30. Bandwidth 2. wave propagation, including ground wave and ionospheric propagation, goes on to make this text a useful and self-contained reference on antennas and radio wave propagation. 50. Explain in detail ionospheric propagation. In uniform linear array as the array length is increased to increase the directivity, the secondary lobes also occurs. The lowest useful HF for a given distance and transmitter power is defined as the lowest frequency that will give satisfactory reception for that distance and power. 52.How radiations are created from a short Dipole? Derive the expression for radiation field and radiation resistance. Wave that is guided along the earth’ s surface like an EM wave is guided by a transmission is called surface wave. CONDITIONS: Given this lesson material, pencil, paper and without supervision. (ie 10 Km from Earth surface). 6.Explain in detail the different cases of the array containing two isotropic sources. ANTENNAS AND WAVE PROPAGATION 2015 U N I T W I S E B I T B A N K –K . What are the type of fading.? i. [ ] a) Linear. Wave front is basically a locus of points acquiring similar. The applications of helical antenna are: . Ground wave classified into two types. It states that the vector product of electric field intensity vector E and the magnetic filed intensity vector H at any point is a measure of the rate of energy flow per unit area at that point.The direction of power flow is perpendicular to both the electric field and magnetic field components. The ratio of the major to the minor axes of the polarization ellipse is called the Axial Ratio. While a rigorous analysis of an antenna is highly mathematical, often a simplified analysis is sufficient for understanding the basic principles of operation of an antenna. The radiation field will be produced at a larger distance from the the current element ,where the distance from the centre of the dipole to the particular point is very large.It is also called as distant field or far field. A short dipole is initially in neutral condition and the moment a current starts to flow in one direction,one half of the dipole require an excess of charge and the other a deficit because a current is a flow of electrical charge.Then ,there will be a voltage between the two halves of the dipole.When the current changes its direction this charge unbalance will cause oscillations.Hence an oscillating current will result in an oscillating voltage.Since,in such dipole,electric charge oscillates ,it may be called as Oscilllating electric dipole. The power radiated from an antenna per unit solid angle is called the radiation intensity U (watts per steradian or per square degree). 73.What are the parameters to be considered for the design of an helical antenna? EmoticonEmoticon. 36. MCQ in Radiation and Wave Propagation Part 1 as part of the Communications Engineering (EST) Board Exam. Derive the expression for power radiated by a current element and its radiation resistance. Multi path fading is caused by interference between the direct and ground reflected waves as well as interference between two are more paths in the atmosphere. 19. 41. Find the radiated power of an antenna if 10 Amp current exists and its radiation resistance 32 ohm. For any layer , the highest frequency that will be reflected back for vertical incidence is fcr = 9¥1max. The effective height h of an antenna is the parameter related to the aperture.It may be defined as the ratio of the induced voltage to the incident field.i.e H= V / E. The fields around an antenna may be divided into two principal regions. MCQ Multiple Choice Questions and Answers on Antenna and Wave Propagation. Derive the expression for Permitivity and conductivity of ionized gas. Antenna Wave Propagation Questions With Answers related files: 87244389a5b844c4a277fb9944d1a6da Powered by TCPDF (www.tcpdf.org) 1 / 1 The frequency of the radio wave determines many of the characteristics of the transmission. In which kind of waveform is the phase velocity defined? Directivity from beam area(WA ). Ans:The dipole has two equal charges of opposite sign oscillating up and down in a harmonic motion.The charges will move towards each other and electric filed lines were created.When the charges meet at the midpoint, the field lines cut each other and new field are created.This process is spontaneous and so more fields are created around the antenna.This is how radiations are obtained from a short dipole. Derive the expression for radiation resistance of loop antenna with circumference equal to wavelength. 17.Explain diversity reception.? Visit Wisdom jobs to look into the various Antenna jobs available along with the training and assessment material for improving your knowledge base and sample resumes for a winning job and Antenna interview questions. a. This Data Communication and Networking – Analog Transmission multiple choice Based Questions and Answers PDF cover the below lists of topic. Multi path fading. Thus WA = WM+ Wm . Subscribe via Email, to get the latest articles [updates] from this site. 1 cm – 10 cm c. 10 cm – 1 m d. 0.1 cm – 1 cm ANSWER: 1 cm – 10 cm 2) Which among the following is an application of high frequency? RADAR SYSTEMS Questions and Answers pdf :-UNIT I :-1. … W’ = I2 R Rr = W’/ I2 Where Rr is a fictitious resistance called called as radiation resistance. The need for a binomial array is i). Waves propagated over other paths near the earth surface is called ground wave propagation. It is obtained by two ways. (See Figure from John. Page 5 MULTIPLE CHOICE QUESTIONS UNIT-3: ANTENNA ARRAYS 1. Visit our Antenna job interview questions and answers page designed by our experts … How wideband operation is possible with this antenna. 23. Scattering aperture(As.) The total field pattern of an array of non isotropic but similar sources is the product of the i) individual source pattern and ii) The array pattern of isotropic point sources each located at the phase center of the individual source having the same amplitude and phase. What is meant by identical Point sources.? What is inverse and multi path fading.? Electrically Small loop antennas have small radiation resistances that are usually smaller than their loop resistances.They are very poor radiators and seldom employed for transmission in radio communication. The total beam area ( WA) consists of the main beam area ( WM ) plus the minor lobe area ( Wm) . Antennas and Wave Propagation is written for the first course on the same. 24. This preview shows page 1 - 4 out of 31 pages. 6.What are the different types of aperture.? Derive the maxima ,null directions and also the beamwidth of a Endfire array. 21.Explain the concept of Reflection and refraction wavesby the ionosphere. Explain about the frequencies used for radar 5. 53.Why a short dipole is also called an elemental dipole? Antenna and wave Propagation, AWP Questions For placement and exam preparations, MCQs, Mock tests, Engineering Class handwritten notes, exam notes, previous year questions, PDF free download LectureNotes.in works best with JavaScript, Update your browser or enable Javascript Relation between and Skip Distance, Multi-hop Propagation. ... 21. rectangular,square,triangular and hexagonal), 67.Give an expression of radiation resistance of a small loop Radiation resistance of a small loop is given by Rr=31,200 (A/_ 2)2, 68.How to increase the radiation resistance of a loop antenna. Explain in detail about the aperture Concept, 3.Briefly explain the radiation from a short dipole. 2 III Year – I SEMESTER T P C 3+1 0 3 ANTENNAS AND WAVE PROPAGATION OBJECTIVES UNIT I ANTENNA FUNDAMENTALS: Introduction, Radiation Mechanism –single wire, 2 wire, dipoles, Current Distribution on a thin wire antenna.Antenna Parameters - Radiation Patterns, Radio waves are easy to generate and are widely used for both indoor and outdoor communications because of their ability to pass through buildings and travel long distances. Derive the radiation field and radiation resistance from a half wave dipole. 88 .Define frequency diversity Reception. 100. (E Volts/m). The book begins with an introduction that discusses the fundamental concepts, notations, representation and principles that govern the field of antennas. (Ae). This means that if a sinusoidal voltage is input at the antenna terminals with amplitude 1 Volt, the current will have an amplitude of 1/50 = 0.02 Amps. get the antenna wave propagation questions with answers partner that we provide here and check out the link. ._Many satellites including weather satellites,data relay satellites all have helical antennas . • V elocity of propagation of a wave in free space is giv en by 3 × 10 8 m/s. End fire array c. Collinear array. ii. It is also called as isotropic source or omni directional radiator or simply unipole. 16. It is used in normally in microwave links, and it is found that signal transmitted over the same path in two polarizations have independent fading patterns.in broad band dish antenna system, Polarization diversity combined with frequency diversity reception achieve excellent results. What is meant by similar Point sources.? 29.i)What is folded dipole antenna ? Effective aperture(Ae). Axial mode of operation. To minimize the fading and to avoid the multi path interference the technique used are diversity reception. 76.List the applications of helical antenna. ii) With neat sketch explain the operation of Helical antenna. Multiple Choice Questions ∇ × ∇ × E is ∇ ∇ .E −∇2 E ∇2 E − ∇ ∇ .E ∇2 .E + … - Selection from Antennas and Wave Propagation [Book] A pinoybix mcq, quiz and reviewers. _It is used as probes for field measurements and as directional antennas for radio wave navigation . It depends on i. Lecture 4 - Practical Machine Learning 1.pptx, Malaviya National Institute of Technology, Jaipur, ECE-VI-ANTENNAS AND PROPAGATION [10EC64]-NOTES, MCQ in Electronics - Wave Propagation And Antenna, Malaviya National Institute of Technology, Jaipur • CSE 306, Visvesvaraya Technological University • ELECTRICAL NA, Sri Sivani College of Engineering • CSE 509, University of Pangasinan • ECE 111005619. Electronics and Communication Engineering ECE FAQ Antennas and Wave Propagation Unit wise Two Marks, Short, Viva, Interviews Questions and Answers PDF 38. wave velocity vp = c / ¥__- (fc / f)2 Group velocity, vp vg = c2 vg = c2 / vp. Antenna Wave & Propagation - Important Questions with Answers TQ, visit us again. Loss aperture. Scattering aperture. Inverse bending may transform line of sight path into an obstructed one. 1 cm – 10 cm c. 10 cm – 1 m d. 0.1 cm – R A V E E N D R A M . Antenna beam width is an angular width in degrees, measured on the radiation pattern (major lobe) between points where the radiated power has fallen to half its maximum value .This is called as “beam width” between half power points or half power beam width.(HPBW). 2. Derive the expression for the radiated field from a short dipole. MUF = fcr_VHF_ i. 33.i) Write a short note on Traveling wave antenna. ._, Useful tool in designing antenna ._It approximates the pattern of a complicated array without making lengthy computations. 75.Which antenna will produce circularly polarized waves Helical antenna radiates circularly polarized wave. (Ap). 31.i) Explain the construction of Yagi antenna. 55.Why a short dipole is called a oscillating dipole? Explain the geometry of a log periodic antenna. UGC NET PAPER-I (ENGLISH) EXCLUSIVE ONLINE COURSE @ JUST RS 399 /- ONLY, Antennas and Wave Propagation Viva Short Questions and Answers PDF, : Credits goes to the faculty and staff of Pavendar Bharathidasan Institute of Information Technology -, DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING. MCQ quiz on Antenna and Wave Propagation multiple choice questions and answers on antenna and wave propagation MCQ questions quiz on antenna and wave propagation objectives questions with answer test pdf. i. Antenna asics Multiple hoice Test Student’s name: Total points: 1. 59.At what distance from the dipole is the induction field equal to the radiation field? 42. Since radio transmission is Omni directionalin nature, the need to physically align the transmitter and receiver does not arise. Course Hero is not sponsored or endorsed by any college or university. Antenna is a transition device or a transducer between a guided wave and a free space waveor vice versa. In this array the elements are fed parasitically to reduce the problem of feed line. Normally the electric field E is perpendicular to the direction of wave propagation. When the length of the short dipole is vanishingly small,then such a dipole is called a infinitesimal dipole.If dl be the infinitesimally small length and I be the current,then Idl is called as the current element. The required field strength which in turn depends upon the radio noise at the receiving location and type of service involved . Derive the expression for refractive index of ionosphere and critical frequency. Dr.V.Thrimurthulu Lecture Notes Antenna & Wave Propagation CREC Dept. PDF | On Apr 2, 2013, mahendra Kumar published multiple choice questions on wireless communication | Find, read and cite all the research you need on ResearchGate Normal mode of operation 2. i. It is an array in which the amplitudes of the antenna elements in the array are arranged according to the coefficients of the binomial series. It is the addition of above three apertures. The power is given to one element from that other elements get by electro magnetic coupling. The presence of near by antenna no.2 induces a current in the antenna no.1 indicates that presence of antenna no.2 changes the impedance of the antenna no.1.This effect is called mutual coupling and results in mutual impedance. Tower . iii. Antenna And Wave Propagation Questions With Answers File Type PDF Antenna And Wave Propagation Questions … Antenna asics Multiple hoice Test - ETH Z Antenna asics Multiple hoice Test Student’s name: Total points: 1 The propagation speed of an EM wave depends on the Medium Frequency Polarization Power 2 Which of Broad side array. i) Effective aperture. A. Antenna array . 28. _It is on many othe probes of planets and comets,including moon and mars,being used alone,in arrays or as feeds for parabolic reflectors,its circular polarization and high gain and simplicity making it effective for space application. Define dipole antenna. iii. 9.Explain the principle of pattern multiplication with some examples. If an e.m.f is applied to the terminals of an antenna no.1 and the current measured at the terminals of the another antenna no.2, then an equal current both in amplitude and phase will be obtained at the terminal of the antenna no.1 if the same emf is applied to the terminals of antenna no.2. Also includes the portion of energy received as a result of diffraction around the earth surface and the reflection from the upper atmosphere. 1) What is the wavelength of Super high frequency (SHF) especially used in Radar & satellite communication? Collecting aperture. Electronics and Communication Engineering ECE FAQ Antennas and Wave Propagation Unit wise Two Marks, Short, Viva, Interviews Questions and Answers PDF. Write the relative factors between the radar’s cross section of the target and its true cross sections 3. The maximum amplitudes of the individual sources may be unequal. D = P(q,f)max / P(q,f)av. 4. D = 4p / WA. Attenuation of this wave is directly affected by the constant of earth along which it travels. The field amplitude due to half wave dipole at 10km is 0.1 V/m. It is made up of direct wave and ground reflected wave. What is meant by front to back ratio.? 12.Derive the expressions for the fields and power radiated from a half wave dipole antenna.Find its radiation resistance and directivity. Space diversity reception. The ratio of the effective aperture to the physical aperture is the aperture efficiency. This is the Multiples Choice Questions Part 1 of the Series in Antennas as one of the Communications Engineering topic. However, their powe… Give it a try and share your score. Called as elementary dipole, elementary doublet and hertzian dipole need for a rhombic antenna antennas and wave Part! Plane of polarization will usually have changed, this phenomenon is known as Faraday ’ name. 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