dy Given y x2 2x 10, the value of is equal to 1. dx x 1 (A) 0 (B) 4 (C) 12 (D) 13 sin x lim is 2. x x 0 (D) (A) Indeterminate (B) 0 (C) 1 3. The power supplied by the dc voltage source in the circuit shown below is 3 6 1 3V (A) 0W (B) 1.0W (C) 2.5W (D) 3.0W 4. The current I supplied by the dc voltage source in the circuit shown below is I 1 1A 1V (A) 0A (B) 0.5A (C) 1A (D) 2A 5. For signal conditioning of a piezoelectric type transducer we require (A) a charge amplifier (B) a differential amplifier (C) an instrumentation amplifier (D) a transconductance amplifier 6. A linear variable differential transformer (LVDT) is (A) a displacement transducer (B) an impedance matching transformer (C) a differential temperature sensor (D) an auto transformer 7. The temperature being sensed by a negative temperature coefficient (NTC) type thermistor is linearly increasing. Its resistance will (A) linearly increase with temperature (B) exponentially increase with temperature (C) linearly decrease with temperature (D) exponentially decrease with temperature 8. For a single stage BJT common base amplifier (A) current gain as well as voltage gain can be greater than unity (B) current gain can be greater than unity but voltage gain is always less than unity (C) voltage gain can be greater than unity but current gain is always less than unity (D) current gain as well as voltage gain is always less than unity In the circuit shown below, the ideality factor of the diode is unity and the 9. voltage drop across it is 0.7V. The dynamic resistance of the diode at room temperature is approximately 1.7V 1k (A) 15 (B) 25 (C) 50 (D) 700 10. An ideal op-amp has the characteristics of an ideal (A) voltage controlled voltage source (B) voltage controlled current source (C) current controlled voltage source (D) current controlled current source 11. The inverters in the ring oscillator circuit shown below are identical. If the output waveform has a frequency of 10 MHz, the propagation delay pf each inverter is output (B) 10 ns (C) 20 ns (D) 50 ns (A) 5 ns 12. A 2K�8 bit RAM is interfaced to an 8-bit microprocessor. If the address of the first memory location in the RAM is 0800H, the address of the last memory location will be (A) 1000H (B) 0FFFH (C) 2848H (D) 47FFH 5 f n 6 The fundamental period of the discrete-time signal x n e 13. is 6 12 (A) (B) (C) 6 (D) 12 5 5 14. Which one of the following discrete-time systems is time invariant? (A) y n nx n (B) y n x 3n (C) y n x n (D) y n x n 3 If a current of 6 2 sin 100t 6 2 cos 300t A is passed through a true 15. 4 RMS ammeter, the meter reading will be (C) 12A (A) 6 2A 126A (D) 216A (B) 16. If the ac bridge circuit shown below is balanced, the element Z can be a (A) Pure capacitor : Detector (B) Pure inductor D (C) R-L series combination (D) R-L parallel combination Z 17. The Bode asymptotic plot of a transfer function is given below. In the frequency range shown, the transfer function has dB 20dB / decade 20dB / decade 0dB / decade log 1 2 (A) 3 poles ands 1 zero (B) 1 pole and 2 zeros (C) 2 poles and 1 zero (D) 2 poles and 2 zeros 18. For radioisotope imaging, an Anger camera is fitted with a parallel hole collimator. If the thickness of the collimator is increased, the camera (A) resolution and sensitivity will increase (B) resolution and sensitivity will decrease (C) resolution will increase and sensitivity will decrease (D) resolution will decrease and sensitivity will increase 19. In the standard 12-lead ECG recording system, the minimum number of electrodes required to be attached to a human subject for recording any one of the unipolar chest lead signals is (A) 1 (B) 2 (C) 4 (D) 5 20. A laser light with a wavelength of 633nm is passed through 1cm length of tissue and 2cm length of glass. The refractive indices of tissue ad glass are 1.33 ad 1.5 respectively. The velocities of laser light in the tissue and in the glass are in the ratio of (A) 1.33:0.75 (B) 1.33:3.0 (C) 1.33:15 (D) 1.5:1.33 Q. No. 21 � 75 Carry Two Marks Each The expression e ln x for x 0 is equal to 21. (C) x-1 (D) -x-1 (A) -x (B) x dy 1 y2 . Which one of the following can be 22. Consider the differential equation dx a particular solution of this differential equation? (A) y tan x 3 (C) x tan y 3 (B) y tan x 3 (D) x tan y 3 Consider the function y=x2-6x+9. The maximum value of y obtained when x 23. varies over the interval 2 to 5 is (A) 1 (B) 3 (C) 4 (D) 9 It is known that two roots of the nonlinear equation x3 6x2 11x 6 0 are 1 24. and 3. The third root will be (A) j (B) - j (C) 2 (D) 4 25. Consider a Gaussian distributed random variable with zero mean and standard deviation . The value of its cumulative distribution function at the origin will be (A) 0 (B) 0.5 (C) 1 (D) 10 26. A random variable is uniformly distributed over the interval 2 to 10. Its variance will be 16 256 (A) (B) 6 (C) (D) 36 3 9 The Fourier transform of x t e atu t , where u t is the unit step function 27. (A) Exists for any real value of a (B) Does not exist for any real value of a (C) Exists if the real value of a is strictly negative (D) Exists if the real value of a is strictly positive 28. In the circuit shown below the maximum power that can be transferred to the load ZL is i t 10 2 sin 1000t A (A) 250W A complete variable Z x j 0.1 has its real part x varying in the range 29. to . Which one of the following is the locus (shown in thick lines) of 1/Z in the complex plane? (A) Real axis ^ -j10 (C) Image axis 10 ZL 10mH (B) 500W (C) 1000W (B) (D) Image axis (D) 2000W Image axis Image axis Real axis ^ -j10 Real axis Real axis -j10 -j10 V1 For the circuit shown below the input resistance R11 is 30. I1 I2 0 3I2 2 1 2V3 I1 I2 V1 V2 2 V3 (A) 3 (B) 2 (C) 3 (D) 13 In the circuit shown below the average power consumed by the 2 resistor is 31. 1 10 2 sin 1000t V : 1mH 100 2 sin 3000t V : (A) 50W (B) 1050W (C) 5000W (D) 10100W 32. Which one of the following equations is valid for the circuit shown below? 1 1 I1 I3 1 1 I2 I6 1 I5 5V 1 1 I4 I7 (A) I3 I5 I6 I7 0 (B) I3 I5 I6 I7 0 (C) I3 I5 I6 I7 0 (D) I3 I5 I6 I7 0 33. For the circuit shown below the steady-state current I is I 1 v t 5 2e5t cos 1000t V 1000 F 1mH (B) 5 2 cos 1000t A (A) 0 A (D) 5 2 A (C) 5 2 cos 1000t A 4 34. For the circuit shown below the voltage across the capacitor is j100 10 j0 V j100 10 j 0 V 100 j0 V 0 j100 V (D) 0 j100 V (B) (C) (A) 35. The speed of a gear having 60 teeth is measured using a proximity sensor. The output of the proximity sensor is fed to a counter with a gating time of 1s. The counter indicates a value of 120. The speed at which the gear is rotating is (A) 60 rpm (C) 600 rpm (D) 1200 rpm 36. A piezoelectric type accelerometer has a sensitivity of 100mV/g. The transducer is subjected to a constant acceleration of 5g. The steady state output of the transducer will be (A) 0V (C) 0.5V (D) 5V 37. A pair of identical thermocouples is employed for measuring the temperature of a specimen as shown below. The characteristic is tabulated below. The reference junction is at 20C. The meter reads 48 V . The correct temperature of the specimen is Specimen 10 : (B) 120 rpm (B) 100mV + V meter - - + Reference junction Temperature (0C) 0 10 20 30 40 50 60 70 80 90 Output ( V ) 35 45 55 65 75 85 95 105 115 125 (A) 130 C (B) 460 C (C) 480 C (D) 500 C A strain gauge has a nominal resistance of 600 and a gauge factor of 2.5. The 38. strain gauge is connected in a dc bridge with three other resistances of 600 each. The bridge is excited by a 4V battery. If the strain gauge is subjected to a strain of 100 m / m , the magnitude of the bridge output will be (B) 250V (C) 500V (D) 750V (A) 0V 39. The torque in a rotating shaft is measured using strain gauges. The strain gauges must be positioned on the shaft such that the axes of the strain gauges are at (A) 00 with respect to the axis of the shaft (B) 300 with respect to the axis of the shaft (C) 450 with respect to the axis of the shaft (D) 900 with respect to the axis of the shaft 40. To reduce the effect of fringing in a capacitive type transducer (A) the transducer is shielded and the shield is kept at ground potential (B) a guard ring is provided ad it is kept at ground potential (C) the transducer is shielded and the shied is kept at the same potential as the moving plate (D) a guard ring is provided and it is kept at the same potential as the moving plate 41. A differential amplifier shown below has a differential mode gain of 100 and a CMRR of 40dB. If V1 0.55V and V2 0.45V, the output V0 is V1 V0 V2 (A) 10V (B) 10.5V (C) 11V (D) 15V 42. The op-amp circuit shown below is that of a Vin 1F v0 1k 1k 1k (A) low-pass filter with a maximum gain of 1 (B) low-pass filter with a maximum, gin of 2 (C) high-pass filter with a maximum gain of 1 (D) high-pass filter with a maximum gain of 2 In the op-amp circuit shown below is that of a vin is gradually increased from -10V 43. to +10V. Assuming that the output voltage vout saturates at -10V and +10V, vout will change from Vin v0 9k 1k (A) 10V to +10V when vin 1V (B) 10V to +10V when vin 1V (C) 10V to -10V when vin 1V (D) 10V to -10V when vin 1V For the op-amp circuit shown below v0 is approximately equal to 44. 10V 1M 105 95 100k v0 100k 95 105 1M (A) -10V (B) -5V (C) +5v (D) +10V In the amplifier circuit shown below, assume VBE 0.7V and the of the 45 transistor and the values of C1 and C2 are extremely high. If the amplifier is VCC designed such that at the quiescent point its VCE , where VCC is the power 2 vout supply voltage, its small signal voltage gain will be vin 10V RC 8.8k vout C2 vin C1 1.2k RE (A) 3.75 (B) 4.5 (C) 9 (D) 19 46. The result of (45)10 � (45)16 expressed in 6-bit 2's complement representation is (A) 011000 (B) 100111 (C) 101000 (D) 101001 47. The output F of the multiplexer circuit shown below expressed in terms of the inputs P, Q and R is R I0 I1 R 4 1 Y F MUX R I2 R I3 S1 S0 Q P (B) F PQ QR RP (C) F P Q R (D) F P Q R (A) F P Q R 48. A part of a program written for an 8085 microprocessor is shown below. When the program execution reaches LOOP2, the value of register C will be SUB A MOV C, A LOOPI: INR A DAA JC LOOP2 INR C JNC LOOPI LOOP2: NOP (A) 63H (B) 64H (C) 99H (D) 100H 49. The minimum sum of products form of the Boolean expression Y P QR SP QR SP QR SP QR SP QR SP QR S is (C) Y P Q QR S (D) Y QS PQR (A) Y P Q Q S (B) Y P Q Q R S 50. An X-ray tube is operated at 80kV anode voltage. In order to filter the low intensity X-rays, a 2.5mm thick aluminium filter is used. It is given that at 80kV anode voltage, the mass attenuation coefficients and densities of aluminium are 0.02m2kg1 and 2699kgm3 respectively and for copper these are 0.075m2kg1 and 8960 kgm3 respectively. If a copper filter is to replace the aluminium filter with the same effect, the thickness of the copper filter should be (A) 0.2mm (B) 0.66mm (C) 1.5mm (D) 5mm 51. A 5 MHz acoustic pulse travels from a transducer through a 2cm thick fat tissue before it encounters ad interface with a liver tissue at normal incidence. The amplitude attenuation factors of fat and liver are 0.075 Npcm1 / MHz and 0.1Npcm1 / MHz respectively. The amplitude reflectivity coefficient of fat-liver interface is 0.1. Taking both attenuation and reflection losses into a account, the amplitude loss (in dB) of echo pulse when it returns to the transducers is (A) 0.74 (B) -2.6 (C) -6 (D) -33 Consider a discrete-time LTI system with input x n n n 1 and impulse 52. response h n n n 1 . The output of the system will be given by (A) n n 2 (B) n n 1 (C) n 1 n 2 (D) n n 1 n 2 53. Consider a discrete-time system for which the input x[n] and the output y[n] are 1 related as y n x n y n 1 . If y n 0 for n 0 and x n n , then y n 3 can be expressed in terms of the unit step u[n] as n n 1 1 3n u n n (D) 3 u n u n (B) u n (C) (A) 3 3 If the bandwidth of a low-pass signal g(t) is 3kHz, the bandwidth of g2 t will be 54. 3 kHz (B) 3kHz (C) 6kHz (D) 9kHz (A) 2 Consider the AM signal s t 1 m t cos 2fc t . It is given that the bandwidth 55. of the real, low-pass message signal m(t) is 2kHz. If fc 2MHz , the bandwidth of the band-pass signal s(t) will be (A) 2.004MHz (B) 2MHz (C) 4kHz (D) 2kHz 56. Ten, real, band-pass message signals, each of bandwidth 3kHz, are to be frequency division multiplexed over a band-pass channel with bandwidth B kHz. If the guard band in between any two adjacent signals should be of 500 Hz width and there is no need to provide any guard band at the edges of the band-pass channel, the value of B should be at least (A) 30 (B) 34.5 (C) 35 (D) 35.5 57. The region of convergence of the z-transform of the discrete-time signal x n 2n u n will be 1 1 (A) z 2 (B) z 2 (C) z (D) z 2 2 The step response of a linear invariant system is y t 5e10tu t , where u(t) is 58. the unit step function. If the output of the system corresponding to an impulse input t is h t , then h t is (A) 50e10tu t (B) 5e10t t (C) 5u t 50e10t t (D) 5 t 50e10tu t 59. A 2A full-scale PMMC type dc ammeter has a voltage drop of 100 mV at 2A. The meter can be converted into a 10A full-scale dc ammeter by connecting a (A) 12.5 m resistor in parallel with the meter (B) 12.5 m resistor in series with the meter (C) 50.0 m resistor in parallel with the meter (D) 50.0 m resistor in series with the meter A 31⁄2 digit, 200 mV full scale DVM has an accuracy specification of 0.5% of 60. reading plus 5 counts. When the meter reads 100 mV, the voltage being measured is (A) Any value between 99.5 mV and 100.5 mV (B) Any value between 99.0 mV and 101.0 mV (C) Exactly 99.5 mV (D) Exactly 100 mV 61. A 230 V, 5A, 50 Hz single phase house service energy meter has a meter constant of 360 rev/kWhr. The meter takes 50 s for making 51 revolutions of the disc when connected to a 10 kW, unity power factor load. The error in the reading of the meter is (A) 0% (B) +0.5% (C) -2.0% (D) +2.0% 62. The op-amp based circuit of a half wave rectifier electronic voltmeter shown below uses a PMMC ammeter with a full scale deflection (FSD) current of 1 mA and a coil resistance of 1k . The value of R that gives FSD for a sinusoidal input voltage of 100 mV (RMS) is Sinusoidal input 1k PMMC ameter R (A) 45 (B) 67.5 (C) 100 (D) 144.4 63. The x and y sensitivities of an analog oscilloscope are set as 2 ms/cm and 1V/cm respectively. The trigger is set at 0V with negative slope. An input of 2 cos 100t 300 V is fed to the y input of the oscilloscope. The waveform seen on the oscilloscope will be (A) (B) (C) (D) 64. The open loop transfer function of a unity feedback system is K s 2 G s . The root locus plot of the system has s 1 j1 s 1 j1 (A) two breakaway points located at s 0.59 and s 3.41 (B) one breakaway point located at s 0.59 (C) one breakaway point located at s 3.41 (D) one breakaway point located at s 1.41 65. If a first order system and its time response to a unit step input are as shown below, the gain K is y K r t y t 0.8 1 ST t (A) 0.25 (B) 0.8 (C) 1 (D) 4 x 0 1 1 x u 0 3 0 . 66. The state space representation of a system is given by y 1 0 x Y s The transfer function of the system will be U s 1 1 1 1 (A) (B) (C) (D) s s 3 s2 s s3 A closed loop control system is shown below. The range of the controller gain KC 67. which will make the real parts of all the closed loop poles more negative than -1 is 1 KC s s 3 Y s R s (A) KC 4 (B) KC 0 (C) KC 2 (D) KC 2 68. For the closed loop system shown below to be sable, the value of time delay TD (in seconds) should be less than 1 Y s R s s esTD (A) (B) (C) (D) 4 2 3 69. A tissue with a refractive index 1.33 is introduced on one of the light paths of a Michelson interferometer operating with a monochromatic coherent light source of wavelength 589nm. After the introduction of a tissue sample of thickness t , the fringe pattern is observed to shift by 50 fringes. If the thickness is 2t , the fringe pattern will shift by (A) 25 fringes (B) 50 fringes (C) 100 fringes (D) 200 fringes 70. In the process of non-destructive testing of a 10cm diameter cylinder, a cross- sectional (trans-axial) image of the cylinder is reconstructed with the help of parallel beam computer tomography technique. To realize a spatial resolution of 1mm in the image, the minimum number of ray sample in each projection set and the minimum number of projection sets required are (A) 200 and 315 respectively (B) 100 and 315 respectively (C) 200 and 629 respectively (D) 100 and 629 respectively Common Data Questions 71, 72 & 73 A data acquisition system (DAS) shown below employs a successive approximation type 12-bit ADC having a conversion time of 5 s. A B Filter Filter Y Filter Filter 71. The quantization error of the ADC is (B) 0.012% (C) 0.024% (D) 0.048% (A) 0% 72. The system is used as a single channel DAS with channel 1 selected as input to the ADC which is set in the continuous conversion mode. For avoiding aliasing error, the cutoff frequency fc of the filter in channel 1 should be (A) fc 100kHz (B) fc 100kHz (C) 100kHz fc 200kHz (D) fc 200kHz 73. If the multiplexer is controlled such that the channels are sequenced every 5 s as 1, 2, 1, 3, 1, 4, 1, 2, 1, 3, 1, 4, 1......, the input connected to channel 1 will be sampled at the rate of (A) 25k samples/s (B) 50k samples/s (C) 100k samples/s (D) 200k samples/s Common Data Questions: 74 & 75 Laser light is generated by energizing helium-neon gas in a chamber. The ground and metastable states of helium are 0eV and 20.61eV respectively. The ground, higher and metastable energies of neon is 0eV, 18.70eV and 20.66eV respectively. The values of speed of light, Planks constant and charge of electron are 3 108 m / s, 6.625 1034 Js and 1.6 1019 C respectively 74. In this process, helium molecules (A) play no role (B) produce laser light (C) give energy to neon molecules (D) absorb energy from neon molecules 75. Wavelength of laser light generated in this process is (A) 61.6nm (B) 66.4nm (C) 633.8nm (D) 650.3nm Linked Answer Questions: Q.76 to Q.85 Carry Two Marks Each Statement for Linked Answer Questions: 76 & 77 In the Wheatstone bridge shown below the galvanometer G has a current sensitivity of 1 A / mm , a resistance of 2.5k and a scale resolution of 1 mm. Let R be the minimum increase in R from its nominal value of 2 k that can be detected by this bridge. 3k 6k 15V G A R VAN 4k N When R is 2 k R, VAN is 76. (A) 6 V (B) 6.0024 V (C) 6.0038V (D) 6.005 V The value of R is approximately 77. (A) 2.8 (B) 3.4 (C) 5.2 (D) 12 Statement for Linked Answer Questions 78 & 79 In the circuit shown below the steady-state is reached with the switch K open. Subsequently the switch is closed at time t = 0 1 I2 K I t0 I1 2 1H 5V 10V 1F At time t 0 , current I is 78. 5 5 (D) A (A) A A (B) 0A (C) 3 3 dI2 At time t 0 , is 79. dt 10 (B) A /s (A) 5A / s (C) 0A / s (D) 5A / s 3
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