Antenna objective questions with answers part1

Q1. serious capacitor is used in transmission line to
(A) reduce line losses
(B) compensate the voltage drop
(C) limit short circuit current
(D) improve load power factor

Q2. The highest modulation frequency typically used in FM broadcast is:
(A) 5kHz
(B) 15kHz
(C) 10kHz
(D) 25kHz

Q3. In radio receivers tube EM84 is used as
(A) magic eye
(B) full wave rectifier
(C) audio amplifier
(D) none of the above

Q4. Troposcatter antenna generally used is:
(A) Parabolic antenna
(B) horn antenna
(C) yagi antenna
(D) helical antenna

Q5. Impedance of a half wave folded dipole antenna is
(A) 100 ohms
(B) 200 ohms
(C) 300 ohms
(D) 400 ohms

Q6. One of the following is not an omnidirectional antenna:
(A) Half-wave dipole
(B) Log-periodic
(C) Discone
(D) Marconi

Q7. The discone antenna is
(A) useful direction finding antenna
(B) used as a radar receiving antenna
(C) circularly polarized like other circular antennas
(D) useful as UHF receiving antennas

Q8. A helical antenna is used for satellite tracking because of its
(A) circular polarization
(B) maneuverability
(C) broad bandwidth
(D) good front-to-back ratio

Q9. Zoning is used with a dielectric antenna in order to
(A) reduce the bulk of the lense
(B) increase the bandwidth of the lens
(C) increase pin-point focusing
(D) correct the curvature of the wave front from a horn that is too short

Q10. Cassegrain feed is used with a parabolic reflector to
(A) increase the gain of the system
(B) increase the bandwidth of the system
(C) reduce the size of the main reflector
(D) allow the feed to be placed at a convenient point

Q11. Top loading is sometimes used with an antenna in order to increase its
(A) effective height
(B) bandwidth
(C) beamwidth
(D) input resistance

Q12. The standard reference antenna for the directive gain is the
(A) infinitesimal dipo le
(B) isotropic antenna
(C) elementary doublet
(D) half-wave dipole

Q13. Which one of the following terms does not apply to the Yagi-Uda array?
(A) Good bandwidth
(B) Parasitic elements
(C) Folded dipole
(D) High gain

Q14. Which one of the following reasons for the use of a ground screen with antennas is not correct:
(A) Impossibility of a good ground connection
(B) Provision of an earth for the antenna
(C) Protection of personnel working underneath
(D) Improvement of the radiation pattern of the antenna

Q15. One of the following is not a reason for the use of an antenna coupler:
(A) To make the antenna look resistive
(B) To provide the output amplifier with the correct load impedance
(C) To discriminate against harmonics
(D) To prevent re-radiation of the local oscillator

Q16. Which of the following reasons is not true for using a counterpoise with antenna?
(A) Impossibility of a good ground connection
(B) Protection of personnel working underground
(C) Provision of an earth for the antenna
(D) Rockiness of the ground

Q17. Which of the following antennas is best excited from a waveguide?
(A) Bicon ical
(B) Horn
(C) Helical
(D) The folded dipole

Q18. Which of the following is very useful as a multiband HF receiving antenna?
(A) conical horn
(B) folded dipole
(C) log periodic
(D) square loop

Q19. Which of the following consists of non-resonant antennas?
(A) The rhombic antenna
(B) The folded dipole
(C) The end-fire array
(D) The broadside array

Q20. An ungrounded antenna near the ground
(A) acts as a single antenna of twice the height
(B) is unlikely to need a ground screen
(C) acts as an antenna array
(D) must be horizontally polarized