operate in the following way: ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 9

10 ESE-06 EC Objective Paper-II (A) Both transistors operate in the active region throughout the negative ac cycle (B) Both transistors operate in the active region for more than half-cycle but less than a whole cycle (C) One transistor conducts during the positive half-cycle and the other during the negative half-cycle (D) Full supply voltage appears across each of the transistors In a class-b push-pull amplifier, the conduction angle of each transistor is 80 o (i.e.) Each transistor is biased to conduct for ONE-HALF CYCLE OF INPUT SIGNAL only. In other words, During +Ve half cycle of input signal, One transistor (Let Q ) is pulled into ON state and the other transistor (Let Q ) is pushed into OFF state. During Ve half-cycle of input, Q is pulled into ON state and Q is pushed into OFF state. 46. Consider the following statements regarding Wien Bridge oscillator:. It has a larger bandwidth than the phase shift oscillator.. It has a smaller bandwidth than the phase shift oscillator. 3. It has capacitors while the phase shift oscillator has 3 capacitors. 4. It has 3 capacitors while the phase shift oscillator has capacitors. Which of the above statements are correct? (A) and 3 only (B) and 4 only (C) and 4 only (D) and 3 only RC Phase shift Oscillator Suitable for oscillations in Audio frequency (AF) range, preferably upto khz. Three identical RC sections are to be used in the phase shift network to construct a practical RC Phase shift oscillator. Wien Bridge Oscillator Suitable for Oscillations in AF range up to 00kHz. Two RC sections (One series RC & one parallel RC) are used in the feedback network 47. For normal operation of a transistor (A) Forward bias the emitter diode and reverse bias the collector diode (B) Forward bias the emitter diode as well as the collector diode (C) Reverse bias the emitter diode as well as the collector diode (D) Reverse bias the emitter diode and forward bias the collector diode Normal operation of a transistor is ACTIVE REGION of operation Emitter Diode/ Emitter junction, J E Collector Diode/ Collector junction Region of operation R.B R.B Cut-off Region F.B F.B Saturation Region F.B R.B Normal active region R.B F.B Inverse (or) Reverse Active Region 48. Consider the following statements regarding linear power supply:. It requires low frequency transformer.. It requires high frequency transformer. ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 0

11 ESE-06 EC Objective Paper-II 3. The transistor works in active region. Which of the above statements is/are correct? (A) only (B) and 3 only (C) and 3 only (D) 3 only The Requirements of Linear Power supply:. As the input signal or line voltage frequency is very low, to handle this, a low frequency transformer is required.. As the transistor is a control element in linear voltage regulator, it must be operated in active region, so that the load current (or Emitter current) is controlled as per the requirements. 49. The capacitance of a full wave rectifier, with 60Hz input signal, peak output voltage V p = 0V, load resistance R =0 k and input ripple voltage V r = 0.V, is (A).7 F (B) 33.3 F (C) 4.7 F (D) 83.4 F The general formula for ripple voltage V ripple in FWR with capacitor filter is Vp V ripple ; fcr Vp C frv ripple 0V 4.66F 3 60Hz 00 0.V 50. A full wave rectifier connected to the output terminals of the mains transformer produces an RMS voltage of 8 V across the secondary. The no-load voltage across the secondary of the transformer is (A).6V (B) 6.V (C) 6.V (D) 6.V Note: The question should have been The no-load DC voltage across the output of the rectifier is Full wave rectifier Step() : V m rms Vm 8V V 8V V Step() : No V m load voltage VDC V 6.39V 5. An op-amp can be connected to provide. Voltage controlled current source. Current controlled voltage source 3. Current controlled current source Which of the above statements are correct? (A) and only (B) and 3 only (C) and 3 only (D), and 3 An Op-amp can be connected to provide. Voltage controlled voltage source (VCVS), whose output voltage V 0 is controlled by the input voltage Vi. Current controlled current source (CCCS), whose output current I 0 is controlled by the input current I i 3. Voltage controlled current source (VCCS), whose output current I 0 is controlled by the input voltage V i. 4. Current controlled voltage source (CCVS), whose output voltage V 0 is controlled by the input current I i. 5. In an Op-Amp, if the feedback voltage is reduced by connecting a voltage divider at the output, which of the following will happen?. Input impedance increases. Output impedance reduces 3. Overall gain increases Which of the above statements is/are correct? (A) only (B) only (C) 3 only (D), and 3 ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India

12 ESE-06 EC Objective Paper-II If Feedback factor () is reduced Vf V A CL INCL OUTCL o A Increases A R R ( A ) Decreases R IN R OUT Increases A 53. The transient response rise time (unity gain) of an Op-Amp is 0.05 s. The small signal bandwidth is (A) 7 khz (B) 0 khz (C) 7 MHz (D) 0 MHz Rise time of an op-amp, t r = 0.05sec Small-signal band width can be related to t r using the relation 0.35 tr BW BW 7MHz 6 t r 54. A negative feedback of = is applied to an amplifier of open-loop gain 000. What is the change in overall gain of the feedback amplifier, if the gain of the internal amplifier is reduced by 0%? (A) 95.7 (B) 86.7 (C) 75.7 (D) A 000, Step () A 000 Af A Step: () Gain of internal amplifier is reduced by 0% 0% of i.e., A New Af New If the quality factor of a single-stage single tuned amplifier is doubled, the bandwidth will (A) Remain the same (B) Become half (C) Become double (D) Become four times Quality factor Q BW If Q is doubled Bandwidth will become half 56. Consider the following statements related to oscillator circuits:. The tank circuit of a Hartley oscillator is make up of a tapped capacitor and a common inductor.. The tank circuit of a Colpitts oscillator is made up of a tapped capacitor and a common inductor. 3. The Wien Bridge oscillator is essentially a two-stage amplifier with an RC bridge in the first stage, and, the second stage serving as an inverter. 4. Crystal oscillators are fixed frequency oscillators with a high Q-factor. Which of the above statements are correct? (A), and 3 only (B), 3 and 4 only (C), and 4 only (D), 3 and 4 only Hartely Oscillator used as a tapped inductor 57. The most commonly used transistor configuration for use as a switching devices is (A) Common-base configuration (B) Common-collector configuration (C) Collector-emitter shorted configuration (D) Common-emitter configuration f 0 ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India

13 ESE-06 EC Objective Paper-II CB configuration. Current amplifier. Used as current Buffer 3. Current controlled current source CC configuration. Voltage amplifier. Used as voltage Buffer 3. Voltage controlled voltage source CE configuration General purpose configuration used in. Amplifier circuits. Switching circuits 58. The value of h FE (the hybrid parameters) of a Common-Emitter (CE) connection of a Bipolar Junction Transistor (BJT) is given as 50. What is the value of dc (ratio of collector current to emitter current), for this BJT? (A) (B) (C) (D) The current amplification factor of a BJT in CE configuration IC hfe 50 I B I 50 C DC IE For realizing a binary half-subtractor having two inputs A and B, the correct set of logical expressions for the outputs D (A minus B) and X(borrow) are. The difference output D AB AB. The borrow output B AB Which of the above statements is/are correct? (A) only (B) only (C) Both and (D) Neither nor D Difference AB AB B Borrow AB 60. The simplified form of the Boolean expression AB + A(B + C) + B(B + C) is given by (A) AB + AC (B) B + AC (C) BC + AC (D) AB + C F = AB +AB + AC +B +BC = B (A + A + + C) +AC A = B + AC 6. Consider the following statements: Pointers in C-programming are useful to. Handle the data tables efficiently. Reduce the length of a program 3. Reduce the complexity of a program Which of the above statements are correct? (A) and only (B), and 3 (C) and 3 only (D) and 3 only With the help of pointer concept only. We can pass all the elements of the array just by passing the base address. 6. Data transfer between the main memory and the CPU register takes place through two registers, namely, (A) General purpose register and MDR (B) Accumulator and Program counter (C) MAR and MDR (D) MAR and Accumulator MAR Memory Address Register The MAR holds the address of the location to be accessed. MDR Memory Data Register The MDR contains the data to be written into or read out of the addressed location. ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 3

14 ESE-06 EC Objective Paper-II 63. In a binary tree, the number of internal nodes of degree is 3, and the number of internal nodes of degree is 6. The number of leaf nodes in the binary tree is (A) 7 (B) 8 (C) 9 (D) 0 I = 3, I = 6, E = 5 node = 6 Number of edges = () 6 + () 3 = 5 nodes = 5 + = 6 L L I I I I I I I The number of leaf nodes s = 6 (6+3) = Consider the following:. Operation code. Source operand reference 3. Result operand reference 4. Next instruction reference Which of the above are typical elements of machine instructions? (A), and 3 only (B), and 4 only (C) 3 and 4 only (D),, 3 and 4 Typical elements of machine instructions are. Operation code (Op-code). Source operand reference 3. Result operand reference 65. Which addressing mode helps to access table data in memory efficiently? I L3 L 4 L5 L6 I L 7 (A) Indirect mode (B) Immediate mode (C) Auto-increment or Auto-decrement mode (D) Index mode Index addressing mode helps to access table data in memory efficiently 66. Converting an analog signal to digital signal is done by Sampling and (A) Companding (B) Mixing (C) Quantizing (D) Pre-emphasis Total Data rate = N.r b N = number of users r b = Bit rate Total data rate 43kbps kbps Bit duration = 3 0 For one frame 4 bits are included. Thus time duration for one frame= msec A computer employs RAM chips of 56 bytes and ROM chips of 04 bytes. If the computer system needs kb of RAM and kb of ROM, then how many address lines are required to access the memory? (A) 0 (B) (C) (D) 3 As per question, computer system needs kb of RAM and kb ROM which means that computer system needs kb, (RAM size+ ROM size) of total memory. kb lines =. Hence option B is correct answer. 0. B. B so, number of address 68. A computer system has a cache with access time 0 ns, a hit ratio of 80% and average ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 4

15 ESE-06 EC Objective Paper-II memory access time is 0 ns. Then what is the access time for physical memory? (A) 50 ns (B) 40 ns (C) 30 ns (D) 0 ns Given data T 0ns, H 80% C T 0ns, T? avg M T H T H T T avg C C M 0 (0.8)(0) (0.) 0 T (0.)TM T T M 0 0.TM 0 TM 50ns In synchronous TDM, there are four inputs and data rate of each input connection is 3 kbps. If bit at a time is multiplexed, what is the duration of each frame? (A) 0.0 ms (B) 0.03 ms (C) 0.33 ms (D) 0. ms Synchronous TDM, No. of Inputs = N = 4 Data rate of each input connection = 3 kbps = n f s Data rate of TDM system (in the channel) = N.n f s = 4 3k r b = kbps Each bit duration = T b r k sec b M M bit at a time is multiplexed. Collection of each sample from all signals constitutes a frame. Since bit at a time is multiplexing one frame contains 4 bits. Input signals are4 Frame duration 4bits duration 4T b msec k 70. Consider the following statements comparing Static RAM with Dynamic RAM:. In Static RAM typical cell requires more number of transistors than the Dynamic RAM.. Power consumption per bit of Static RAM is less than that of Dynamic RAM. 3. Dynamic RAM is less expensive than the Static RAM. Which of the above statements are CORRECT? (A), and 3 (B) and only (C) and 3 only (D) and 3 only In Static RAM typical cell requires more number of transistors than the Dynamic RAM. Dynamic RAM is less expensive than the Static RAM. SRAM Consumes more power. m t r b m m3 m4 t t t r b r b r b 3k decommutator channel 7. An addressing mode in which the location of the data is contained within the mnemonic, is known as (A) Immediate addressing mode (B) Implied addressing mode (C) Register addressing mode (D) Direct addressing mode ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 5

16 ESE-06 EC Objective Paper-II An addressing mode in which the location of the data is contained within the mnemonic, is known as Direct addressing mode. 7. A processor has 3-bit architecture. Each instruction is word long (3 bits). It has 64 registers. It supports 50 instructions, which have register operands + immediate operand. Assuming that the immediate operand is an unsigned integer, what is its maximum value? (A) 6383 (B) 3767 (C) (D) 04 3 bit Opcode Rs Rd Operand log 50 log 64 log With 4 bit, the Highest unsigned integer is Microwave resonators are used in. Microwave oscillators. Microwave narrow band amplifiers 3. Microwave frequency meters Which of the above are correct? (A) and only (B) and 3 only (C) and 3 only (D), and The serial connection of interrupt lines for establishing hardware priority is known as (A) Daisy Chaining Priority (B) Parallel Priority (C) Polling (D) Serial-line Priority The Daisy Chaining method of establishing priority consists of a serial connection of all devices that request an interrupt. The device with the highest priority is placed in the first position, followed by lower priority devices upto the device with the lowest priority, which is placed last in the chain. Directions: Each of the next six (6) items consist of two statements, one labeled as the Statement (I) and the other as Statement (II). Examine these two statements carefully and select the answer to these items using the codes given below: Codes: (A) Both statement (I) and statement (II) are individually true and statement (II) is the correct explanation of statement (I). (B) Both statement (I) and statement (II) are individually true and statement (II) is not the correct explanation of statement (I) (C) Statement (I) is true but Statement (II) is false. (D) Statement (I) is false but statement (II) is true 75. Statement (I): PAM can be demodulated using a suitable integrator. Statement (II): A suitable integrator practically acts as can an envelop detector. 76. Statement (I): The direction flag D in 8086 selects increment or decrement mode for DI and/or SI registers. Statement (II): If D = 0, the register are automatically decremented. 77. Statement (I): An antenna of length will have radiation patterns of two lobes. ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 6

17 ESE-06 EC Objective Paper-II Statement (II): An antenna of length 3 will have radiation pattern of two lobes and two minor lobes. n cos null H () H 4 Cos 4n null For n 0 Cos null null 0, z null 3 3 () H 4 4n Cosnull 3 For n=0 cos null null 0, For n cosnull 3 null cos null, ,09.4 z null Radiation pattern Radiation pattern 78. Statement (I): The complex conjugate poles and zeros of the open-loop transfer function have no effect on the root-loci on the real axis. Statement (II): Angle contribution of such a pair of conjugate poles or zeros is radians on the real axis 79. Statement (I): A basic memory unit of a flip-flop is a bistable multivibrator. Statement (II): A flip-flop has two stable states. It remains in one state until it is directed by an input signal to switch over. 80. Statement (I): Multimode fibers are now used for long distance communication. Statement (II): Multimode fibers have larger core-radius than single-mode fibers. 8. Product of Max terms representation for the Boolean function F BD AD BD is (A) M(,3,5,7) (B) M(0,,4,6) (C) M(0,,,3) (D) M(4,5,6,7) Convert SOP to POS form F(A,B,D) BD AD BD BD A A AD B B BD A A ABD ABD ABD ABD ABD ABD m(,3,5, 7) F M(0,,4,6) 8. Simplified form of the Boolean expression Y A.B CA B C is (A) AC AC BC BC (B) A B CA B C ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 7

18 (C) A BA C (D) A(B C) Y A.B CA B C AB CA.B C AA 0, A B A.B ABC ABC ABC.A.B.C A B CA B C 83. What is the maximum frequency for a sine wave output voltage of 0V peak with an Op-Amp whose slew rate is V/s? (A) 5.9 khz (B) 9.73 khz (C) 3.54 khz (D) 7.36 khz Slew rate of op-amp = V/sec =0 6 V/sec & V m = 0V We have slew rate = V m.fm The maximum frequency upto which the op-amp can provide undistorted output, f max 6 slew rate kHz V 0V m 84. Which one of the following statements is correct? (A) TTL logic cannot be used un digital circuits (B) Digital circuits are linear circuits (C) AND gate is a logic circuit whose output is equal to its highest input. (D) In a four-input AND circuits, all inputs must be high for the output to be high. 85. The Slew rate is the rate of change of output voltage of an operational amplifier when a particular input is applied. What is that input? ESE-06 EC Objective Paper-II (A) Sine wave input (B) Ramp input (C) Pulse input (D) Step input Slew rate is defined as the maximum rate of change in the output voltage of an op-amp caused by step input voltage Slew rate () V i V 0 V i Slope slew rate V 0 V Except at high frequencies of switching, nearly all the power dissipated in the switch mode operation of a BJT occurs, when the transistor is in the (A) Active region (B) Blocking state (C) Hard saturation region (D) Soft saturation region t t V 0 t ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 8

19 ESE-06 EC Objective Paper-II Switches are designed to operate in either cut-off or hard-saturation. No power dissipation in cut-off. 87. Consider the following statements with respect to combinational circuit:. The output at any time depends only on the present combination of inputs.. It does not employ storage elements 3. It performs an operation that can be specified logically by a set of Boolean functions. Which of the above statements are correct? (A) and only (B) and 3 only (C) and 3 only (D), and Consider the following statements: A multiplexer. selects one of the several inputs and transmit it to a single output.. routes the data from a single input to one of many outputs. 3. converts parallel data into serial data 4. is a combinational circuit Which of the above statements are correct? (A) and 3 only (B) and 4 only (C), 3 and 4 only (D),3 and 4 only 89. What are the two types of basic adder circuits? (A) Half adder and full adder (B) Half adder and parallel adder (C) Asynchronous adder and synchronous adder (D) One s complement adder and two s complement adder 90. Consider the following statements:. An 8-input MUX can be used to implement any 4 variable functions.. A 3-line to 8-line DEMUX can be used to implement any 4 variable functions. 3. A 64-input MUX can be built using nine 8-input MUXs. 4. A 6-line to 64-line DEMUX can be built using nine 3-line to 8-line DEMUXs. Which of the above statements are correct? (A),, 3 and 4 (B), and 4 only (C)3 and 4 only (D), and 3 only 9. For an n-bit binary adder, what is the number of gates through which a carry has to propagate input to output? (A) n (B) n (C) n (D) n+ 9. The main disadvantage of DTL logic circuits is (A) Medium speed (B) Very large power supply voltage (C) High cost (D) Very large gate propagation delay. 93. Which one of the following statements best describes the operation of a negative-edge triggered D flip-flop? (A) The logic level at the D input is transferred to Q on NGT of CLK (B) The Q output is always identical to the CLK input if the D input is high (C) The Q output is always identical to the D input when CLK = PGT (D) The Q output is always identical to the D input. 94. A 3-bit ripple counter is constructed using three T flip-flops to do the binary counting. The three flip-flops have T-inputs fixed at ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 9

20 ESE-06 EC Objective Paper-II (A) 0, 0 and (B), 0 and (C) 0, and (D), and In ripple counter, whether up-counter or down counter all T-flip flop are operated in toggle mode. 95. What is the function Y A BC in Product-of Sums (POS) form? (A) M6M5M4M 3 (B) M3MMM 0 (C) M0MM 3 (D) M4M3MM Convert SOP to POS form Y ABC A B B C C BC A A ABC ABC ABC ABC ABC ABC M(0,,3) 96. The initial content of a four-bit shift register is 000. What is the register content after it is shifted four times to the right, with the serial input being 00? (A) (B) 00 (C) 000 (D) 00 Clk Serial I P Q3 Q Q Q When a large number of analog signals is to be converted to digital form, an analog multiplexer is used. The A-to-D converter most suitable in this case will be (A) Forward counter type (B) Up-down counter type (C) Successive approximation type (D) Dual slope type 98. For Emitter-coupled logic (ECL), the switching speed is very high because (A) Negative logic is used (B) The transistors are not saturated when they are conducting (C) Multi-emitter transistors are used (D) Of low fan-out 99. A flip-flop is a (A) Combinational logic circuit and edge sensitive (B) Sequential logic circuit and edge sensitive (C) Combinational logic circuit and level sensitive (D) Sequential logic circuit and level sensitive 00. The transfer function will have s (A) dc gain and high frequency gain (B) dc gain 0 and high frequency gain (C) dc gain and high frequency gain 0 (D) dc gain 0 and high frequency gain G(s) s M ( ) 0 M M 0 0. Consider the following statements: The Gain margin and phase margin of an unstable minimum phase system may respectively be ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 0

21 ESE-06 EC Objective Paper-II. Positive, negative. Negative, positive 3. Negative, negative Which of the statements is/are correct? (A) 3 only (B) and only (C) and 3 only (D), and 3 Gain margin and phase margin for unstable system GM vedb db PM(deg rees) ve 0. A phase lead compensator has its transfer 0.5s function, G c(s). The maximum 0.05s phase lead and the corresponding frequency, respectively are nearly (A) sin (0.9) and 6r/s (B) sin (0.8) and 4 r/s (C) sin (0.9) and 4 r/s (D) sin (0.8) and 6 r/s 0.5s G(s) 0.5s s 0.5s s 0.05s m 6.3rad / s m sin sin [0.8] 03. Consider the following statements:. Lead compensation decreases the bandwidth of the system.. Lag compensation increases the bandwidth of the system Which of the above statement is/are correct? (A) only (B) only (C) Both and (D) Neither nor Lead compensator, Bandwidth increases Lag compensator, Bandwidth decreases 04. A proportional controller with transfer function, K P is used with a first-order system having its transfer function as K G(s), in unity feedback structure. ( s ) For step inputs, an increase in K P will (A) Increase the time constant and decrease the steady state error (B) Decrease the time constant of CLTF and decrease the steady state error (C) Decrease the time constant of CLTF and increase the steady state error (D) Increase the time constant and increase the steady state error kk p OLTF ( s ) RS OLTF p ss p k limoltf k k e k s0 ss p CLTF p k k e kk p CLTF s k k k k k CLTF p k p p p Gs k k p Cs ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India

22 ESE-06 EC Objective Paper-II 05. For a second-order differential equation, if the damping ratio is unity, then (A) Then poles are imaginary and complex conjugate (B) The poles are in the right half of s-plane (C) The poles are equal, negative and real (D) Both the poles are unequal, negative and real, C R s s n n n n The poles are equal, real and Ve 06. Consider the following statements associated with micro strip patch antenna:. The micro strip patch behaves more like a leaky cavity rather than like a radiator and this is not a highly efficient antenna.. They can be adapted for radiation of circularly polarized waves. Which of the above statement is/true correct? (A) only (B) only (C) Both and (D) Neither nor 07. A carrier waveform 0 cos c t and modulating signal 3 cos m t have f c = 00kHz and f m = 4kHz. Given that sensitivity of FM is 4 khz/v and FM spectra beyond J 6 is negligible, what are the channel bandwidth requirements for AM and FM, respectively? (A) khz and 48 khz (B) 8 khz and 48 khz (C) khz and 54 khz (D) 8 khz and 4 khz AM Bandwidth B 4kHz 8kHz ( B is message signal bandwidth) For FM Total frequency spread is from fc 6fm to fc 6fm Total Bandwidth f m 4 48kHz 08. When the modulating frequency is doubled, the modulation index is halved, and the modulating voltage remains constant. The modulation system is. Amplitude modulation. Phase modulation 3. Frequency modulation Select the correct answer from the codes given below: (A) only (B) only (C) 3 only (D), and 3 f Modulation index f f k A f ka f f m m m if f m is double, is This is a case of FM. 09. What is the modulation index of an FM signal having a carrier swing of 00kHz and modulating frequency of 8kHz? (A) 4.75 (B) 5.50 (C) 6.5 (D) 7.50 Total carrier swing f f 00kHz f 50kHz f 50kHz 6.5 f 8kHz m m ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India

23 ESE-06 EC Objective Paper-II 0. In a pulse code modulated system, the number of bits is increased from 7 to 8 bits. The improvement in signal to quantization noise ratio will be (A) db (B) 4dB (C) 6dB (D) 8dB SNR q 6n db n is number of bits Thus bit change SNR change is 6dB.. In the process of modulation (A) Some characteristics of a high frequency sine wave varied in accordance with the instantaneous value of a low frequency signal (B) Parameters of carrier wave are held constant (C) For proper and efficient radiation, the receiving antennas should have heights comparable to half-wavelength of the signal received (D) The signal is converted first within the range of 0 Hz to 0Hz. If the sampling is carried out at a rate higher than twice the highest frequency of the original signal (f max ), then it is possible to receive the original signal from the sampled signal by passing it through (A) A high-pass filter with the cut-off frequency equal to f max (B) A low-pass filter with the cut-off frequency equal to f max (C) A high-pass filter with the cut-off frequency greater than f max (D) A low-pass filter with the cut-off frequency greater than f max 3. The open-loop transfer function of a unity 0( 0.s) feedback system is G(s). The ( 0.5s) phase shift at = 0 and =, will be respectively (A) 90 o and 80 o (B) 0 o and 80 o (C) 90 o and 90 o (D) 0 o and 0 o 0( 0.s) G(s) ( 0.5s) The phase shift at 0 and sys ( ) Tan [0.5 ] Tan [0. ] 0 ; 0 ; 0 4. The conversion time for a 0-bit successive approximation A/D converter, for a clock frequency of MHz is (A) s (B) 5s (C) 0s (D) 5s T sec f MHz 5. The minimum bandwidth of the link needed for a guard band of 0 khz frequency to prevent interference between six channels, each with 00kHz frequency, is (A) 45kHz (B) 575 khz (C) 650 khz (D) 75 khz Total bandwidth = = 650kHz ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 3

24 ESE-06 EC Objective Paper-II 6. The different access methods which permit many satellite users to operate in parallel through a single transponder without interfering with each other are. Frequency Division Multiple Access (FDMA). Time Division Multiple Access (TDMA) 3. Code Division Multiple Access (CDMA) Which of the above are correct? (A) and only (B) and 3 only (C) and 3 only (D), and 3 7. In an optical fibre, the pulse dispersion effect is minimized by. Using a high frequency light source. Using plastic cladding 3. Minimizing the core diameter Which of the above statement is/are correct? (A) only (B) only (C) 3 only (D), and 3 8. Consider the following statements: As compared to short-circuited stubs, open circuited stubs are not preferred because the latter. Are of different characteristics impedance. Have a tendency to radiate Which of the above statements is/are correct? (A) only (B) only (C) Both and (D) Neither nor 9. Consider the following statements for multiple access system in a satellite earth station:. Access to same repeater sub-systems and same RF channel is possible. Frequency division multiple access is used. 3. Several carries are not amplified by same TWT. Which of the above statements are correct? (A) and 3 only (B) and 3 only (C) and only (D), and 3 0. The Bode plot of the open-loop transfer function of a system is described as follows: Slope 40dB/decade < 0.rad/s Slope 0dB/decade 0.<<0rad/s Slope 0 > 0rad/s The system described will have (A) pole and zeros (B) poles and zeros (C) pole and zero (D) pole and zeros Slope 40dB/dec < 0.rad/sec Slope 0dB/dec 0. < <0 Slope 0 > 0 poles at origin At = 0. slope change 40 to 0 single zero At = 0 slope change 0 to 0 single zero Total poles and zeros ICP Intensive Classroom Program IES-Live Internet Based Classes DLP All India IES-Test Series Leaders in IES Preparation 65+ Centers across India 4