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Antenna Question & Answers

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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.
HintTransmitting antenna has a high gain and efficiency parameter as a basic requirement.
2). Which of the following is the function of the antenna?
HintThe function of the antenna converts electrons to photons during receiving and photons to electrons while transmission.
3). At what condition does wave radiates?
HintTransmitter radiates wave when the TEM wave between transmitting and receiving antenna approaches lambda.
4). The characteristics of an antenna's radiation pattern can be represented in ________ number of ways.
HintThe characteristics of an antenna's radiation pattern can be represented in 3 number of ways. Ɵ, ϕ, r component.
5). Which of the following is the correct statement for isotropic radiation?
HintIsotropic radiation refers to a point source radiator, that radiates uniformly in all directions maintaining uniform intensity.
6). Isotropic radiation is also known as ________.
HintIsotropic radiation is also known as Omni-directional radiation.
7). What is the shape of isotropic radiation when observed in 3D?
HintThe shape of isotropic radiation when observed in 3D is Doughnut in shape.
8). What is the shape of isotropic radiation when observed in 2D?
HintThe shape of isotropic radiation when observed in 2D is Figure of Eight in shape.
9). What is the gain factor of an isotropic radiator in all directions?
HintThe gain factor of an isotropic radiator in all directions is the “1” unity gain factor.
10). What is the gain factor (in dB) of an isotropic radiator in all directions?
HintThe gain factor (in dB) of an isotropic radiator in all directions is 0 dB.
11). EIRP in an isotropic antenna stands for _________.
HintEIRP is an isotropic antenna that stands for Effective isotropic radiated power.
12). Which of the following statement is true related to EIRP?
HintEIRP stands for Equivalent isotropic radiated power, is the power radiated by an isotropic antenna that produces peak power density in the direction of antennas maximum gain.
13). If the angle of radiation is focused at a direction this will _____ the EIRP with the gain of an antenna.
HintIf the angle of radiation is focussed at a direction this will increases the EIRP with the gain of an antenna.
14). Which of the following is an equation for ERP of an isotropic antenna?
HintThe equation for ERP of an isotropic antenna is ERP(dBW) = EIRP (dBW) – 2.15dBi.
15). Radiation is plotted graphically in terms of _______.
HintRadiation is plotted graphically in terms of angular position and radial distance.
16). Radiation patterns can be represented in terms of _______ types.
HintRadiation patterns can be represented in terms of either field patterns or power pattern types.
17). Which of the following statement is true for field patterns?
HintA field pattern is a logarithmic graph plotted against the electric field function and magnetic field function.
18). Which of the following statement is true for power patterns?
HintPower pattern is a logarithmic graph plotted against the square of the magnitude of electric field and magnetic field.
19). A 2-D radiation pattern graph contains how many coordinates?
HintA 2-D radiation pattern graph x and y coordinate. Where the x-axis is represented as H-plane and the y-axis is represented as a V plane.
20). Which of the following statement is true related to the major lobe?
HintIt is a radiated part that covers the maximum area, containing maximum radiated energy.
21). A 3-dimensional radiation pattern graph contains how many coordinates?
HintA 3-dimensional radiation pattern graph is represented in terms of r, Ɵ, ϕ coordinates.
22). Which of the following statement is true related to the minor lobe?
HintIt is a radiated part that covers a minimum area, containing minimum radiated energy.
23). Which of the following statement is true related to the back lobe?
HintA back lobe is exactly opposite to a maximum lobe, where the amount of energy is wasted here.
24). Which of the following statement is true related to pencil beam pattern?
HintA pencil beam is a sharp directional pencil-shaped pattern.
25). Which of the following statement is true related to fan beam pattern?
HintA Fan beam It is a fan-shaped beam pattern.

Antenna MCQs with Answers

26). Which of the following statement is true related to shaped beam pattern?
HintA shaped beam pattern is a non-uniform beam pattern.
27). How many ways a beam pattern can be represented in isotropic radiation?
HintA beam pattern can be represented in 4 ways namely Omnidirectional pattern, pencil beam pattern, fan-beam pattern, shaped beam pattern in isotropic radiation.
28). An isotropic radiation is __________.
HintAn isotropic radiation is a point source radiation, in all directions uniformly maintaining uniform intensity irrespective of the direction of measurement.
29). Which of the following is the example of an isotropic radiator?
HintAn example of an isotropic radiator is a point source radiator.
30). Which of the following is the condition for beam area?
HintA beam area 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.
31). Which of the following is the correct statement of beam angle?
HintA beam angle is an angle between half powerpoint of the main lobe.
32). Which of the following is the unit of beam area?
HintThe unit of beam area is watts.
33). Beam efficiency is the ratio between main beam area and _______.
HintBeam efficiency is the ratio between the main beam area and the total beam area radiated.
34). Beam efficiency is termed as ___________.
HintBeam efficiency is termed as maximum radiated energy of beam maintaining minimum losses.
35). Beam efficiency is mathematically expressed as ________.
HintBeam efficiency is mathematically expressed as the Main beam area / total solid beam angle.
36). Antenna can be polarized in __________ ways.
HintAn antenna can be polarized in any of 2 ways, like linearly or circularly.
37). On polarizing an antenna which of the following parameters are decided.
HintAn antenna polarization decides beams pattern, transmission, and reception polarization.
38). Which of the following is true regarding linear polarization?
HintA linear polarization maintains wave propagation in a single direction.
39). In a linear polarization which of the following parameter relies on the same plane.
HintIn linear polarization, an Electric field vector relies on the same plane.
40). Which of the following is true regarding circular polarization?
HintA circular polarization polarises a wave circularly.
41). Which field vector in circular polarization, is rotated with respect to all coordinated losing orientation?
HintIn circular polarization, the Electric field vector is rotated with respect to all coordinated losing.
42). An example of circular polarization is _______.
HintAn example of circular polarization is GPS.
43). Which of the following is true regarding horizontal polarization?
HintA horizontal polarization polarises the wave horizontally.
44). Which of the following is the frequency of horizontal polarization?
HintThe frequency of horizontal polarization is 1GHz.
45). Which of the following is an example of horizontal polarization?
HintAn example of horizontal polarization is TV signals.
46). Horizontal polarization, makes the wave _______ due to reflection of the wave from the earth surface.
HintHorizontal polarization makes the wave weak due to the reflection of a wave from the earth's surface.
47). An example of the vertically polarized wave is ________.
HintAn example of a vertically polarized wave is mobile communication signals.
48). Beam width is defined as __________.
HintBeamwidth is the Aperture angle of maximum power radiated.
49). Which of the following parameters are chosen in beam width?
HintThe parameters are chosen in beamwidth are half-power beamwidth HPBW and First null beamwidth FPBW.
50). In a Half power beam width HPBW radiation pattern is decreased by ______ % from the main peak beam?
HintA Half power beamwidth HPBW radiation pattern is decreased by 50 % from the main peak beam.

Antenna Exam Questions & Answers

51). Half power beam width HPBW is mathematically expressed as ________.
HintHalf power beamwidth HPBW is mathematically expressed as 70 * wavelength/diameter.
52). Half power beam width HPBW is expressed in terms of _______.
HintHalf-power beamwidth HPBW is expressed in terms of radians or degrees.
53). First null beam width FNBW is the angle between ________.
HintThe first null beamwidth FNBW is the angle between the two tangents of origin of radiation pattern and main beam.
54). What is the formula of first null beam width?
HintThe formula of the first null beam width is given as FNBW = 2 HPBW.
55). FNBW is expressed in terms of _______.
HintFNBW is expressed in terms of radians and degrees.
56). Effective length of antenna is used to find ______ parameter of antenna.
HintThe effective length of the antenna is used to find the polarization efficiency parameter of an antenna.
57). Effective length of receiving antenna is defined as the ratio between _______.
HintThe effective length of receiving antenna is defined as a receiving antenna's open terminal voltage magnitude to field strength wavefront magnitude of an incident wave.
58). Effective area of receiving antenna is defined as ______.
HintThe effective area of receiving antenna is defined as the ratio of the incoming wavefront that absorbs most of the power to the antenna's total area.
59). The effective area of an antenna is defined as _______.
HintThe effective area of an antenna is defined as the portion of the received wave front, where some portion gets scattered and some portion gets dissipated.
60). If antenna properties do not change with the operation it is a ______ property.
HintIf antennas properties do not change with the operation it is a Reciprocity property.
61). Which of the following are trans-receiver reciprocity properties?
HintThe reciprocity properties of a trans-receiver are Directional patterns are equal, Directivities are equal, Effective lengths are equal.
62). Antennas use which type of energy wave to communicate information.
HintAntennas use Electromagnetic wave energy type of energy wave to communicate information.
63). An electromagnetic wave are graphically represented between _____ and _____.
HintAn electromagnetic wave is graphically represented between Energy and power.
64). An electromagnetic wave has how many fields _______.
HintAn electromagnetic wave has 2 fields, namely electric field, and magnetic field.
65). Electric field in EM wave is plotted on ______ axis.
HintAn electric field in the EM wave is plotted on the X-axis.
66). Magnetic field in EM wave is plotted on ______ axis.
HintThe magnetic field in the EM wave is plotted on the Y-axis.
67). Which of the following vector states about EM wave energy per unit time per unit area at any time?
HintPoynting vector states about EM wave energy per unit time per unit area at any time.
68). Poynting vector was derived by ____ in _____ year.
HintPoynting vector was derived by John Henry Poynting in 1884 year.
69). Units of Poynting vector is ________.
HintUnits of the Poynting vector is W/m2.
70). Instantaneous Poynting vector is mathematically expressed as _______.
HintInstantaneous Poynting vector is mathematically expressed as S = E X H.
71). Units of Electric field intensity is _______.
HintThe Unit of Electric field intensity is V/m.
72). Units of magnetic field intensity is _______.
HintThe unit of magnetic field intensity is Amperes/meter.
73). Which of the following statement is true in the Poynting vector regarding EM wave?
HintIn the Poynting vector Magnitude of the electric field is greater than the magnitude of the magnetic field.
74). On which of the antennas of the following base are classified.
HintAntennas are classified based on their physical structure and functionality.
75). Which of the following are the examples of a wire antenna?
HintExamples of Wire antenna are Dipole antenna, Monopole antenna, Helix antenna, and loop antenna.

Antenna Interview Questions & Answers

76). Which of the following are the applications of wire antenna?
HintThe applications of wire antenna are Buildings, Ships, and Automobiles.
77). Which of the following are the examples of aperture antennas?
HintExamples of aperture antennas are waveguide antenna and horn antenna.
78). Which of the following are the applications of aperture antenna?
HintThe applications of aperture antenna are Flush-mounted applications, Aircraft applications, Spacecraft.
79). Which of the following are the examples of reflector antenna?
HintExamples of reflector antennas are Parabolic reflectors, Corner reflectors.
80). Which of the following are the applications of reflector antenna?
HintThe applications of reflector antenna are Microwave communication, Satellite tracking, and Radio astronomy.
81). Which of the following are the applications of lens antenna?
HintThe applications of lens antenna are - used in high-frequency applications.
82). Which of the following are the examples of lens antenna?
HintExamples of lens antennas are the Convex plane antenna, Concave plane antenna, and Convex-convex antenna.
83). Which of the following are the applications of microstrip antenna?
HintThe applications of microstrip antenna are Air-craft, Space-craft, Cars, mobile phones, etc.
84). Which of the following are the examples of microstrip antenna?
HintExamples of microstrip antennas are circular-shaped and rectangular-shaped antennas.
85). Which of the following is the application of array antenna?
HintExamples of microstrip antenna are High gain application and Radiation control applications.
86). Which of the following are the examples of array antenna?
HintThe examples of array antenna Yagi-uda, Aperture array, and Slotted waveguide array.
87). Half wave dipole antenna is also called as ________.
HintThe half-wave dipole antenna is also called a hertz antenna.
88). What is the range of frequency in which a dipole antenna operates?
HintThe range of frequency in a dipole antenna operates at 3KHz to 300 GHz.
89). Which of the following are the advantages of a half wave dipole?
HintAre the advantages of a half-wave dipole are the Impedance of the transmission line is matched.
90). Which of the following is the disadvantage of a full wave dipole antenna?
HintThe disadvantage of a full-wave dipole antenna is it has high dissipation of heat, more power is wasted during transmission, and the gain of the antenna is zero.
91). What is the range of frequency in a short dipole antenna that operates?
HintThe range of frequency in a short dipole antenna operates is 3KHz to 30 MHz.
92). If the wavelength is bigger than the length of dipole then it is termed as a type of ______ dipole.
HintIf the wavelength is bigger than the length of the dipole then it is termed a type of Infinitesimal dipole.
93). What is the radiation pattern of a short dipole in 2D?
HintThe radiation pattern of a short dipole in 2D is a figure of eight.
94). Which of the following are the disadvantages of a short dipole antenna?
HintThe disadvantages of a short dipole antenna are Low SNR, Low radiation, Less efficiency.
95). Which of the following are the types of long wire antenna?
HintLong wire antenna is classified into 2 types, they are resonant antenna and non-resonant antenna.
96). Resonant antenna is _________ in nature.
HintA resonant antenna is periodic in nature.
97). Non-Resonant antenna is ________ in nature.
HintA non-resonant antenna is non-periodic in nature.
98). Long-wire antennas are used as basic elements in _______ antennas.
HintLong-wire antennas are used as basic elements in either a V-shaped antenna or a rhombic Antenna.
99). What is the range of frequency in a V-shaped antenna that operates?
HintThe range of frequency in a V-shaped antenna operates at 3 to 30 MHz.
100). What is the range of frequency in an inverted V-shaped antenna that operates?
HintThe range of frequency in an inverted V-shaped antenna operates from 3 to 30 MHz.
101). A 3-dimensional radiation pattern graph contains how many coordinates?
HintA 3-dimensional radiation pattern graph is represented in terms of r, Ɵ, ϕ coordinates.

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