1. The line integral of the vector potential A around the boundary of a surface S represents which one of the following?
a. Flux through the surface S
b. Flux density in the surfaces S
c. Magnetic field intensity
d. Current density
2.An infinitely along straight conductor located along Z-axis carries a current I in the +ve Z-direction. The magnetic field at any point P in the X-Y plane is in which direction?
a. In the positive Z-direction
b. In the negative Z-direction
c. In the direction perpendicular to the radial line OP (in X-Y plane) joining the origin O to the point P
d. Along the radial line OP
3.Of two concentric along conducting cylinders, the inner one is kept at a constant positive potential +V0 and the outer one is grounded. What is the electric field in the space between the cylinders/
a. Uniform and directed radially outwards
b. Uniform and directed radially inwards
c. Non-uniform and directed radially outwards
d. Non-uniform and directed parallel to the axis of the cylinders.
4. In a charge-free space, the Poisson’s equation results in which one of the following?
a. Continuity equation
b. Maxwell’s equation
c. Laplace equation
d. None of the above
5. Consider the following statements relating to the microstrip lines:
1. There is no radiation loss problem in microstrip lines.
2. Modes on microstrip line are only quasi-transverse electric and magnetic
3. Microstrip line is also called as open strip line.
Which of the statements given above are correct?
a. 1, 2 and 3
b. 1 and 2 only
c. 1 and 3 only
d. 2 and 3 only
6. Consider the following elements associated with boundary conditions between two media:
1. Normal component of B is continuous at the surface of discontinuity.
2. Normal component of D may or may not be continuous.
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
7.In a LDVT, here are two secondary coils which are connected for a single output. Which one of the following is correct?
a. The coils are in series and in phase opposition 1
b. The coils are in parallel and in phase opposition
c. The coils are in series and in the same phase condition
d. The coils are in parallel and in the same phase condition.
8.A resistance strain gauge of gauge factor 2 is used as a transducer element. Neglecting piezoresistive effect, what is the value of Poisson’s ratio?
a. 0.5
b. 1
c. 1.6
d. 2
9. Match List I with List II and select the correct answer using the code given below the lists: List I
(Thermo couple)
A. Copper Constantan
B. (Platinum Rhodium) Platinum
C. (Rhodium Indium) Indium
D. Iron-Constantan List II (Temperature range)
1. -2000C to +850 0C
2. -2000C to +350 0C
3. 00C to 10000C
4. 12000C to 2000 0C Code:
A B C D
a. 1 4 3 2
b. 2 3 4 1
c. 1 3 4 2
d. 2 4 3 1
10. Which one of the following statements is not correct?
a. Data loggers are usually of digital types
b. A digital voltmeter is essentially and A-D converter
c. A servo-type potentiometric recorder has a frequency response better than that of a galvometric recorder
d. In digital transducers, there are ergonomic advantages in presenting digital data.
11. A coil is tuned to resonance of 500 kHz with a resonating capacitor of 36 pF. At 250 kHz, the resonance is obtained with resonating capacitors of 160 pF. What is the self-capacitance of the coil?
a. 2.66 pF
b. 5.33 pF
c. 8 pF
d. 10.6 pF
12. A compensated probe of a CRO contains which of the following?
1. An amplifier
2. R-C network
3. Only resistive network
4. Only capacitive network
Select the correct answer using the code given
below:
Code:
a. 1 and 2 only
b. 2 only
c. 3 only
d. 4 only
13.The accuracy of a 0.10 mA meter is +2%.What is its accuracy while taking a reading of 5mA?
a. + 0.5%
b. + 1%
c. + 2%
d. + 4%
14. Match List I with List II and select the correct answer using the code given below the lists: List I
(Term)
A. Relative error
B. Precision a
C. Calibration
D. Resolution List II . (Statement)
1. The ability of the device to give identical output when repeat measurements are made with the same input signal
2. The ratio of difference between measured value and the true value to the true value of the measured
3. The smallest increment in measured that can be detected with certainty by the instrument
4. The process of making adjustments on the scale so that the instrument readings conform to an accepted standard
Code:
A B C D
a. 2 3 4 1
b. 4 1 2 3
c. 4 3 2 1
d. 2 1 4 3
15. If R, L and C are the parameters of a resistor, what is the condition for the resistor to be non-inductive?
a. L = CR
b. L = CR2
c. C = LR2
d. C = R/L
16. What precaution(s) is/are required for absolute measurement of current by Rayleigh current balance?
1. Precision balance of special form must be used for the accuracy of measurement
2. The flexible leads, used for taking current into the moving coil, must not expert appreciable torque upon the moving system
Select the correct answer using the code given
below:
Code:
a. 1 only
b. 2 only
c. Both 1 and 2
d. Neither 1 and 2
17. In a rectangular waveguide
a. TE and TEM waves can exist but TM waves cannot exist
b. TM and TEM waves can exist but TE waves cannot exist
c. TE and TM waves can exist but TEM waves cannot exist
d. TE, TM and TEM all can exist.
18. Which one has the lowest attenuation in a circular waveguide?
a. TM11
b. TE11
c. TE10 d. TE01
19. In a parallel plate waveguide, what is the principal wave?
a. TEM wave
b. T wave
c. TM wave
d. Combination of TE and TM waves having axial components of both electric and magnetic fields
20. According to Poynting theorem, the vector
product E x H is a measure of which one of
the following?
a. Stored energy density of the electric field
b. Stored energy density of the magnetic field
c. Power dissipated per unit volume
d. Rate of energy flow per unit area
21. When does the maximum radiation for an end-fire array occur?
a. Perpendicular to the line of the array only
b. Along the line of the array only
c. At 450 to the line of the array
d. Both perpendicular to and along the line of the array
22. As the aperture area of an antenna increases, its gain
a. Increases
b. Decreases
c. Remain steady
d. Behaves unpredictably
23. Which of the following capacitors are made use of widely for a capacitance application in monolithic ICs?
1. MOS capacitor
2. Collector-Substrate capacitor
3. Collector-Base capacitor
4. Base-Emitter capacitor
Select the correct answer using the code given
below:
Code:
a. 1 and 2 only
b. 2 and 3 only
c. 3 and 4 only
d. 1 and 4 only
24. In a network containing active components, output voltage
a. will always be greater than input voltage
b. will always be equal to the input voltage
c. can be less than or greater than input voltage only
d. will be less than, equal to or greater than input voltage
25.intrinsic semiconductor is doped lightly with p-type impurity. It is found that the conductivity actually decreases till a certain doping level is reached. Why does this occur?
a. The mobility of holes decreases
b. The mobility of both electrons and holes decreases
c. The hole density actually reduces
d. Effect of reduction in electrons due to increase in holes compensates more than the effect of increase in holes on conductivity
26. Assuming that the electron mobility in intrinsic silicon is 1500 cm2/Vs at room temperature (T=300 K) and the corresponding’ volt equivalent of temperature’ VT = 25.9 mV, what is the approximate value of the electron diffusion constant?
a. 40 cm2/s
b. 4 cm2/s
c. 400 cm2/s
d. 4000 cm2/s
27. The ‘voltage stability with time’ of reference diodes incorporating Zener diodes is comparable to that of which of the following?
a. Dry cells
b. Nickel-cadmium cells
c. Lead-acid accumulator batteries
d. Conventional standard cells
28. In a MOSFET, the transfer characteristics can be used to determine which of the following device parameters?
a. Threshold voltage and output resistance
b. Trans-conductance and output resistance
c. Threshold voltage and trans-conductance
d. Trans-conductance and channel length modulation parameter
29. Assuming an operating temperature T = 300 K and corresponding VT = 25 mV, what is the change in semiconductor silicon diode forward voltage VD to produce a 10:1 change in diode current ID, while operating in the forward bias region (< 25 mA)?
a. 60 mV
b. 120 mV
c. 180 mV
d. 240 mV
30. The doping concentration on the n-side of a p-n junction diode is enhanced. Which one of the following will get affected?
a. Width of the depletion region on n-side
b. Width of the depletion region on p-side
c. Width of the depletion region on both sides
d. No change in width of depletion regions
31.In a step-graded p-n junction diode, what is the ratio of depletion region penetration depths into p and n regions (if the ratio of accentor to donor impurity atoms’ densities of 1:2)?
a. 2 : 1
b. 4 : 1
c. 1 : 2
d. 1 : 4
32.What is the most noticeable effect of a small increase in temperature in the common emitter connected BJT?
a. Increase in Ice
b. Increase in output resistance
c. Decrease in forward current gain
d. Increase in forward current gain
33.While using a bipolar junction transistor as an amplifier, the collector and emitter terminals got interchanged mistakenly. Assuming that the amplifier and the biasing is suitably adjusted, the interchange of terminals will result into which one of the following?
a. Zero gain
b. Infinite gain
c. Reduced gain
d. No change in gain at all
34.In n-channel enhancement MOSFET, at a fixed drain voltage
a. the drain current is maximum at zero gate voltage and it decreases with applied negative gate voltage
b. the drain current has a finite value at zero gate voltage and it increases or decreases with the applied voltage of proper polarity
c. the drain current is zero at zero gate voltage and it increases with the positive applied gate voltage
d. the drain current is zero for negative bias voltage to gate and it increases as negative gate bias is decreased in magnitude
35. The data sheet for a certain JFET (Junction Field Effect Transistor) indicates that LDSS (drain to source current with gate shorted) = 15 mA and VGS (off) (cut-off value of gate to source voltage)= -5 V. What is the drain current for VGS = -2 V?
a. 58.8 mA
b. 29.4 mA
c. 9.6 mA
d. 5.4 mA
36. What one of the following devices can be turned ‘ON’ of ‘OFF’ by applying gate signal?
a. CSR
b. SCS
c. TRIAC
d. UJT
37. Why is silicon dioxide (SiO2) layer used in ICs?
a. To protect the surface of the chip from external contaminants and to allow for selective formation of the n and p regions by diffusion
b. Because it facilitates the penetration of the desired impurity by diffusion
c. To control the concentration of the diffused impurities
d. Because of its high heat conduction
38.Why is the term ‘planner technology’ for fabrication of devices in ICs used?
a)The variety of manufacturing processes by which devices are fabricated, takes place
through a single plane
b)The aluminum contacts to the collector,base and emitter regions of the transistors
in the ICs are laid in the same plane
c)The collector, base and emitter regions ofthe transistors in ICs are laid in the sameplane
d)The device looks like a thin plane wafer
39.In an optional fibre, the light beam propagates due to which one of the following?
a. Simply reflection of light at a boundary between two media
b. Refection of light in the medium
c. Total internal reflection at the boundary of the fibre
d. Scattering of light in the medium
40.Dispersion in an optical fibre used in a communication link is of which type?
a. Angular dispersion
b. Modal dispersion
c. Chromatic dispersion
d. Dispersion arising due to structural irregularities in the fibre.
41. What is the average power for periodic non-sinusoidal voltage and currents?
a. The average power of the fundamental component alone
b. The sum of the average powers of the harmonics excluding the fundamental
c. The sum of the average powers of he sinusoidal components including the fundamental
d. The sum of the root mean square power of the sinusoidal components including the fundamental
42. The Fourier transform of a function is equal to its two-sided Laplace transform evaluated
a. on the real axis of the s-plane
b. on a line parallel to the real axis of the s-plane
c. on the imaginary axis of the s-plane
d. on a line parallel to the imaginary axis of the s-plane
43.For matching of a radio frequency coaxial line to a purely reactive load
a. quarter-wave transformer would work better than stub matching
b. stub matching would work better than quarter wave transformer
c. both quarter wave transformer and stub matching techniques would work equally well
d. both quarter-wave transformer and stub matching techniques would fail
44. If an infinite homogeneous isotropic medium is modeled as an equivalent transmission line, the characteristic impedance of the corresponding transmission line is known as
a. characteristics impedance
b. iterative impedance
c. wave impedance
d. intrinsic impedance
45. Match List I with List II with respect to the synthesis of R-C driving point function Z(s) = 68. 1/Y(s) and select the correct answer using the
code give below the lists:
List I
(Form)
A. Foster I form
B. Foster Ii form
C. Cauer I form
D. Cauer II form List II (Method)
1. Continued fraction expansion of Z(s) around s = oo
2. Partial fraction expansion of Y(s)/s
3. Continued fraction expansion of Z(s around s = 0
4. Partial fraction expansion of Z(d)
Code:
A B C D
a. 1 2 4 3
b. 4 3 1 2
c. 1 3 4 2
d. 4 2 1 3
46.The lowest and the highest critical frequencies of an R-L driving point impedance are, respectively
a. a zero, a pole
b. a pole, a pole
c. a zero, a zero
d. a pole, a zero
47. A two port network has z11 = 11/35, z12 = z21 = 2/35, z22 = 3/35. Its y11 and y12 parameter will, respectively, be
a. 3, -2
b. 3, 2
c. 13, -2
d. 13, 2
48.A reciprocal two-port network is symmetrical if
a. AA = 1
b. A = C
c. z11 = z22
d. Ay =1
49.Inside a waveguide with perfectly conducing walls, any current present is in the form of
a. displacement current only
b. conduction current only
c. partially displacement current and partially conduction current
d. sometimes displacement current and sometimes conduction current
50.Which one of the following is a passive transducer?
a. Piezoelectric
b. Thermocouple
c. Photovoltanic cell
d. LVDT
51.Which one of the following materials is not used as a piezoelectric transducer?
a. Rochelle salt
b. Lithium sulphate
c. Barium titanate
d. Tungsten oxide
52.Which one of the following modulation techniques is the most efficient for pulse telemetry?
a. PAM
b. PCM
c. PDM
d. PPM
Direction:
Each of the following items consists of two statements, one labeled as ‘Assertion (A)’ and the other as ‘Reason (R)’. You are to examine these two statements carefully and select the answers to these items using the code given below: Code:
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
53. Assertion (A): The z-transform of the output of an ideal samplers is given by
Z[f( t )] = K0+ K 1 + K 2 +.. + Kn
Reason (R): The relationship is the result of application of z = e-sT, where T stands for the time gap between the samples.
54. Assertion (A): The Kirchhoff s current law states that the sum of currents entering at any node is equal to the sum of currents leaving that node.
Reason (R): The Kirchhoff s current law is based on the law of conservation of charge.
55. Assertion (A): In a linear network, the superposition theorem can be used to calculate power dissipation in a resistive branch of the network.
Reason (R): Superposition theorem is valid for currents and voltages, and therefore is valid also for power dissipation.
56.Assertion (A): Power factor is defined as the ratio of apparent power to the average power in an a.c. circuit.
Reason (R): The magnitude of power factor is always less than unity.
57. Assertion (A): Sinusoidal response in an a.c. circuit can be represented in rectangular form as v = Vcos 6 + jVsin 9, exactly in a way similar to vectors which we come across for force analysis in mechanics.
Reason (R): Phasors are nothing but vectors.
58.Assertion (A): VTVM gives more accurate reading compared to the accuracy of PMMC type of indicating instrument used in it, while measuring voltages across high resistances.
Reason (R): The electronic circuits used in VTVM make it more accurate by increasing its sensitivity.
59.Match List I and List Ii and select the correct answer using the code given below the lists: List-I
(Theorem/Law)
A. Norton’s theorem
B. Superposition theorem
C. Thevenin’s theorem
D. Kirchhoffs current law List II
(Property)
1. Effect of independent sources in a linear circuit are additive
2. Law of non-accumulation of change holds good at nodes
3. Current source with shunt resistor
4. Voltage source with series resistor Code:
A B C D
a. 2 4 1 3
b. 3 1 4 2
c. 2 1 4 3
d. 3 4 1 2
60. Which of the following statements are associated with Thevenin’s theorem?
1. Impedance through which current is required is removed and open-circuit voltage is found
2. It is applicable to only d.c. circuits
3. The network is replaced by a voltage source and a series impedance remains after removing the load impedance.
Select the correct answer using the code given
below:
Code:
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2 and 3
More questions in Part 2 of Paper I Elecronics
Coming Soon
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