Antenna Question & Answers June 5, 2021 By WatElectronics This article lists 100 Antenna MCQs for engineering students. All the Antenna Questions & Answers given below includes solution and link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up their fundamentals on the Antenna topic which is core in Electrical Engineering. An antenna is a metallic device, built by Heinrich Hertz in the year 1888. Its main function is to perform the transmission and reception process of electromagnetic radio waves between a transmitter and a receiver. The transmitter of the antenna converts an electrical signal into electromagnetic signal form and this EM signal propagates in a medium like air or vacuum to the receiver end of the antenna, where at the receiver end the antenna converts the EM wave back to an electrical signal. Antennas are classified into many types based on their structure like wire type antenna, aperture type antenna, classification based in types of frequency like very low or high-frequency type antenna, microwave antenna, etc, function, capacity, dimensions, classification based on directions like an omnidirectional antenna radiates power in a single direction, a vertical antenna radiates vertically, etc. Some of the advantages of the antenna are it increases the strength of the signal, minimizes the usage of power, and provides high gain. Antennas are used in every small or big electronic device or gadget like TV, radios, mobile phones, etc. 1). Transmitting antenna has which of the following parameter as a basic requirement. Side lobes are low Efficiency is high High SNR value Hint 2). Which of the following is the function of the antenna? Converts photons to electrons Coverts electrons to photons Converts electrons to neutrons Both a and b Hint 3). At what condition does wave radiates? When the TEM wave between transmitting and receiving antenna approaches lambda When the TEM wave between transmitting and receiving antenna exceeds lambda When the TEM wave between transmitting and receiving antenna exceeds lamda None of the above Hint 4). The characteristics of an antenna's radiation pattern can be represented in ________ number of ways. 2 3 4 5 Hint 5). Which of the following is the correct statement for isotropic radiation? It is a point source radiator It radiates uniformly in all directions Maintains uniform intensity All the above Hint 6). Isotropic radiation is also known as ________. Omni-directional radiation Bi-directional radiation Tri- directional radiation None of the above Hint 7). What is the shape of isotropic radiation when observed in 3D? Doughnut shaped Figure of Eight Spherical Circle Hint 8). What is the shape of isotropic radiation when observed in 2D? Doughnut shaped Figure of Eight Spherical Circle Hint 9). What is the gain factor of an isotropic radiator in all directions? 1 0 Infinity 0db Hint 10). What is the gain factor (in dB) of an isotropic radiator in all directions? 1 0 Infinity 0db Hint 11). EIRP in an isotropic antenna stands for _________. Effective isotropic radiated power Equivalent isotropic radiation power Entropic isotropic radiated power Equivalent isolated radiated power Hint 12). Which of the following statement is true related to EIRP? The power radiated by an isotropic antenna produces peak power density in the direction of antennas maximum gain The power radiated by an isotropic antenna produces peak power density in the direction of antennas minimum gain The power radiated by an isotropic antenna produces peak power density in the direction of antennas zero gain All the above Hint 13). If the angle of radiation is focused at a direction this will _____ the EIRP with the gain of an antenna. Increases Decreases Remain same 0 Hint 14). Which of the following is an equation for ERP of an isotropic antenna? ERP(dBW) = EIRP (dBW) – 2.15dBi ERP(dBW) = EIRP (dBW) – 3.15dBi ERP(dBW) = EIRP (dBW) + 2.15dBi ERP(dBW) = EIRP (dBW) * 2.15dBi Hint 15). Radiation is plotted graphically in terms of _______. Angular position and radial distance Angular position and Angular distance Distance and radiation Radiation and beam angle Hint 16). Radiation patterns can be represented in terms of _______ types. Field patterns Power patterns Both a and b Direction pattern Hint 17). Which of the following statement is true for field patterns? It is a logarithmic graph plotted against the electric field function and magnetic field function. It is a logarithmic graph plotted against the square of electric field function and magnetic field function. It is a logarithmic graph plotted against the square of the magnitude electric field function and magnetic field function. It is a logarithmic graph plotted against the square of the magnitude of electric field and magnetic field. Hint 18). Which of the following statement is true for power patterns? It is a logarithmic graph plotted against the electric field function and magnetic field function. It is a logarithmic graph plotted against the square of electric field function and magnetic field function. It is a logarithmic graph plotted against the square of the magnitude electric field function and magnetic field function. It is a logarithmic graph plotted against the square of the magnitude of electric field and magnetic field. Hint 19). A 2-D radiation pattern graph contains how many coordinates? 2 3 5 1 Hint 20). Which of the following statement is true related to the major lobe? It is a radiated part that covers maximum area It is a radiated part that covers a minimum area Both a and b It is a radiated part that covers the average area Hint 21). A 3-dimensional radiation pattern graph contains how many coordinates? 3 4 2 1 Hint 22). Which of the following statement is true related to the minor lobe? It is a radiated part that covers maximum area It is a radiated part that covers a minimum area Both a and b It is a radiated part that covers the average area Hint 23). Which of the following statement is true related to the back lobe? It is a radiated part that covers maximum area It is a radiated part that covers a minimum area Both a and b It is exactly opposite to the maximum lobe Hint 24). Which of the following statement is true related to pencil beam pattern? It is a sharp directional pencil-shaped pattern It is a fan shaped beam pattern It is a non uniform beam pattern Hint 25). Which of the following statement is true related to fan beam pattern? It is a sharp directional pencil shaped pattern It is a fan shaped beam pattern It is a non uniform beam pattern It is a uni-directional beam pattern Hint Antenna MCQs with Answers 26). Which of the following statement is true related to shaped beam pattern? It is a sharp directional pencil shaped pattern It is a fan shaped beam pattern It is a non uniform beam pattern It is a uni-directional beam pattern Hint 27). How many ways a beam pattern can be represented in isotropic radiation? 2 4 3 5 Hint 28). An isotropic radiation is __________. It is a point source of radiation It radiates uniformly in all direction It has a uniform intensity All the above Hint 29). Which of the following is the example of an isotropic radiator? Point source All direction source Bi directional source Both a and b Hint 30). Which of the following is the condition for beam area? It is a solid angle through which all power radiated by the antenna would stream if P (Ɵ, φ) maintained maximum over ΩA and was zero apart from that It is a solid angle through which all power radiated by the antenna would stream if P (Ɵ, φ) maintained maximum over ΩA and was unity apart from that It is a solid angle through which all power radiated by the antenna would stream if P (Ɵ, φ) maintained minimum over ΩA and was zero apart from that It is a solid angle through which all power radiated by the antenna would stream if P (Ɵ, φ) maintained minimum over ΩA and was unity apart from that Hint 31). Which of the following is the correct statement of beam angle? It is an angle between half power point of the main lobe It is an angle between power point of the main lobe and side lobe It is an angle between half power point of side lobe None of the above Hint 32). Which of the following is the unit of beam area? Watts Hour Degrees Centimeters Hint 33). Beam efficiency is the ratio between main beam area and _______. Total beam area radiated Minimum beam area Half a beam area None of the above Hint 34). Beam efficiency is termed as ___________. Maximum radiated energy of a beam Minimum losses Both a and b Maximum losses Hint 35). Beam efficiency is mathematically expressed as ________. Main beam area / total solid beam angle Side beam area / total solid beam angle Main beam area / solid beam angle None of the above Hint 36). Antenna can be polarized in __________ ways. 1 2 3 4 Hint 37). On polarizing an antenna which of the following parameters are decided. Beams pattern Transmission polarization Reception polarization All the above Hint 38). Which of the following is true regarding linear polarization? It maintains wave propagation in a single direction It maintains wave propagation in multiple directions It maintains wave propagation in the bi direction None of the above Hint 39). In a linear polarization which of the following parameter relies on the same plane. Electric field vector Magnetic field vector EM vector None of the above Hint 40). Which of the following is true regarding circular polarization? It is polarized circularly It is linearly polarized It is horizontally polarized None of the above Hint 41). Which field vector in circular polarization, is rotated with respect to all coordinated losing orientation? Electric field vector Magnetic field vector EM vector None of the above Hint 42). An example of circular polarization is _______. GPS Radio wave TV signals Mobile communication signals Hint 43). Which of the following is true regarding horizontal polarization? It is polarized circularly It is linearly polarized It is horizontally polarized None of the above Hint 44). Which of the following is the frequency of horizontal polarization? 1 GHz 10 GHz 15 GHz 20 GHz Hint 45). Which of the following is an example of horizontal polarization? GPS Radio wave TV signals Mobile communication signals Hint 46). Horizontal polarization, makes the wave _______ due to reflection of the wave from the earth surface. Strengths Weak Half Zero Hint 47). An example of the vertically polarized wave is ________. GPS Radio wave TV signals Mobile communication signals Hint 48). Beam width is defined as __________. Aperture angle of maximum power radiated Aperture angle of minimum power radiated Aperture angle of zero power radiated Aperture angle of infinite power radiated Hint 49). Which of the following parameters are chosen in beam width? Half power beam width HPBW First null beam width FPBW Full beam width A and B Hint 50). In a Half power beam width HPBW radiation pattern is decreased by ______ % from the main peak beam? 10% 50% 90% 99% Hint Antenna Exam Questions & Answers 51). Half power beam width HPBW is mathematically expressed as ________. 70 * wavelength / diameter 60 * wavelength / diameter 80 * wavelength / diameter 90 * wavelength / diameter Hint 52). Half power beam width HPBW is expressed in terms of _______. Radians Degrees Centimeters Both a and b Hint 53). First null beam width FNBW is the angle between ________. Two tangents of origin of radiation pattern and main beam Two main beams Two side beams None of the above Hint 54). What is the formula of first null beam width? FNBW = 2 HPBW FNBW = 3 HPBW FNBW = HPBW FNBW = 5 HPBW Hint 55). FNBW is expressed in terms of _______. Radians Degrees Centimeters Both a and b Hint 56). Effective length of antenna is used to find ______ parameter of antenna. Polarization efficiency Beam width Beam loss Beam angle Hint 57). Effective length of receiving antenna is defined as the ratio between _______. Receiving antennas open terminal voltage magnitude to field strength wave front magnitude of an incident wave Transmitting antennas open terminal voltage magnitude to field strength wave front magnitude of an incident wave Antennas open terminal voltage magnitude to field strength wave front magnitude of an incident wave None of the above Hint 58). Effective area of receiving antenna is defined as ______. Ratio of the incoming wave front that absorbs most of the power to antennas total area Ratio of the incoming wave front that absorbs a minimum of the power to antennas total area Ratio of incoming wave front to antennas total area None of the above Hint 59). The effective area of an antenna is defined as _______. It is the portion of the received wave front, where some portion gets scattered and some portion gets dissipated It is the portion of the received wave front, where half portion gets scattered and some portion gets dissipated It is the portion of the received wave front, where half portion gets scattered and half portion gets dissipated It is the portion of the received wave front, where complete portion gets scattered and some portion gets dissipated Hint 60). If antenna properties do not change with the operation it is a ______ property. Reciprocity Directivity Polarization Magnetization Hint 61). Which of the following are trans-receiver reciprocity properties? Directional patterns are equal Directivities are equal Effective lengths are equal All the above Hint 62). Antennas use which type of energy wave to communicate information. Electromagnetic wave energy UV energy wave White wave energy Radio wave energy Hint 63). An electromagnetic wave are graphically represented between _____ and _____. Energy and power Energy and frequency Frequency and power Bandwidth and power Hint 64). An electromagnetic wave has how many fields _______. 2 3 4 5 Hint 65). Electric field in EM wave is plotted on ______ axis. X-axis Y-axis Z-axis Either a or b Hint 66). Magnetic field in EM wave is plotted on ______ axis. X-axis Y-axis Z-axis Either a or b Hint 67). Which of the following vector states about EM wave energy per unit time per unit area at any time? Poynting vector Dimensional vector Beam vector None of the above Hint 68). Poynting vector was derived by ____ in _____ year. John Henry Poynting in 1884 Edwin in 1884 Richard 1887 Charles in 1890 Hint 69). Units of Poynting vector is ________. W/m2 W/m m/W wm Hint 70). Instantaneous Poynting vector is mathematically expressed as _______. S = E X H S = E / H S = E S = M Hint 71). Units of Electric field intensity is _______. Volts/meters Volts/meters2 Meters/Volts Hint 72). Units of magnetic field intensity is _______. Amperes/meter Meters/Amperes Amperes meters Amperes Hint 73). Which of the following statement is true in the Poynting vector regarding EM wave? Magnitudes of both electric and magnetic fields are equal Magnitude of the electric field is greater than the magnitude of the magnetic field Magnitude of the electric field is less than the magnitude of the magnetic field Magnitudes of both electric and magnetic fields are zero Hint 74). On which of the antennas of the following base are classified. Physical structure Functionality Length Both a and b Hint 75). Which of the following are the examples of a wire antenna? Dipole antenna Monopole antenna Helix antenna All the above Hint Antenna Interview Questions & Answers 76). Which of the following are the applications of wire antenna? Buildings Ships Automobiles All the above Hint 77). Which of the following are the examples of aperture antennas? Waveguide antenna Horn antenna Both a and b Loop antenna Hint 78). Which of the following are the applications of aperture antenna? Flush mounted applications Air craft applications Space craft All the above Hint 79). Which of the following are the examples of reflector antenna? Parabolic reflectors Corner reflectors Horn antenna Both a and b Hint 80). Which of the following are the applications of reflector antenna? Microwave communication Satellite tracking Radio astronomy All the above Hint 81). Which of the following are the applications of lens antenna? Used in high frequency applications Parabolic reflectors Corner reflectors Horn antenna Hint 82). Which of the following are the examples of lens antenna? Convex plane antenna Concave plane antenna Convex-convex antenna All the above Hint 83). Which of the following are the applications of microstrip antenna? Air-craft Space-craft Cars All the above Hint 84). Which of the following are the examples of microstrip antenna? Circular shaped Rectangular shaped Both a and b Aperture array Hint 85). Which of the following is the application of array antenna? High gain application Radiation control applications Cars Both a and b Hint 86). Which of the following are the examples of array antenna? Yagi-uda Aperture array Slotted wave guide array All the above Hint 87). Half wave dipole antenna is also called as ________. Hertz antenna Frequency antenna Power antenna Voltage antenna Hint 88). What is the range of frequency in which a dipole antenna operates? 33KHz to 300 GHz 3KHz to 300 GHz 30KHz to 300 GHz 31KHz to 300 GHz Hint 89). Which of the following are the advantages of a half wave dipole? Less input impedance Impedance of a transmission line is matched Consumes more power Hint 90). Which of the following is the disadvantage of a full wave dipole antenna? High dissipation of heat More power wastage Gain is zero All the above Hint 91). What is the range of frequency in a short dipole antenna that operates? 33KHz to 300 GHz 3KHz to 30 MHz 30KHz to 300 GHz 31KHz to 300 GHz Hint 92). If the wavelength is bigger than the length of dipole then it is termed as a type of ______ dipole. Infinitesimal dipole Long dipole Short dipole Any of the above Hint 93). What is the radiation pattern of a short dipole in 2D? Elliptical Circular Figure of eight Figure of eight Hint 94). Which of the following are the disadvantages of a short dipole antenna? Low SNR Low radiation Less efficiency All the above Hint 95). Which of the following are the types of long wire antenna? Resonant antenna Non-resonant antenna Both a and b Beam antenna Hint 96). Resonant antenna is _________ in nature. Periodic Aperiodic Both a and b None of the above Hint 97). Non-Resonant antenna is ________ in nature. Periodic Non-periodic Both a and b None of the above Hint 98). Long-wire antennas are used as basic elements in _______ antennas. V-shaped Rhombic antenna Circular shaped Both a or b Hint 99). What is the range of frequency in a V-shaped antenna that operates? 33KHz to 300 GHz 3 to 30 MHz 30KHz to 300 GHz 31KHz to 300 GHz Hint 100). What is the range of frequency in an inverted V-shaped antenna that operates? 33KHz to 300 GHz 3 to 30 MHz 30KHz to 300 GHz 31KHz to 300 GHz Hint 101). A 3-dimensional radiation pattern graph contains how many coordinates? 3 4 2 1 Hint Time is Up! Time's up
