MCQ in Microwave Communications Part 9 | ECE Board Exam

(Last Updated On: May 10, 2020)

MCQ in Microwave Communications Part 9 | ECE Board Exam

This is the Multiples Choice Questions Part 9 of the Series in Microwave Communications 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.

MCQ Topic Outline included in ECE Board Exam Syllabi

  • MCQ in Basic Principles of Microwave Communications
  • MCQ in Electro-Optics
  • MCQ in Photonics
  • MCQ in Optoelectronics
  • MCQ in Electromagnetics
  • MCQ in Avionics, Aerospace, Navigational and Military Applications
  • MCQ in Medical Electronics
  • MCQ in Cybernetics
  • MCQ in Biometrics

Continue Practice Exam Test Questions Part 9 of the Series

401. What is used to carry RF energy from magnetron to antenna in a radar set?

a) helix

b) parallel wire line

c) coax

d) waveguide

View Answer:

Answer: Option D

Solution:

402. What is the method of illuminating a parabolic reflector with RF?

a) horn

b) cassegrain

c) helix

d) coax

View Answer:

Answer: Option A

Solution:

403. How would a radar reflector be parabolic-shaped

a) circularly

b) vertically

c) horizontally

d) none of these

View Answer:

Answer: Option C

Solution:

404. In what way are radar emissions similar to microwave ovens?

a) can transmit

b) can receive

c) can cook

d) can transceiver

View Answer:

Answer: Option C

Solution:

405. To what tube is a dc keep-alive voltage applied?

a) Oscillator

b) Transmit-Receive Mixer

c) Circulator

d) Isolator

View Answer:

Answer: Option B

Solution:

406. In radar, if the mixer diode burns out, what are replaced?

a) tube

b) mixer

c) antenna

d) diode

View Answer:

Answer: Option D

Solution:

407. What is the cavity between magnetron and mixer cavity called?

a) ATR

b) TR

c) Transmit

d) Receive

View Answer:

Answer: Option A

Solution:

408. Radar receivers use what Ifs

a) 20 MHz and lower

b) 10 MHz and higher

c) 30 MHz or higher

d) 10 MHz and lower

View Answer:

Answer: Option C

Solution:

409. What kind of local oscillators does a radar receiver use?

a) klystron

b) magnetron

c) LSA

d) TWT

View Answer:

Answer: Option A

Solution:

410. What solid-state types might be used as a radar receiver?

a) Gunn diode

b) Tunnel diode

c) Hot carrier diode

d) Step recovery diode

View Answer:

Answer: Option B

Solution:

411. What does an ATR tube aid?

a) transmitting

b) receiving

c) both transmitting and receiving

d) neither transmitting and receiving

View Answer:

Answer: Option B

Solution:

412. To what is the AFC voltage applied in a klystron?

a) cathode

b) grid

c) plate

d) any of these

View Answer:

Answer: Option C

Solution:

413. Sea return is the control that desentisizes a radar receiver for _____

a) 5 – 10 microseconds

b) 15 – 20 microseconds

c) 10 – 15 microseconds

d) 20 – 25 microseconds

View Answer:

Answer: Option C

Solution:

414. In radars, how is blooming prevented?

a) limit modulation

b) video signal

c) limit the carrier signal

d) limit the audio signal

View Answer:

Answer: Option D

Solution:

415. How is brilliance controlled in radars?

a) audio gain

b) IF gain

c) RF gain

d) video gain

View Answer:

Answer: Option D

Solution:

416. How is sensitivity limited in radars?

a) RF gain

b) video gain

c) audio gain

d) IF gain

View Answer:

Answer: Option D

Solution:

417. How much intensifying pulse is used in radars?

a) Just enough to produce light flicker on screen

b) should be high to produce light flicker on screen

c) should be low to produce light flicker on screen

d) any amount of intensifying pulse will do

View Answer:

Answer: Option A

Solution:

418. If echo signals are developed as negative pulses, to what part of the CRT would they be fed in radar?

a) anode

b) grid

c) cathode

d) 2nd grid

View Answer:

Answer: Option C

Solution:

419. What starts the range-marker circuit ringing in radars?

a) intensifying pulse

b) IF gain

c) AC signal

d) Carrier signal

View Answer:

Answer: Option A

Solution:

420. Why is a selsyn pair not too successful for radar antenna synchronization?

a) constant lead angle

b) variable lag angle

c) constant lag angle

d) variable lead angle

View Answer:

Answer: Option B

Solution:

421. What is fed to the rotor of a selsyn motor?

a) power-line AC

b) DC source

c) A pulsating DC

d) None

View Answer:

Answer: Option A

Solution:

422. What is fed to the rotor selsyn generator?

a) none

b) power-line AC

c) DC source

d) A pulsating DC

View Answer:

Answer: Option B

Solution:

423. What is fed to a control transformer rotor?

a) A pulsating DC

b) power-line AC

c) DC source

d) none

View Answer:

Answer: Option D

Solution:

424. What is used to indicate the bow of the ship on the CRT?

a) tail flash

b) body flash

c) heading flash

d) none

View Answer:

Answer: Option C

Solution:

425. When is an echo box used on ships?

a) testing only

b) direction finding

c) auto alarm

d) ship detection

View Answer:

Answer: Option A

Solution:

426. What qualification must a person have before he is eligible to make repairs to a radar set?

a) NTC endorsement

b) repair license

c) repair endorsement

d) radar endorsement

View Answer:

Answer: Option D

Solution:

427. What is the advantage of using Doppler radar?

a) shows only moving target

b) shows stationary target

c) shows both moving and stationary target

d) produce blips with stationary targets

View Answer:

Answer: Option A

Solution:

428. How would Doppler radar give speed indications?

a) adjust output burst

b) correct RF carrier output

c) switch amplitude detector

d) calibrate discriminator output

View Answer:

Answer: Option D

Solution:

429. What is another application of Doppler radar?

a) distance between radar and stationary target

b) ground speed indicator

c) ground missile indicator

d) enemy base station

View Answer:

Answer: Option B

Solution:

430. Why are signal nulls used in Radio Direction Finders work?

a) sharper than maximums

b) sharper than minimums

c) duller than maximums

d) duller than minimums

View Answer:

Answer: Option A

Solution:

431. How many are signal nulls in one loop rotation Radio Direction Finders?

a) 3

b) 4

c) 5

d) 2

View Answer:

Answer: Option D

Solution:

432. Under what conditions do the horizontal portions of a loop pick up difference currents in RDF?

a) ground waves

b) sky waves

c) space waves

d) direct waves

View Answer:

Answer: Option B

Solution:

433. The method of balancing a loop used in RDF?

a) Capacitor to ground

b) Capacitor to sense antenna

c) Sense antenna to one side of loop

d) Any of these

View Answer:

Answer: Option D

Solution:

434. For what are unidirectional readings used in loops for RDF?

a) resolve a 180 degrees ambiguity

b) resolve a 90 degrees ambiguity

c) resolve a 360 degrees ambiguity

d) resolve a 270 degrees ambiguity

View Answer:

Answer: Option A

Solution:

435. What kind of antenna is a sense antenna used in RDF?

a) circular

b) vertical

c) horizontal

d) any of these

View Answer:

Answer: Option B

Solution:

436. In RDF, what happens to a radio wave path as it moves outward across a coastline as less than 90 degrees?

a) bends away from the shore

b) travels along the shore

c) bends towards shore

d) travels across the shore

View Answer:

Answer: Option C

Solution:

437. What is the result of antenna effect in RDF?

a) rotated 90 degrees

b) nulls shift

c) decreases land effect

d) coastline refraction

View Answer:

Answer: Option B

Solution:

438. What is the result of re-radiation of signals in RDF?

a) great circle error

b) non-opposite minimums

c) polarization errors

d) nulls shifted

View Answer:

Answer: Option D

Solution:

439. What causes night effect in direction finding?

a) ground plus space wave

b) sky plus space wave

c) ground plus sky waves

d) ground wave alone

View Answer:

Answer: Option C

Solution:

440. At what time of the day is direction finder bearings least accurate

a) sunset

b) sunrise

c) mid-day

d) sunset and sunrise

View Answer:

Answer: Option D

Solution:

441. At what angles are quadrantal errors maximum in direction finding

a) 45 degrees

b) 90 degrees

c) 180 degrees

d) 270 degrees

View Answer:

Answer: Option A

Solution:

442. How are quadrantal errors corrected?

a) 330 degrees

b) 360 degrees

c) 315 degrees

d) 215 degrees

View Answer:

Answer: Option C

Solution:

443. How is it that none of the 120-550 kHz ADF circuits are tuned to the desired station?

a) narrowband amplifiers

b) broadband amplifiers

c) IF amplifiers

d) Mixers

View Answer:

Answer: Option B

Solution:

444. What is the only hand-tuned circuit in the ADF?

a) 3125-kHz signal local oscillator

b) 4125-kHz signal local oscillator

c) 2182-kHz signal local oscillator

d) 2230-kHz signal local oscillator

View Answer:

Answer: Option C

Solution:

445. What forms the error signal that actuates the ADF servo-motor?

a) 75-Hz carrier

b) 114-Hz carrier

c) 114-Hz sideband

d) 75-Hz sideband

View Answer:

Answer: Option D

Solution:

446. Which ADF antenna is used for manual operation?

a) parabolic antenna

b) loop antenna

c) half-wave dipole

d) helical antenna

View Answer:

Answer: Option B

Solution:

447. Which ADF antenna is used for simple receive operation?

a) loop antenna

b) sense antenna

c) quarter wave antenna

d) parabolic antenna

View Answer:

Answer: Option B

Solution:

448. What is heard by earphones in the ADF?

a) 3 kHz beat

b) 1 kHz beat

c) 2 kHz beat

d) 5 kHz beat

View Answer:

Answer: Option B

Solution:

449. If two bearing are determined from a radio beacon or station over a period of a few minutes, what else must be known to determine the ship’s position?

a) speed

b) elapses time

c) ship’s course

d) any of these

View Answer:

Answer: Option D

Solution:

450. What important point regarding-loop RDF system maintenance?

a) insulation at top of loop

b) clean moving contacts

c) oil bearing of loop

d) any of these

View Answer:

Answer: Option D

Solution:

Questions and Answers in Microwave Communications and Principles Series

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

MCQ in Microwave Communications
PART 1: MCQ from Number 1 – 50                        Answer key: PART 1
PART 2: MCQ from Number 51 – 100                   Answer key: PART 2
PART 3: MCQ from Number 101 – 150                 Answer key: PART 3
PART 4: MCQ from Number 151 – 200                 Answer key: PART 4
PART 5: MCQ from Number 201 – 250                 Answer key: PART 5
PART 6: MCQ from Number 251 – 300                 Answer key: PART 6
PART 7: MCQ from Number 301 – 350                 Answer key: PART 7
PART 8: MCQ from Number 351 – 400                 Answer key: PART 8
PART 9: MCQs from Number 401 – 450                 Answer key: PART 9
PART 10: MCQs from Number 451 – 500                 Answer key: PART 10

Complete List of MCQ in Communications Engineering per topic

DOWNLOAD PDF / PRINT
Print Friendly, PDF & Email
Please do Subscribe on YouTube!

P inoyBIX educates thousands of reviewers and students a day in preparation for their board examinations. Also provides professionals with materials for their lectures and practice exams. Help me go forward with the same spirit.

“Will you subscribe today via YOUTUBE?”

Subscribe

Add Comment

PinoyBIX Engineering. © 2014-2020 All Rights Reserved | How to Donate? | Follow me on Blogarama DMCA.com Protection Status

Math Solution

Advanced Math problem age work mixture digit motion Analytic Geometry 01 problem Analytic Geometry 02 problem clock variation progression misc Combination problem Differential Calculus 01 Problem Differential Calculus 02 Problem Differential Equations Problem Fundamentals in Algebra Fundamentals in Algebra Problem Integral Calculus problem Permutation problem Plane Geometry problem Plane Trigonometry problem Probability problem quadratic equation binomial theorem logarithms Solid Geometry problem Spherical Trigonometry problem System of Numbers Problem Venn Diagram Problem

Questions and Answers in Mathematics

Advanced Math Age Work Mixture Digit Motion Algebra and General Mathematics Analytic Geometry 01 Analytic Geometry 02 Calculus Clock Variation Progression Misc Differential Calculus 01 Differential Calculus 02 Differential Equations Engineering Mathematics Geometry Integral Calculus Plane Geometry Plane Trigonometry Probability and Statistics Quadratic Equation Binomial Theorem Logarithms Solid Geometry Spherical Trigonometry System of Numbers Trigonometry

video

Pre-board in Electronics Engineering

Answers Pre-board in Electronics Engineering - Answers

Questions and Answers

Basic Television - Grob TV Boylestad Questions and Answers Computer Principles Electrical Circuit Electricity and Magnetism Fundamentals Electronic Circuits Floyd Questions and Answers Floyd Self-test Gibilisco Questions and Answers Grob Questions and Answers Industrial Electronics Principles and Applications Malvino Questions and Answers Microelectronics Power Generators / Sources / Principles and Applications Solid State Devices Tests and Measurements Vacuum Tubes

Pre-board in Communications Engineering

Answers

Questions and Answers

Acoustics Antennas Blake Questions and Answers Broadcasting and Cable TV System Digital Communication Networks Forouzan Frenzel Self-test Kennedy Questions and Answers Microwave Communications Miscellaneous Questions in Communications Modulation Navigational Aids and Radar Systems Noise Optical Fiber Communications Radiation and Wave Propagation Satellite Communications Transmission Fundamentals Wire and Wireless Communications

GEAS Solution

Dynamics problem Economics problem Physics problem Statics problem Strength problem Thermodynamics problem

Pre-board in GEAS

Questions and Answers in GEAS

Engineering Economics Engineering Laws and Ethics Engineering Management Engineering Materials Engineering Mechanics General Chemistry Giancoli Physics Physics Strength of Materials Thermodynamics
Online Tool: Electrical Charge Conversions
Online Tool: Electrical Charge Conversions
Online Tool: Color Code Conversions
Online Tool: Color Code Conversions
Online Tool: Weight Measurement Conversions
Online Tool: Weight Measurement Conversions
Online Tool: Temperature Measurement Conversions
Online Tool: Temperature Measurement Conversions