Antenna Theory & propagation (EC-604A) MCQ type (marks 1) 1. The angle where the transmitted power has dropped by from the maximum power in the direction at which the antenna is pointing. Electronics and Communication Engineering Questions and Answers. b. Sensor of electromagnetic waves b. Loop a. Curvature of earth Only Reflection A parabolic dish antenna has a diameter of 3m and operates at 46 Hz. b. c. Inversion layer d. Wastage of power in terminating resistor, ANSWER: Maximum radiated power along main axis. a. Which antenna is a properly terminated A Marconi B Rhombic C Dipole D Yagi Uda from TRANSMA ECE151 at National University Manila b. Capacitive d. None of the above. c. Wave is incident in opposite direction of plane of the loop with minimum voltage b. MCQ in Antennas Part 2 as part of the Communications Engineering (EST) Board Exam. a. d. Far-field. d. All of the above. 175. Active region Ranges of frequencies the antenna will radiate effectively. a. Space wave 33)   In ungrounded antennas, if an excitation is applied directly across the base insulator, then on which factor/s would the voltage across the insulator depend? Sea wave propagation a. c. Frequency Acts as a single antenna of twice the height 3. d. All of the above. d. None of the above. d. None of the above, ANSWER: Wave is incident normal to plane of the loop with no induced voltage. 74)   What is the direction of varying orientation of polarized surface wave at the earth surface in a wave tilt mechanism? a. D. By double side band system. a. c. Both a and b Antenna Theory - Antenna Arrays - An antenna, when individually can radiate an amount of energy, in a particular direction, resulting in better transmission, how it would be if few more elements 80)   What is the functioning role of an antenna in receiving mode? 37)   In an electrical circuit,which nature of impedance causes the current & voltages in phase? c. Transducer between guided wave & free space wave Transmission line region Plane to spherical wave 40)   By which name/s is an ionospheric propagation, also known as? c. Along z-axis 1.047 x 106 m/s A. 45 km – 85 km b. Ground wave b. A discone antenna is a radiator whose impedance can be directly matched to what type of coaxial transmission line? d. Triangular. b. (D) Rhombic antenna 8. Low radiation efficiency b. Ionized particles Low d. None of the above, ANSWER: Distance of point from the source (R). Rhombic antenna generally operates on high frequency and very high-frequency ranges. c. Contingent a. The omega match is slightly modified from the ___________. 70)   Linear polarization can be obtained only if the wave consists of ________, a. Ex Moderate b. d. Gyrator. 49)   According to the geometry, how many sterdians are present in a full sphere? - Published on 01 Oct 15 a. a. b. a. c. Both a and b 21)   Which pattern is generated due to plotting of square of amplitude of an electric field? 189. C. By single side band system 160. What is the effective radiated power? a. Ionospheric c. Conformal 8)   Which ionization layer exists during day time & usually vanishes at night due to highest recombination rate? c. Both a and b c. Both a and b It is a measure of how much the antenna concentrates its transmitted microwave power in a given direction. b. 193. 183. d. None of the above. b. c. Sensor d. 190.01 Ω. 170. d. 0.1 cm – 1 cm. 90° & 180° d. 140 km – 200 km, 10)   F2 layer of appleton region acts as a significant reflecting medium for _____ frequency radio waves, a. d. Opposite. c. 0.65 m2 Its impedance by taking into consideration the consequences of other antennas a. Sinusoidal Acts as an antenna array 37. 7.99 dB d. Congruent. It is known as a single directive antenna. Reflection or Scattering c. Defraction Ground wave propagation Also provides professionals with materials for their lectures and practice exams. Is one supplied power from the transmitter, usually through a transmission line. c. Current a. c. Propagation constant b. b. 184. Magnetic field c. Direction of propagation d. All of the above ANSWER: All of the above 2) Which equations are regarded as wave equations in frequency domain for lossless media? a. l ≤ (λ /50) d. Appleton region. 46)   Which conversion mechanism is performed by parabolic reflector antenna? Tilt angle c. Both a and b d. None of the above ANSWER: Tilt angle 66) Which among the following is not a a. a. a. a. Maxwell’s b. Lorentz c. Helmholtz d. Poisson’s ANSWER: Helmholtz 3) If the magnetic field component of a plane … A. c. 90 km – 130 km B. c. 180° & 270° d. Inductive. How does the electric field strength of a standard broadcast station vary with the distance from the antenna? c. 2.50 x 106 m/s a. a. 153. Area Narrowest Antenna array having one active dipole element and two or more parasitic element is known as _______. d. None of the above. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References. 16)   Which among the following defines the angular distance between two points on each side of major lobe especially when the radiation drops to zero? 172. Current The ratio of the signal in the forward direction to the signal in the For a charge with no motion a. Impedance matching device c. Reflective region Impedance for free space is _______. Help me go forward with the same spirit. 60) Consider the following statements about Rhombic antenna 1. c. Amplitude a. d. Hyperbolic. c. Resistive a. Spherical d. Diffracted. One of the following consists of non-resonant antenna… d. 0.9732 m2, Hi! b. Increase in Magnetic field intensity a. a. The fact that the second wire of the folded dipole is folded makes the current on the two conductors of the antenna flow in the _______ direction. b. Read More. 0.0149 m2 a. Widest 190. 28)   In broadside array, all the elements in the array should have similar _______excitation along with similar amplitude excitation for maximum radiation. ______ of the antenna is the ratio of the radiation resistance to the total resistance of the system. 30)   Which mode of propagation is adopted in HF antennas? 59)   What is the far-field position of an electric short dipole? 1) Which among the following exhibits perpendicular nature in TEM wave? Less than b. c. Triangular b. The variation of the slot antenna is _________. b. A pinoybix mcq, quiz and reviewers. The d. All of the above. Marconi antenna is used in many types of mobile communications unit because it allows transmission and receptions in _________. The main difference between half-wave and folded dipole is the __________. Frequency b. 43)   Which among the following plays a primary role in generation of conduction current in an ionosphere due to presence of electric field? b. The tilt angle, θ is approximately equal to 90 minus the angle of major lobe. I am an M.Tech in Electronics & Telecommunication Engineering. D. Reflectivity. 173. c. Neutral molecules b. Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement Subject: Antenna and Wave Propagation 2 Part 2: List for questions and answers of Antenna & wave Propagation Q1. Subscribe to our mailing list and get interesting stuff and updates to your email inbox. b. 164. Along y-axis b. Lorentz 154. It is a very efficient and widely employed antenna for radio communication where enough space necessary for its … 71)   When an electromagnetic wave travels from transmitter to receiver, which factor/s affect/s the propagation level? 38)   Which type of ground wave travels over the earth surface by acquiring direct path through air from transmitting to receiving antennas? Linear If the antenna is receiving of 10^-12 v/m of electric field, magnetic field of 3.2 x 10^-3 A/m at a 5 sq. d. Poisson’s. 6.53 dB b. Phase velocity 29)   Which among the following is regarded as a condition of an ordinary endfire array? m absorbing area, what is the power received? 195. d. Facsimile, 3)   Wavefront is basically a locus of points acquiring similar _______, a. d. Wave equation. 90)   What is/are the major applications of an infinitesimal dipole that contribute/s to its analysis? Calculate the aperture. Distance of point from the source (R) 15)   At which angles does the front to back ratio specify an antenna gain? c. β + (λ/2) a. Horizontal c. Partial reflection & refraction For low and medium frequency antennas which are mounted vertically from the earth’s surface, the effective length is referred to as __________. 12)   According to Webster’s dictionary, what is an antenna? 0.032 m2 4)   In which kind of waveform is the phase velocity defined? a. Spherical 50)   The vector magnetic potential shows the inverse relationship with its ____, a. b. c. Plane angle 5) o parabolic reflectors, corner reflectors o These are high gain antennas usually used in radio The Rhombic Antenna is an equilateral parallelogram shaped antenna. a. 42)   Which mechanism/s is/are likely to occur in mid-frequency operation corresponding to ionospheric region? Tilt angle C. Both a and b D. None of the above Ans: Tilt angle 66. d. All of the above, ANSWER: For a charge oscillating in time motion. Calculate effective absorbing area operating at 106 Hz for a standard half-wave dipole. 186. b. Microstrip 152. b. a. Convergent d. Front to back ratio (FBR), 17)   If an observation point is closely located to the source, then the field is termed as ________, a. b. Regression layer c. Both a and b A dish antenna has a diameter of 2m and operates at 46 Hz, find the antenna gain at 65% efficiency. 182. d. All of the above. inoyBIX educates thousands of reviewers and students a day in preparation for their board examinations. c. Both a and b b. Imaginary fields The major lobes of the directive pattern are those in which the radiation is _______. d. All of the above. Phase 75)   Which layer has the atmospheric conditions exactly opposite to that of standard atmosphere? d. 180° & 360°. 179. c. 123.17 Ω d. All of the above. Is used to increase the current at the base of the antenna, and also to make the current distribution more uniform. a. Which angle of rhombic antenna represents one half of included angle of two legs of one wire? 18)   Which waveform plays a crucial role in determining the radiation pattern of the dipole/wire antennas? a. Linear angle c. For a charge oscillating in time motion 62)   If the elements of a binomial array are separated by λ/4, how many shape patterns are generated with no minor lobes? Source d. All of the above. a. SONAR b. 88)   The concept of magnetic vector potential finds its major application in deriving expression of magnetic field intensity especially for ______, a. d. None of the above, 20)   In flared transmission line, the radiation phenomenon increases due to ________ in flaring, a. d. Phase. Equal to At the moment, Pinoybix has become one of the most trusted engineering review sites helping thousands of aspiring engineers achieve their goals. Equality of directional patterns b. Axial Radiation from an antenna at other angles than the desired direction. c. 10 cm – 1 m An area of radiation which exist between adjacent nulls. c. 33.33 ohm 0° & 180° 158. 199. a. a. 155. a. Aperture A wire several wavelengths in length that is suspended at some height above the earth. b. 68)   Which kind of polarization is provided by helical antennas? Mor-gain_antenna_broch_1977.pdf Mor-gain_antenna_broch_1978.pdf Mosley_Antenna_maintenance_2011.pdf Mosley_Checking_traps_2011.pdf Mosley_Devant_special_user.pdf Mosley_El_Toro_review_1965.pdf Mosley_MCQ b. Divergent Following is the list of multiple choice questions in this brand new series: P d. None of the above. a. Reactive c. Helical C. Decrease in Magnetic field intensity b. a. d. Square. c. Diagonal Normal E-region b. b. Elliptical 191. a. Inward 76)   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? b. Resistive 188. Generally, it has two opposite acute angles. Helical antenna is an antenna which has a helix or spring shape. These antennas have a quite large structure thus is used in applications where the placement of the antenna is not an issue. 20 km – 50 km And, if you really want to know more about me, please visit my "About" Page. It is non resonant 2.It is a broad band antenna 3.It is ideally suited for HF transmission Which of the above are correct? 78)   How is the effect of selective fading reduced? c. Capacitive 198. A a. 65. d. All of the above. c. Magnetic field of earth Reflected 194. Equality of impedances a. d. Voltage. Electric field intensity a. Its polarisation and radiation properties depend on the diameter, pitch, number of turns, wavelength, excitation and spacing between the helical loops. 2)   Which among the following is an application of high frequency? c. l = λ/2 This antenna is a monopole in that it uses a half-wavelength radiator, but is fed at a voltage node rather than current node. b. Rectangular c. Elliptical What is the approximate effective length of an antenna at 10 MHz. Along x-axis a. Inductive a. 96)   A rectangular horn antenna operating at 4GHz has the wavelength of 0.075m and gain of about 13dBi. c. Triangular 1)   What is the wavelength of Super high frequency (SHF) especially used in Radar & satellite communication? c. Circular a. Perpendicular d. 39.77 ohm. 26)   In which kind of array configuration, the element locations must deviate or adjust to some nonplaner surface like an aircraft or missile? b. A [v]) 1, 2, 3 B [ ]) 1, 3 only C [ ]) 2, 3 only A pinoybix mcq, quiz and reviewers. d. Tilt angle. By high carrier reception (λ/50 ) < l ≤ (λ /10) 56)   What is the nature of current distribution over the small dipoles? a. A resistance which accounts for the energy dissipated in the form of heat. 7)   If the path difference of two waves with single source traveling by different paths to arrive at the same point, is λ/2, what would be the phase difference between them? d. Inverter. d. Lens. 167. 0.7883 Ω C. Resistivity Q15. c. Array Decrease 22)   In an electrically small loops, the overall length of the loop is ______ one-tenth of a wavelength. b. Outward b. Vertical b. Shunt 161. b. Spherical to plane wave of ECE P a g e | 6 mounted. If the antenna is not in the exact dimension/measurement, the impedance of the antenna turns to be: 159. In a TV receiver, the linearity can be checked by: (A) VTVM (B) Multimeter (C) Vector gram (D) Pattern generator 9. d. None of the above. a. β x (λ/2) 81)   In radio communication link, what is the shape/nature of waves generated by transmitting antenna? b. Subsurface communication The design ratio of the log-periodic antenna must be _____. d. None of the above. Rhombic antenna is a highly directional broad-band antenna with the greatest radiated or received power along the main axis or longer diagonal. Power factor of impedance d. 3 x 106 m/s. 0.0475 m2 162. Must be horizontally polarized 4. b. d. None of the above, 24)   From the radiation point of view, small loops are _________radiators. a. Spherical Improvement in radiation resistance by increasing dipole length c. Back lobe 1 cm – 10 cm A. Permittivity 91)   What is /are the advantages of using ferrite loops? Induced a. D-region Series Home >> Category >> Electronic Engineering (MCQ) questions & answers >> Antenna & Wave Propagation « Previous Next » Q. b. a. Increase b. Plane 61)   If a linear uniform array consists of 9 isotropic elements separated by λ/4, what would be the directivity of a broadside array in dB? Half power beam width (HPBW) Real fields 65) Which angle of rhombic antenna represents one half of included angle of two legs of one wire? c. Mid 65)   Which angle of rhombic antenna represents one half of included angle of two legs of one wire? A. Ampere’s law 1 m – 10 m a. Radiator a. Reactive near-field region A point where the power field strength is zero. c. Side lobe level (SLL) 27.77 ohm Surface wave c. Reflected 181. 165. ElectronicsPost.com is a participant in the Amazon Services LLC Associates Program, and we get a commission on purchases made through our links. c. Greater than b. a. Ions Learn vocabulary, terms, and more with flashcards, games, and other study tools. Vertical antenna like those used in the AM broadcast and lower frequency armature band rely heavily upon a good __________ for maximum coverage. 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None of the above potentials, what factor of time delay generally! ) Under which conditions of charge does the front to Back ratio specify an antenna in mode! Visit my `` about '' Page reception c. by single side band system by. Consists of non-resonant antenna… 60 ) Consider the following plays a primary role generation! Makes an angle θ = 90° 0.1 cm – 10 cm c. 10 cm c. 10 cm 10. Independent nature of angular field distribution over the small dipoles a gain of Yagi-Uda arrays, what factor time! Est ) Board Exam major application in deriving expression of magnetic vector potential finds major.