Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Transmission Lines and Antennas: A Comprehensive Guide with Questions and Answers, Exams of Electrical and Electronics Engineering

A comprehensive overview of transmission lines and antennas, covering key concepts, characteristics, and applications. It includes a series of questions and answers that test understanding of the material, making it a valuable resource for students and professionals in the field of electrical engineering.

Typology: Exams

2024/2025

Available from 02/11/2025

essay-writers
essay-writers 🇺🇸

3.8

(91)

1.9K documents

1 / 16

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
ATT TEST 12 LATEST TEST 2025 (COMPLETE TEST) |
ALL QUESTIONS AND CORRECT ANSWERS |
GRADED A+ | VERIFIED ANSWERS | NEWEST
VERSION
What develops the characteristic impedance of the transmission line cable?
---------CORRECT ANSWER-----------------Combination of the resistance,
capacitance, and inductance of the cable
What needs to happen to transfer the maximum amount of energy from the
source to the load? ---------CORRECT ANSWER-----------------Impedance
must be matched or equal between input and output
What is the result of mismatched impedance? ---------CORRECT
ANSWER-----------------Damaging standing waves reflected back toward the
source, causes loss of power
What is skin effect? ---------CORRECT ANSWER-----------------High
frequency current that has a tendency to flow to the outside of the
conductor
What is induction loss? ---------CORRECT ANSWER-----------------When
mag field expands and contracts inducing voltage and current into
conducting material near the transmission lines
What is radiation loss? ---------CORRECT ANSWER-----------------Loss to
the atmosphere and not to a nearby object
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff

Partial preview of the text

Download Transmission Lines and Antennas: A Comprehensive Guide with Questions and Answers and more Exams Electrical and Electronics Engineering in PDF only on Docsity!

ATT TEST 12 LATEST TEST 2025 (COMPLETE TEST) |

ALL QUESTIONS AND CORRECT ANSWERS |

GRADED A+ | VERIFIED ANSWERS | NEWEST

VERSION

What develops the characteristic impedance of the transmission line cable? ---------CORRECT ANSWER-----------------Combination of the resistance, capacitance, and inductance of the cable What needs to happen to transfer the maximum amount of energy from the source to the load? ---------CORRECT ANSWER-----------------Impedance must be matched or equal between input and output What is the result of mismatched impedance? ---------CORRECT ANSWER-----------------Damaging standing waves reflected back toward the source, causes loss of power What is skin effect? ---------CORRECT ANSWER-----------------High frequency current that has a tendency to flow to the outside of the conductor What is induction loss? ---------CORRECT ANSWER-----------------When mag field expands and contracts inducing voltage and current into conducting material near the transmission lines What is radiation loss? ---------CORRECT ANSWER-----------------Loss to the atmosphere and not to a nearby object

What type of loss is normally in the form of heat dissipation? --------- CORRECT ANSWER-----------------Dielectric loss How is dielectric loss held to a minimum? ---------CORRECT ANSWER------ -----------High resistance dielectric (insulation) What type of wire has a solid center conductor and a braided outer conductor separated by a dielectric material? ---------CORRECT ANSWER- ----------------Coaxial cable What type of transmission line has very little radiation loss? --------- CORRECT ANSWER-----------------Coaxial cable What cable is used mainly for TV reception and transmission of low power frequencies up to 200MHz? ---------CORRECT ANSWER-----------------Twin Lead line What transmission line is the simplest and least expensive and used for low volts/low frequency? ---------CORRECT ANSWER-----------------Twisted pair What is a waveguide? ---------CORRECT ANSWER-----------------A system of material boundaries capable of guiding electromagnetic energy

What is the iris? ---------CORRECT ANSWER-----------------Metal diaphragm located in waveguide, contains opening called window or aperture (used to provide impedance matching) What is the bending, twisting, joining, and installation of waveguides called? ---------CORRECT ANSWER-----------------Waveguide plumbing What are two classifications of transmitting antennas? ---------CORRECT ANSWER-----------------Hertz and Marconi What is a measure of the antennas ability to focus energy in one or more specific directions? ---------CORRECT ANSWER-----------------Directivity What type of antenna has low directivity? ---------CORRECT ANSWER------- ----------Omnidirectional What is the ability of an antenna to act as a transmitting or receiving antenna? ---------CORRECT ANSWER-----------------Reciprocity The direction of polarization is the direction of _____ ---------CORRECT ANSWER-----------------The electric vector

Radar and microwave antennas are usually _____ ---------CORRECT ANSWER-----------------Directional What are two characteristics of directional antennas? ---------CORRECT ANSWER-----------------Directivity and power gain What antenna is used most often for microwaves? ---------CORRECT ANSWER-----------------Feed horn What antenna is used for height finding and where a highly directive pattern in vertical and broader pattern in horizontal is needed? ---------CORRECT ANSWER-----------------Orange-peel What does RADAR stand for? ---------CORRECT ANSWER----------------- Radio Detection and Ranging What are the purpose of RADAR systems? ---------CORRECT ANSWER---- -------------Measures VELOCITY and LOCATION of an object by determining time required for electronic signal to travel to and from object What can RADAR detect? ---------CORRECT ANSWER----------------- Position, heading, bearing (azimuth), altitude, speed What is LOS? ---------CORRECT ANSWER-----------------Line of Sight, line form radar set directly to object

What part of radar system produces electromagnetic energy in the form of continuous waves or short powerful pulses? ---------CORRECT ANSWER--- --------------Transmitter What part of radar system is an RF switch that permits radar system to use a SINGLE antenna to both receive/transmit? ---------CORRECT ANSWER-- ---------------Duplexer What part of radar system focuses transmitted EM energy into a beam, radiates it out into space, and catches the echo signal? ---------CORRECT ANSWER-----------------Antenna Which part of radar system consists of electromechanical devices such as synchros, servos, and gyros that correctly position antenna? --------- CORRECT ANSWER-----------------Antenna control Which part of radar system amplifies and concerts returned RF echo into video signal? ---------CORRECT ANSWER-----------------Receiver Which part of radar system analyzes video signal from receiver, detects inconsistent returns, and shapes signal for clarity? ---------CORRECT ANSWER-----------------Video processor Which part of radar system uses processed video signals to give operator visual indication of object info? ---------CORRECT ANSWER----------------- Display

How is gain of an active device (amp) or loss of a passive device (attenuator) expressed? ---------CORRECT ANSWER-----------------Decibels (dB) Decibels represent a change in what? ---------CORRECT ANSWER----------- ------Power level What is the ability of a radar to distinguish multiple targets from one another when they are close together? ---------CORRECT ANSWER---------- -------Resolution What are two types of radar resolution? ---------CORRECT ANSWER--------- --------Range and Bearing (angular) resolution What plays a large part in quality of range resolution? ---------CORRECT ANSWER-----------------Pulse Width What is the ability of radar to separate objects at the SAME range but at DIFFERENT bearing or elevation angles? ---------CORRECT ANSWER------ -----------Bearing (angular) resolution What is the ability of the radar to determine range, bearing, and height of an object? ---------CORRECT ANSWER-----------------Radar accuracy

A stationary objects phase is always the _____ ---------CORRECT ANSWER-----------------Same What type of radar transmits a constant flow of EM energy NOT REFERENCED TO TIME? ---------CORRECT ANSWER----------------- Continuous wave Which radar uses multiple antennas to transmit and receive RF energy? ---- -----CORRECT ANSWER-----------------Continuous wave CW radars cannot determine _____ but are used to determine _____? ------ ---CORRECT ANSWER-----------------Range, an objects velocity Which system is similar to continuous wave radar? ---------CORRECT ANSWER-----------------Frequency modulation How do frequency modulation systems work? ---------CORRECT ANSWER- ----------------Compare frequency of received signal to a fixed reference signal What can frequency modulation systems provide that CW can't? --------- CORRECT ANSWER-----------------Range and bearing info

What type of radar provides a way to measure round-trip transmit time of transmitted signal by constantly changing frequency to provide range? ------ ---CORRECT ANSWER-----------------Frequency modulated CW (FM-CW) What type of radar provide range and bearing info to surface contacts, coastal nav points, and slow low-flying aircraft? ---------CORRECT ANSWER-----------------Surface search radar What type of air search radar does the FAA use for commercial air traffic control? ---------CORRECT ANSWER-----------------Long and short range air search radar What does the military use air search radar for? ---------CORRECT ANSWER-----------------Air traffic control and airborne target detection What type of radar is used to land aircraft during periods of low visibility? --- ------CORRECT ANSWER-----------------Specialized 3D radar called precision approach radar (PAR) What type of radars locate targets and direct weapon systems to targets? -- -------CORRECT ANSWER-----------------Tracking radar What do tracking radars provide? ---------CORRECT ANSWER----------------- Range, bearing, and elevation data of one or more targets (very accurate)

What antenna is used to find objects bearing because of a narrow horizontal beam? ---------CORRECT ANSWER-----------------Truncated parabola What are three branches of electronic warfare? ---------CORRECT ANSWER-----------------electronic support measures, electronic counter measures, and electronic counter counter measures Which part of electronic warfare search RF spectrum for emissions and analyze results to exploit weapons or sensors involved? ---------CORRECT ANSWER-----------------Electronic support measures What is the ability of an RF spectrum system to reject unwanted radiations and minimize its own transmissions from causing interferance? --------- CORRECT ANSWER-----------------Electromagnetic compatibility (allows radars to operate at optimum performance level What is referred to as active ECM? ---------CORRECT ANSWER--------------- --Jamming What is a form of passive ECM? - --------CORRECT ANSWER----------------- Chaff (creates clutter or false targets)

What are two categories of electronic counter-countermeasures? --------- CORRECT ANSWER-----------------Denial and deception (active and passive) What type of devices are used to produce signals designed to prevent detection and tracking of targets? ---------CORRECT ANSWER----------------- Active denial ECM What are 5 types of active denial ECM? ---------CORRECT ANSWER-------- ---------CW jamming, spot noise, sweep jamming, sidelobe repeater, barrage noise What is generation of RF noise in particular band or frequency channel to change signal to noise ratio of radar receiver ---------CORRECT ANSWER-- ---------------Spot Noise What type of ECM is uses non-electronic devices to prevent detection and tracking? ---------CORRECT ANSWER-----------------Passive denial What are three types of passive denial ECM? ---------CORRECT ANSWER- ----------------Chaff, reduced radar cross section (RCS), and radar absorbing materials (RAM) What type of ECM uses electronic devices to produce false echo signals to deceive and confuse a radar receiver? ---------CORRECT ANSWER---------- -------Active deception

What are two types of LEDs used for fiber optics? ---------CORRECT ANSWER-----------------Heterojunction and homojunction What does LASER stand for? ---------CORRECT ANSWER----------------- light amplification by stimulated emission of radiation What is responsivity? ---------CORRECT ANSWER-----------------Compares change in the detectors current with the change in incident light power What determines detectors optimum wavelengths? ---------CORRECT ANSWER-----------------Composition