D. BJT
List II (Property) 1. Second breakdown 2. Large on-stage drop 3. Small on-state drop 4. Slow device
A B C D
a. 4 3 2 1
b. 1 2 3 4
c. 4 2 3 1
d. 1 3 2 4
117. The on-stage voltage of a GTO is a. 0.7V
b. 1–2V c. 2–3V d. >3V
118. A d.c. chopper has an average value of load current of 10 A while feeding a pure resistive load at a given time ratio and frequency. If a large inductance is placed in series with the load resistance and
operated at the same switching frequency and the same time ratio, then the average load current
a. Remains constant at 10 A b. Becomes less than 10 A c. Becomes greater than 10 A
d. Variation cannot be estimated without knowing the value of inductance
119. A chopper circuit is operating on TRC principle at a frequency of 2 kHz on a 220 V d.c. supply. If the load voltage is 170 V, the conduction and blocking period of the thyristor in each cycle are, respectively a. 3.86s and 1,14s
b. 38.6 ms and 11.4 ms c. 3.86 ms and 1.14 ms d. 0.386 ms and 0.114 ms 120.
Single-phase fully controlled converter shown in the figure is able to feed back load power to the source if the firing angle
is varied from
a. 0 to 90° and the switches S1 and S2, are closed
b. 0 to 900 and the switches S3 and S4 are closed
c. 90° to 180° and the switches S1 and S2
are closed
d. 90° to 180° and the switches S3 and S4
are closed
1 of 14
1. There are two time functions g1(t) and g2(t) with Fourier transforms G1(f) and G2 (f) repetitively. Fourier transform of
a.g1 (t) + b.g2 (t) will be (a and b in the expression are constant)
a. The convolution of a G1 (f) and bG2 (f) b. The product of a G1 (f) and bG2 (f) c. The sum of a. G1 (f) and bG2 (f) d. The product of G1
fa and G2
f b2. Bandwidth of a frequency modulated signal is
a. Zero
b. The frequency of the modulating signal c. Twice the frequency of modulating
signal d. Infinity
3. The balance equation
. .
Z A BA B can be realized using only a. AND gates
b. OR gates c. NAND gates d. NOT gates
4. Current drain form the power supply is lowest in which one of the following digital IC logic family?
a. TTL b. ECL c. MOS d. CMOS
5. A MOSFET with poly silicon gate is preferred to a MOSFET with aluminum gate since in the first case the
a. Device becomes more resistant to radiation
b. Gate can be self-aligned to source and drain
c. Isolation between adjacent devices is better
d. Gate leakage current is smaller
6. In semiconductor wafer cleaning, trichloroethylene is used to remove
a. Dust particles from the surface b. Grease from the surface
c. Impurities from within the crystal d. Moisture from the surface
7. Work function is
a. Minimum temperature at which thermion emission occurs
b. Minimum excess energy needed for thermion emission
c. Maximum temperature up to which thermion emission occurs
d. Optimum energy for thermion emission
8. For a p-type semiconductor. Fermi level lies
a. In the middle of the energy gap
b. Close to the bottom of the conduction band
c. Close to the top of the conduction band d. Close to the top of the valence band 9. The force between a charge q and a
grounded infinite conducting place kept ay a distance d form it is given by
a. 2
4 0
q
d b.
2
2
4 0
q
d
c. 2
16 0
q
d d.
2
2
16 0
q
d
10. In a source-free imperfect dielectric medium (specified by loss tangent tan ), Maxwell’s curl equation can be written as:
a. H jE
1 jtan
b. H jE
1 jtan
c. H jE
1 jtan
d. H jE
1 jtan
11. If we have a control system which is actually unstable of has too low gain or phase-margins, then for a more satisfactory performance of the system, we should report to which of the following?
1. reduce the gain of the amplifier
2. Incorporate the phase advance circuit in the system
E E LE L EC C T T RI R IC CA A L L E E NG N GI IN NE EE E R R IN I NG G
3. Use integral error compensation in the system
Select the correct answer using the codes given by
a. 1,2 and 3 b. 1 and 2 c. 1 and 3 d. 2 and 3
12. For a fixed choice of steady-state velocity-error, the use of derivative output compensation in a proportional second order control system increases which of the following?
1. Setting time
2. Undraped natural frequency 3. Damping ratio
Select the correct answer using the codes given belo9w:
a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3
13. If zrej, then which of the following is not correct?
a.
*
2 cos z z
r
b. *
2 cos z z
r j
c. r zz*
d. *
r z
z 14.
What is the fundamental frequency of the discrete-time square wave shown in the figure?
a. radian b. /2 radian c. /4 radian d. 0 radian 15.
In the figure shown, the box N contains resistors only E=1 volt and 0 volt; I = 0A and 2AV=3 volts and 2 volts; respectively.
If E =1 volt, and I is replaced by R , 2 V is equal to
a. 1 volts b. 2 volts c. 3 volts d. 4 volts 16.
In the circuit shown, the initial voltage on the capacitor v(0) =2 V and I is a unit step current source. The voltage across the capacitor, v(t) for t > 0 is
a. 1E2T b. 1E2T c. 2ET d. 2et
17. The main reason for connecting a pulse transformer at a output stage of a thyristor triggering circuit is to
a. Amplify the power of the triggering pulse
b. Provide electrical isolation
c. Reduce the turn-on time of the thyristor
d. Avoid spurious triggering of the thyristor due to noise
18. Resonant converters are basically used to a. Generate large peaky voltages b. Reduce the switching losses c. Eliminate harmonics
d. Convert a square wave into a sine wave
19.
In the circuit shown, function of diode D2
is
a. To avoid the saturation of the operational amplifier
b. To provide the negative feedback when the input is negative
c. To reduce the reverse breakdown voltage of D1
d. Insignificant and can be removed 20.
For the circuit shown in the figure, which one of the following waveforms represents the correct output?
21. For a lossless two winding single-phase transformer on NO-LOAD, the following four phasor diagrams A, B, C and D are considered. Standard symbols are being used to represent the voltage, current and flux.
Which is the correct phasor-diagram?
a. A b. B c. C d. D 22.
A normal connected 3 phase transformer is obtained by connecting three single-phase transformers I, II and III as shown above.
If transformer III is removed, the system would not operate in “one-delta” mode.
Under this condition, if voltage Vab is designed by V , the voltage 60 V is ca a. V 60
b. V180 c. V 180 d. V 60
23. A three-phase 50 Hz transmission line has a capacitance of line to neutral
= 0.01F km/ . The voltage of the line is 100 kV. The charging current per kilometer of line is
a. 314 / 3 A km
b. 3
314 /
3 10 A km
c.
3 103
314 A km/ d. 3 10 3A km/ 24.
For the power system network shown, the zero-sequence reactance’s in pu. are indicated. The zero-sequence driving point reactance of bus 3 in p.u. is
a. 0.12 b. 0.30 c. 0.10 d. 0.20
25. Which of the following are the advantages of a hard wired control over a micro programmed control?
1. It uses less hardware
2. It generates control signal faster 3. It is more reliable
Select the correct answer using the codes given below
a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1,2 and 3
26. Which one of the following memories is volatile?
a. ROM b. EPROM c. Static RAM d. None of the above
27. Match List I with List II and select the correct answer:
List I
A. Wien Bridge
B. 3-Voltmeter method C. Tn-vector meter D. Watt-hour meter List II
1. Power 2. Frequency 3. Phase
4. Maximum demand 5. Energy
A B C D
a. 2 1 4 5
b. 4 5 3 1
c. 2 5 4 1
d. 4 1 3 5
28. Match List I with List H and select the correct answer:
List I
A. Wien bridge B. Maxwell bridge C. Schering bridge
D. Anderson bridge List II
1. Measurement of resistance 2. High Q inductors
3. Measurement of frequency 4. HV capacitors
5. Low Q inductors
A B C D
a. 4 5 3 2
b. 3 2 4 1
c. 4 2 3 1
d. 3 5 4 2
29. Consider the following statements in respect of a solar cell
1. A solar cell is a large area p-n junction 2. In a solar cell the p-n junction is near
the surface
3. A solar cell is a photovoltaic device Which of the statements given above are correct?
a. 1, 2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3
30. An electrical network used as lag compensator has compensating pole and zero at pc and ZC respectively. Then, they must satisfy which of the following conditions with respect to the S-plane?
a. P is in LHS and Zc is in RHS b. Z is in LHS and PC is in RHS c. Both are in LHS and ZC < PC
d. Both are in LHS and Zc> Pc
31. The open loop transfer function of a unity feedback system is given as
1G s 1
s
. The bandwidth for this system, under open loop and closed loop operations are respectively
a. 0.5 and 1.0 rad/s b. 1.0 and 0.5 rad/s c. 1.0 and 2.0 rad/s d. 2.0 and 1.0 rad/s
32. Match List I (Time Domain Specification) with List II (Equation for Finding its Value) and select the correct answer:
List I
A. Peak overshoot B. Peak time C. Rise time
D. Setting time (2%) List II
1. /
n 12
2. 4 /
n
3. exp
/ 12
4. cos1
/ n 12
A B C Da. 3 2 4 1
b. 4 1 3 2
c. 3 1 4 2
d. 4 2 3 1
33. The average value of the waveform x(t) = 4 cos 4t — 5 sin 5t is
a. 0 b.
2 /
c. 2 / d. 20 /
34. A reciprocal two port network is symmetrical if
a. Z11 = z22 b. A 1 c. A D d. y 1
35. If an RC impedance function, Z(s), has equal number of poles and zeros at finite locations, then
a. Z
0 Z
b. Z
0 Z
c. Z
0 Z
d. Z
0 Z
36. A single-phase full-bridge, voltage source inverter, feeds a pure inductive load L and the inverter input voltage is Vs. The current through L, with a period of T second, would be a
a. Triangular wave with peak value Vs/L . T/2
b. Triangular wave with peak value VS/L T/4
c. Square wave with peak value Vs/L T/2 d. Pulsed wave with peak value Vs/L .
T/2
37. Match List I (Power converters) with List II (Industrial Drive) and select the correct answer:
List I
A. Dual converter B. DC chopper C. Cyclo converter D. Inverter
List II
1. Cement klin drive 2. Induction heating 3. Rolling mill drive 4. Electrical vehicle 5. Sugar mills
A B C D
a. 2 1 5 3
b. 3 4 1 2
c. 2 4 1 3
d. 3 1 5 2
38. Consider the following statements:
Biasing of electronic devices is done 1. To Whom It May Concern: establish
the operating point
2. To make the operating point stable 3. To use the devices as switches rather
than amplifiers
Which of the statements given above is/are correct?
a. 1 only b. 2 only c. 1 and 2 d. 1, 2 and 3
39. A differential amplifier is basically a/an a. DC amplifier
b. AC amplifier c. Chopper amplifier d. Mixer amplifier
40. The number of flags affected when a data-transfer instruction is executed by 8085 is a. 0
b. 1 c. 3 d. 5
41. The Program Counter in a computer is a special purpose register which contains a. The instruction being executed
b. The address of the instruction being executed
c. The next instruction to be expected
d. The address of the next instruction to be executed
42. A 5-h.p., 3-phase, 400 V, 4-pole, 50 Hz squirrel-cage induction motor has a full-load speed of 1440 r.p.m. At half full-full-load, the speed of this motor would be
a. 1480rp.m.
b. 1470rpm.
c. 1460r.p.m.
d. 1450rpm.
43. For a repulsion-type single-phase induction motor four configurations of the brush-axis in relation to the stator-field axis at an instant are considered.
The brush-axis is:
A. In line with the stator field-axis B. In quadrate with the stator field-axis C. Shifted forward by an angle
, 0 90
D. Shifted backward by an angle
, 0 90
Indicate from the following code the correct values of developed torque the above motioned positions:
44. The output of a diode detector contains a. The modulating signal
b. The DC voltage c. The RF ripple d. All of the above
45. Which one of the following does not give a digital output?
a. Pulse amplitude modulation b. Pulse code modulation
c. Differential pulse code modulation d. Delta modulation
46.
In QPSK modulator shown above, the blocks 1, 2 and 3 are, respectively
a. Serial to parallel converter, cos 0tand 90° phase lead
b. Serial to parallel converter, sin 0t and 900 phase lead
c. Serial to parallel converter, sin 0t and 90° phase lag
d. Parallel to serial converter, sin 0t and 90° phase lag
47. Correctly sequence the blocks for an integrating digital voltmeter from the list given below:
1. Integrator
2. Reference voltage 3. Converter 4. Control logic
Select the correct sequence out of the following
a. 1-2-4-3 b. 2-1-3-4 c. 1-2-3-4 d. 2-1-4-3
48. When a time varying signal has to be digitized using an ADO, it is necessary to use before digitization a/an
a. Time division multiplexer b. Frequency division multiplexer c. Sample and hold circuit
d. Instrumentation amplifier 49. Consider the following statements:
1. Flash AID converter is the fastest.
2. Minimum hardware is used in implementing the Flash A/D converter.
Which of the statements given above is/are correct?
a. 1 only b. 2 only c. Both 1 and 2 d. Neither 1 nor 2
50. Copper has a much lower resistively than aluminum. SiO2 has a dielectric constant of 3.9 and Xerogel has a dielectric constant of 2.1. In order to reduce the interconnect delay in VLSI circuits, what should be the best combination of metal and dielectric layer?
a. Copper with SiO2
b. Aluminum SiO2
c. Aluminium with Xerogel d. Copper with Xerogel
51. Consider the following statements concerning the ferromagnetic materials 1. There are easy and hard magnetization
directions in the ferromagnetic crystal.
2. Eddy current losses are smaller for materials having low electrical conductivity values.
3. All ferromagnetic materials can be used at high frequencies.
Which of the statements given above are correct?
a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3
52. The E-field of a uniform plane wave propagating in a dielectric medium is given by
What is the dielectric constant of the medium?
a. 1/ 3 b. 3 c. 3 d. 9
53. How long (in terms of wavelength) should the short- circuited lossless line be so as to appear as an open circuit at the input terminals?
a. t/ 4 b. l/ 2 c. l/ 3 d. l
54. Which one of the following is the capacity of standard telephone channel occupying the frequency range of 300 to 3400 Hz for an actual S/N ratio of 1023?
a. 31000 bits per second b. 306900 bits per second c. 3478200 bits per second d. 17500 bits per second
55. Consider the following statements related to the ferroelectric materials:
1. Ferroelectric state occurs below a particular temperature which is different for each material.
2. In the ferroelectric state dielectric constant is much larger than those of ordinary dielectric materials.
3. There is spontaneous polarization of the material when it is in the ferroelectric state.
Which of the statements given above are correct?
0 absolute permittivity of free space Then the relative permitted of a gas subjected to a homogeneous electric field is
57. Consider The Following Statements:
The roots of the characteristic equation of a control system lead to its instability if they lie
1. On the imaginary axis of the s-plane 2. On the negative real axis of the S-plane 3. In the right-half of the S-plane
Which of the above are correct?
58. A plane wave with an instantaneous expression for the electric field
, ax 10sin
ay 20sin
E z t E tkz E t kz is
a. Linearly polarized b. Circularly polarized c. Elliptically polarized d. Horizontally polarized
59. Additional inductance in the local circuit of a phase- controlled connection feeding a separately-excited DC motor is used to a. Limit the possible ripple content b. Avoid the possibility of discontinuous
conduction
c. Improve the line power factor
d. Increase the rising angle limit during inverter operation
60.
Which one of the following is the minimum phase transfer function that corresponds to Bode magnitude plot shown in figure?
a. 1 2s1 b. 2s 1 c. 1
1 1
2s d. 1
2s 1
61. Consider the LTI system with impulse response h t
eatu t
,a which one 0, of the following gives the response to the signal x t
eatu t
?a. y t
eatu t
b. y t
t eatc. y t
teatu t
d. y t
t e2 atu t
62.
In the circuit shown in the figure, the ammeter (which gives deflection proportional to the current through it) reading is
a. 0A b. 10A
c. Oscillates between 0 and 10A d. Oscillates between – 10A and 10A 63. Consider the following statements
In a transformer, an iron core is used to
1. Increase the useful flux 2. Educe the leakage flux 3. Reduce the useful flux
Which of the above is/are correct?
a. 2 only b. 1 and 2 c. 2 and 3 d. 3 only
64. A single-phase diode-bridge rectifier is connected to a load resistor of 50ohms.
The source voltage is v200 sint, where 250radians per second. The power dissipated in the load resistor is a. 400
w b. 32002
W c. 400W d. 800
W
65. A single-phase AC voltage controller has input voltage of 300 V and runs at 50 Hz.
The controller switch remains ON for four cycles and OFF for five cycles. The rms value of output voltage would be
a. 133.33 V b. 166.67 V c. 200V d. 300V
66. If both the inputs to a half adder are 1, the sum and carry outputs are, respectively a. 0,0
b. 0,1 c. 1,0 d. 1,1
67. The number of non-trivial logic functions in a 2-variable logic family is
a. 4 b. 10 c. 12 d. 16 68. a
A sinusoidal oscillator is buit using an amplifier of real gain A, infinite input impedance and the feedback
networkshown in the figure. If Z jX, then Z is 0 equal to
a. -2jX b. –jX c. iX d. 2jX
69. The only 16-bit long instruction in a machine code that uses immediate addressing mode in 8085 is
a. LX1,HXXXX b. LDAXXXX c. LHLDXXXX d. LMPXXXX
70. Which of the following memory units needs periodic refreshing?
a. ROM b. EPROM c. Static RAM d. Dynamic RAM
71. Two 3-phase alternators are synchronized so that their no-load voltages E1 and E2 are equal. If the excitation of machine 1 is now increased, then
1. A local circulating current I is set up.
2. Ic magnetizing in nature for machine 2.
3. Ic tends to reduce E11.
4. The terminal voltages does not change.
Which of the statements given above are correct?
a. 2 and 3 b. 1,2 and 4 c. 1, 3 and 4 d. 1, 2 and 3
72. A string insulator has 5 units. The voltage across the bottom-most is 25% of the total voltage. The string efficiency is
a. 25%
b. 50%
c. 80%
d. 75%
73. In load flow studies of a power system, a voltage control bus is specified by
a. Real power and reactive power b. Real power and voltage magnitude c. Voltage and voltage phase angle d. Reactive power and voltage magnitude
74. Band-limited White Gaussian Noise means that the spectral density of the noise
a. Is constant over a given band and has any value elsewhere
b. Is constant over a given band and has zero value elsewhere
c. Is zero over the given band and constant elsewhere
d. Varies over a given band and has zero value elsewhere
75. In a communication system, the probabilities of message occurrences are 1/8, 3/8, 1/8 and 3/8. The source entropy will be
a. 1 .8 bits/message b. 2.8 bits/message c. 3.4 bits/message d. 5.6 bits/message
76. An average response rectifier type electronic AC voltmeter has a DC voltage of 10 V applied to it. The meter reading will be
a. 7.1 V b. 10.0 V c. 11.1 V d. 22.2 V
77. Consider the following statements pertaining to strain gauges:
1. In metal strain gauge, the basic effect is a change of resistance with strain.
2. Gauge factor of metal strain gauges is larger than that of semiconductor strain gauges.
3. Gauge factor of semiconductor strain gauges varies with strain.
4. Metal strain gauges are insensitive to temperature.
Which of the statements given above is/are correct?
a. 1 and 2 b. 2 only c. 1 and 3 d. 3 and 4
78. One example of combinational circuit is a. Adder
b. Counter c. Shift register d. Flip-flop
79. A three input multiplexer will require a. A minimum of two select lines and one
output line
b. One select line and one output line c. Three select lines and one output line d. Two select lines and two output lines 80. Ion-implantation is a superior process to
diffusion because of which of the following reasons?
1. It is a high temperature process.
2. It results in precise control of depth and profile.
3. Lattice damage due to high energy ion beam can be annealed.
Select the correct answer using the codes given below
a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3
81. Consider the following process steps used in photolithography:
1. Alignment and Exposure 2. Pre-bake
3. Spinning 4. Development 5. Oxide etching 6. Post-bake
7. Photo resist stripping
The correct sequence of these process steps is
a. 3,2, 1, 5,6,4, 7 b. 2,3, 1,4, 5, 7, 6 c. 3,2, 1,4,6,5,7 d. 2,7, 1,4,3, 5,6
82. Which of the following properties does the SiO2 layer exhibit for use in IC fabrication?
1. It provides a protective conducting layer on the silicon surface.
2. It provides surface passivation
3. It serves as an insulator on the silicon surface.
4. It provides support for all IC components to be fabricated over it.
Select the correct answer using the codes given below:
a. 2 and 3 b. 3 and 4 c. 1 and 4 d. 1 and 2
83. Match List I (Element of Mechanical System) with List H (Analogous Element
in Electrical Network) and select the correct answer:
List I A. Mass B. Spring C. Damper D. Displacement List II
1. Inductance 2. Capacitance 3. Resistance 4. Charge 5. Current
A B C D
a. 1 2 3 4
b. 4 3 5 1
c. 1 3 5 4
d. 4 2 3 1
84. Three blocks G1, G2 and G3 are connected in some fashion such that overall transfer functions is 1 3
1 2
1 2
1 1
G G G G
G G
. The blocks are connected in the following manner:
a. G1, G2 with negative feedback and combination parallel with G3
b. G1, G3 with negative feedback and G2
in parallel
c. G1, G2 is cascade and combination in parallel with G3
d. G1,G3 in cascade and combination in parallel with G2
85. The unit impulse response of the system described by
1
1
y n y n X n X n a.
nb. U(n) c. 1 d. 0
86. The 3-dB cutoff frequency of a first order low pass filter is c. If the input signal is 0.5 sinct, the output will have a phase shift of
a. -45°
b. -90°
c. 45°
d. 90°
87.
In the circuit shown in the figure, voltage v is given by
a. dVc c dt V b. V c
c. dvc c dt RCV d. dvc c
RC v
dt 88.
In this circuit shown, current through R is a. 0
b. 0.5A c. 2.5A d. 3.33A 89.
The peak current through the resistance in the circuit shown is
a. 18mA b. 12mA c. 8mA d. 4mA
90. The correct sequence of the following devices in the increasing order of turn-off times is
a. MOSFET, IGBT, BJT, Thyristor b. IGBT, MOSFET, BJT,Jhyristor c. Thyristor, BJT, MOSFET, IGBT d. MOSFET, BJT, IGBT, Thyristor
91. An electric field in a charged medium with a time-varying magnetic field has
a. .E 0; E 0 b. .E 0; E 0 c. .E 0; E 0 d. .E 0; E 0
92. In HVDC transmission systems, filters are installed on
a. AC side only b. DC side only
c. Both on AC and DC sides d. Sending end only
93. The variation of near-zone electric field of a Hertzian dipole with radial distance R
93. The variation of near-zone electric field of a Hertzian dipole with radial distance R