1) According to depth of penetration, what is the percentage proportion of attenuated wave w.r.t its original value?
a. 17%
b. 27%
c. 37%
d. 57%
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2) Linear polarization can be obtained only if the wave consists of ________
a. Ex
b. Ey
c. Both Ex & Ey & in phase
d. Both Ex & Ey & out of phase
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3) When an electromagnetic wave travels from transmitter to receiver, which factor/s affect/s the propagation level?
a. Curvature of earth
b. Roughness of earth
c. Magnetic field of earth
d. All of the above
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4) For avoiding ground losses, better is the surface conductivity, less is the __________
a. Attenuation
b. Phase velocity
c. Propagation constant
d. Tilt angle
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5) On which factors of earth does the magnitude of tilt angle depend in surface wave?
A. Permittivity
B. Conductivity
C. Resistivity
D. Reflectivity
a. A & B
b. C & D
c. A & C
d. B & D
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6) What is the direction of varying orientation of polarized surface wave at the earth surface in a wave tilt mechanism?
a. Horizontal
b. Vertical
c. Diagonal
d. Opposite
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7) Which layer has the atmospheric conditions exactly opposite to that of standard atmosphere?
a. Depression layer
b. Regression layer
c. Inversion layer
d. Invasion layer
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8) If the maximum electron density for F-layer in ionosphere is 4 x 106 electrons/cm3, then what will be the critical frequency of EM wave for F-layer?
a. 4 MHz
b. 9 MHz
c. 18 MHz
d. 25 MHz
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9) According to Secant law, which frequency is greater than critical frequency by a factor of secθi?
a. MUF
b. LUF
c. OWF
d. UHF
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10) How is the effect of selective fading reduced?
A. By high carrier reception
B. By low carrier reception
C. By single side band system
D. By double side band system
a. A & C
b. B & D
c. A & D
d. B & C
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11) In lens antenna, what kind of wave energy is transformed into plane waves?
a. Convergent
b. Divergent
c. Contingent
d. Congruent
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12) What is the functioning role of an antenna in receiving mode?
a. Radiator
b. Converter
c. Sensor
d. Inverter
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13) In radio communication link, what is the shape/nature of waves generated by transmitting antenna?
a. Spherical
b. Plane
c. Triangular
d. Square
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14) Which among the following elucidate the generation of electromagnetic waves?
A. Ampere's law
B. Faraday's law
C. Gauss's law
D. Kirchoff's law
a. A & B
b. B & C
c. A & C
d. B & D
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15) If an antenna draws 12 A current and radiates 4 kW, then what will be its radiation resistance?
a. 22.22 ohm
b. 27.77 ohm
c. 33.33 ohm
d. 39.77 ohm
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16) Under which conditions of two unit vectors, the polarization loss factor (PLF) is equal to unity?
a. Perpendicular
b. Perfectly aligned
c. Angle inclination (Ψp)
d. All of the above
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17) Which property/ies of antenna is/are likely to be evidenced in accordance to Reciprocity theorem?
a. Equality of impedances
b. Equality of directional patterns
c. Equality of effective lengths
d. All of the above
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18) Self impedance of an antenna is basically __________
a. Its input impedance during the removal of all other antennas
b. Its impedance by taking into consideration the consequences of other antennas
c. Both a and b
d. None of the above
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Answer
Explanation
Related Ques
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ANSWER: Its input impedance during the removal of all other antennas
Explanation:
No explanation is available for this question!
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19) In solution evaluation process of inhomogeneous vector potential wave equation, if points are completely removed from the source, then by which factor does the time varying field & static solution differ?
a. e-jkr
b. ejkr
c. e-jk/r
d. e(jk + r)
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20) Which among the below mentioned magnetic quantities is/are dependent on media/medium?
a. B
b. H
c. Both a and b
d. None of the above
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21) The concept of magnetic vector potential finds its major application in deriving expression of magnetic field intensity especially for ______
a. Real fields
b. Imaginary fields
c. Complex fields
d. None of the above
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22) If J & M are active at the same time, which principle theorem is used for field estimation?
a. Reciprocity
b. Superposition
c. Causality
d. Relativity
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23) A dipole carries r.m.s. current of about 300A across the radiation resistance 2 Ω. What would be the power radiated by an antenna?
a. 90 kW
b. 135 kW
c. 180 kW
d. 200 kW
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24) What is/are the major applications of an infinitesimal dipole that contribute/s to its analysis?
a. Field pattern estimation due to any length of antenna
b. Improvement in radiation resistance by increasing dipole length
c. Both a and b
d. None of the above
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25) What is /are the advantages of using ferrite loops?
A. Increase in Magnetic field intensity
B. Increase in radiation resistance
C. Decrease in Magnetic field intensity
D. Decrease in radiation resistance
a. A & B
b. C & D
c. A & D
d. B & C
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26) In an electrically large loop, an overall length of the loop is equal to ______
a. λ/2
b. λ
c. λ/10
d. λ/50
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27) How do the elements of an active region behave?
a. Inductive
b. Capacitive
c. Resistive
d. None of the above
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28) By how many times is an input impedance of a folded dipole at resonance greater than that of an isolated dipole with same length as one of its sides?
a. 2
b. 3
c. 4
d. 6
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29) Which mode of radiation occurs in an helical antenna due to smaller dimensions of helix as compared to a wavelength?
a. Normal
b. Axial
c. Both a and b
d. None of the above
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30) A rectangular horn antenna operating at 4GHz has the wavelength of 0.075m and gain of about 13dBi. What will be its required capture area?
a. 0.0149 m2
b. 0.0475 m2
c. 0.5521 m2
d. 0.9732 m2
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