# Horn Antenna MCQ

## Horn Antenna MCQ

Horn Antenna MCQ, MCQ on Horn Antenna, Multiple Choice Questions on Horn Antenna, Cone Antenna MCQ, Antenna Based MCQ, Engineering MCQ

Antenna Fundamental Parameters MCQ

### Objective Type Questions

Q.1. Directivity of the horn antenna is high because

• It produces a uniform phase-front with a larger aperture
• It produces a uniform phase-front with a narrower aperture
• It is made by heavy material
• None of the above

Answer: It produces a uniform phase-front with a larger aperture

Q.2. Relation between axial-length of the horn antenna and its aperture is

• Axial-length (L) is inversely proportional to the square of aperture area.
• Axial-length (L) is proportional to square of aperture area.
• Aperture area is proportional to the axial-length.
• None of the above

Answer: Axial-length (L) is proportional to square of aperture area.

Q.3. Choose the most appropriate one: “The typical value of path-difference for the optimum performance of the horn antenna is

• Plane horn, δ = 0.25
• Conical horn, δ = 0.32
• H-plane horn δ = 0.40
• All of the above

Q.4. What will be the largest flare angle for which, δ = 0.25λ and axial-length is 10λ

• 34°
• 25.4°
• 23°
• 45°

Q.5. Very large flare angle (θ) results in the

• Decreased directivity
• Decreased gain
• Increased directivity
• Increased gain

Q.6. The optimum path difference for E-plane horn antenna is

• δ ≤ 0.25λ
• δ ≥ 0.25λ
• δ = 0.25λ
• None of these

Q.7. The path difference for H-plane horn is even δ ≥ 0.25λ, because

• Fields become zero at the horn edge
• Fields go infinite at the horn edge
• Fields become constant at the horn edge
• None of the above

Answer: Fields become zero at the horn edge

Q.8. What is approximate maximum power gain of an optimum horn antenna with a square aperture on a side?

• 39 dBi
• 29 dBi
• 56 dBi
• None of these

Q.9. The required aperture area for an optimum reflector horn antenna operating at 2 GHz with 12 dBi gain.

• 34.56 cm2
• 34.56 cm2
• 40.24 cm2
• 47.5 cm2

• Flaring in the direction of electric field vector (E-plane)
• Flaring in the direction of magnetic field vector (H-plane)
• Flaring in the direction of both electric field vectors (EH plane)
• All are correct.

Q.11. Horn antenna function is based on

• The principle of equality of path
• Huygens principle
• Both principle of equality of path and Huygens principle
• The Maxwell principle

Answer: Both principle of equality of path and Huygens principle

Q.12. The region existing close to the mouth of the horn antenna is

• Far-field region
• Near-field region
• Quasi-static region
• Electrostatic region

Q.13. Very large flare-angle (θ) results in

• Increased beam width
• Decreased directivity
• Decreased gain
• Both Increased beam width and Decreased directivity

Answer: Both Increased beam width and Decreased directivity

Q.14. In practice flare angle varies between 15° and 40°, and the corresponding value of beam width

• 66°
• 166°
• 100°
• 120°

Q.15. The directivity of pyramidal/conical horn antennas is ________ the E-plane/H-plane horn antennas

• More than
• Less than
• Equal to
• None of these

Q.16. The bandwidth of the horn antenna is greater than that of the parabolic reflector antenna because there are no involvements of resonant elements. That is why its directivity is _________ to/than that of parabolic reflector.

• More than
• Less than
• Equal to
• None of these

Q.17. For the standard horn antenna with good performance, the level of cross-polarization should be below co-polarization:

• 30 dB
• 50 dB
• 10 dB
• None of these

Q.18. The bandwidth of a bi-conical antenna can be increased by

• Increasing its cone angle
• Decreasing its cone angle
• Increasing its arms lengths
• Decreasing its cone angle

Q.19. A single cone antenna with 90° angle offers an input resistance of about

• 50 Ω
• 150 Ω
• 100 Ω
• 60 Ω

Q.20. Select the correct statement:

• V-antenna has a bi-directional pattern and narrow bandwidth
• V-antenna has a uni-directional pattern and narrow bandwidth
• V-antenna has a uni-directional pattern and wide bandwidth
• V-antenna has a bi-directional pattern and wide bandwidth

Answer: V-antenna has a bi-directional pattern and narrow bandwidth

Q.21. Which is not a property of a bi-conical V antenna?

• Constant impedance characteristics
• Uni-directional pattern
• Wide bandwidth
• Large beam-width

Q.22. Which is not a property of curved bi-conical V antenna

• Constant impedance characteristics
• Uni-directional pattern
• Wide bandwidth
• None of the above

Q.23. What will be the directivity of a conical horn antenna of radius 2.3 cm at λ = 1.2 m?

• –20.53 dB
• –34 dB
• 50 dB
• 67 dB

Q.24. What is the required aperture area for an optimum rectangular horn operating at 3 GHz with 12 dBi directivity

• 0.0211 m2
• 1.34 m2
• 0.050 m2
• 1.67 m2