MCQ in Antennas Part 7 | ECE Board Exam

This is the Multiples Choice Questions Part 7 of the Series in Antennas as one of the Communications Engineering topic. 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.

Online Questions and Answers Topic Outline

• MCQ in Basic considerations
• MCQ in Wire Radiators in Space
• MCQ in Isotropic Radiator
• MCQ in Current and Voltage Distributions
• MCQ in Resonant and Non-resonant Antennas
• MCQ in Antenna Terms and Definition
• MCQ in Antenna Gain and Resistance
• MCQ in Bandwidth, Beamwidth and Polarization
• MCQ in Grounded and Ungrounded Antennas
• MCQ in Grounding Systems and Matching Systems
• MCQ in Antenna Types
• MCQ in Directional and Non-directional Antennas
• MCQ in Microwave Antennas
• MCQ in Wideband and Special Purpose Antennas

Continue Practice Exam Test Questions Part 7 of the Series

301. For receive power density of 10 uW/m^2 and a receive antenna with a capture area of 0.2 m^2, determine the captured power.

a. 0.5 uW

b. 2 uW

c. 1 uW

d. 1.5 uW

302. The property of interchangeability for the transmitting and receiving operations is known as ______.

a. efficiency

b. accuracy

c. reciprocity

d. polarization

303. The length of a doublet at 27 MHz is _____.

a. 8.67 ft

b. 17.3 ft

c. 18.2 ft

d. 34.67 ft

304. Refers to the orientation of the electric field radiated from an antenna.

a. efficiency

b. beamwidth

c. polarization

d. accuracy

305. At frequencies below 2 MHz, what type of antenna is usually used?

a. Marconi antenna

b. Hertzian antenna

c. Hertz antenna

d. Elementary doublet

306. The angular separation between two half-power points in the major lobe of the antenna’s plane radiation pattern.

a. bandwidth

b. polarization

c. efficiency

d. beamwidth

307. Hertz antenna are predominantly used with frequencies above

a. 3 MHz

b. 4 MHz

c. 5 MHz

d. 2 MHz

308. Defined as the frequency range over which antenna operation is satisfactory

a. beamwidth

b. channel

c. bandwidth

d. baseband

309. One of the following is not an omnidirectional antenna.

a. Half-wave dipole

b. Log-periodic

c. Discone

d. Marconi

310. The point on the antenna where the transmission line is connected is called _______.

a. center feed

b. end feed

c. feedpoint

d. voltage feed

311. A popular vertical antenna is the _____>

a. collinear

b. dipole

c. ground plane

d. broadside

312. The discone antenna is

a. a useful direction-finding antenna

b. used as a radar receiving antenna

c. circularly polarized with other circular antennas

d. useful as a UHF receiving antenna

313. The feedpoint presents and ac load to the transmission line called

a. antenna output impedance

b. antenna input impedance

c. feedpoint impedance

d. center feed impedance

314. 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

315. The simplest type of antenna.

a. Elementary doublet

b. Half-wave dipole

c. Quarterwave dipole

d. 5/8 wavelength dipole

316. Zoning is used with a dielectric antenna in order to

a. reduce the bulk of the lens

b. increase the bandwidth of the lens

c. permit pin-point focusing

d. correct the curvature of the wavefront from a horn that is too short

317. It is an electrically short dipole

a. short dipole

b. quarterwave dipole

c. half-wave dipole

d. yagi antenna

318. Cassegrain feed is used with 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

319. The half-wave dipole is generally referred to as ______.

a. Yagi antenna

b. Hertzian antenna

c. Marconi antenna

d. Hertz antenna

320. Top loading is sometimes used with an antenna in order to increase its

a. effective height

b. bandwidth

c. beamwidth

d. input capacitance

321. What is the directivity of a Hertz antenna?

a. 1.64

b. 2.18

c. 2.15

d. 1.75

322. The standard reference antenna for the directive gain is the _______.

a. infinitesimal dipole

b. isotropic antenna

c. elementary doublet

d. half-wave dipole

323. An antenna which is one-quarter wavelength long, mounted vertically with the lower end either connected directly to ground or grounded through the antenna coupling network.

a. loop antenna

b. hertzian dipole

c. monopole antenna

d. turnstile antenna

324. An antenna that is circularly polarized is the

a. helical

b. small circular loop

c. parabolic reflector

d. Yagi – Uda

325. It is a wire structure placed below the antenna and erected above the ground.

a. ground plane

b. counterpoise

c. ground lines

d. top hat

326. Which of the following terms does not apply to the Yagi-Uda array?

a. good bandwidth

b. parasitic elements

c. folded dipole

d. high gain

327. It effectively cancels out the capacitance component of the antenna input impedance.

a. ground plane

b. top hat

c. loading coil

d. shunt capacitance

328. Indicate which of the following reasons for the use of an earth mat with antenna is false:

a. impossibility of a good ground conduction

b. provision of an earth for an antenna

c. protection of personnel working underneath

d. improvement of the radiation pattern of the antenna

329. A metallic array that resembles a spoke wheel placed at the top of an antenna, it increases the shunt capacitance to ground reducing the overall antenna capacitance.

a. loading coil

b. top loading

c. series capacitance

d. series inductors

330. Indicate the antenna that is not wideband:

a. discone

b. folded dipole

c. helical

d. marconi

331. It is formed when two or more antenna elements are combined to form a single antenna.

a. antenna elements

b. antenna array

c. driven elements

d. parasitic elements

332. 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 local oscillators

333. It is an individual radiator, such as a half or quarter-wave dipole.

a. antenna element

b. antenna array

c. reflector

d. director

334. Indicate which of the following reasons for using a counterpoise with antennas is false:

a. impossibility of a good ground connection

b. protection of personnel working underneath

c. provision of an earth for the antenna

d. rockiness of the ground itself

335. Type of antenna element that is directly connected to the transmission lines and receives from or is driven by the source.

a. driven array

b. parasitic array

c. driven element

d. parasitic element

336. Which of the following antennas is best excited from a waveguide?

a. biconical

b. horn

c. helical

d. discone

337. Type of antenna element that is not connected to the transmission lines.

a. parasitic array

b. driven array

c. parasitic array

d. parasitic element

338. One of the following is very useful as a multi-band HF receiving antenna. This is the:

a. conical horn

b. folded dipole

c. log-periodic

d. square loop

339. A parasitic element that is longer than the driven element from which it receives energy.

a. driven element

b. director

c. parasitic elements

d. reflector

340. One of the following consists of non-resonant antennas.

a. rhombic antenna

b. folded-dipole antenna

c. end-fire antenna

d. broadside antenna

341. A parasitic element that is shorter than its associated driven element.

a. redirector

b. director

c. reflector

d. parasitic element

342. An ungrounded antenna near the ground.

a. acts as a single antenna near the ground

b. is unlikely to need an earth mat

c. acts as an antenna array

d. must be horizontally polarized

343. It is a non-resonant antenna capable of operating satisfactorily over a relatively wide bandwidth, making it ideally suited for HF transmission.

a. turnstile antenna

b. loop antenna

c. rhombic antenna

d. discone antenna

344. A wide – bandwidth multi-element driven array is the ______.

a. end-fire

b. log-periodic

c. yagi

d. collinear

345. It is a linear array antenna consisting of a dipole and two or more parasitic elements: one reflector and one director.

a. broadside antenna

b. end-fire antenna

c. yagi-uda antenna

d. phased array antenna

346. An antenna which is consists of a cone that is truncated in a piece of circular waveguide.

a. pyramidal horn antenna

b. circular horn antenna

c. rectangular horn antenna

d. cylindrical horn antenna

347. Which antenna has a unidirectional radiation pattern and gain?

a. dipole

b. ground plane

c. yagi

d. collinear

348. An antenna formed by placing two dipoles at right angles to each other, 90 degrees out of phase.

a. discone antenna

b. turnstile antenna

c. bicone antenna

d. 5/8 wavelength antenna

349. The radiation pattern of collinear and a broadside antenna is ________.

a. omnidirectional

b. bidirectional

c. unidirectional

d. clover-leaf shaped

350. What is the bandwidth ratio of log-periodic antenna?

a. 10:1

b. 5:1

c. 20:1

d. 1:10

Questions and Answers in Antennas Series

Following is the list of multiple choice questions in this brand new series:

Complete List of MCQ in Communications Engineering per topic