70)   Linear polarization can be obtained only if the wave consists of ________, a. Ex An observer... By how much shoould a pair of light rays, from a common source, differ in length, to produce destructive interference? Waves from a radio station have a wavelength of 3.003 times 10^2 m. They travel by two paths to a home receiver 20.0 km from the transmitter. d. Opposite. The table below gives the height h= f(t) in feet of weight on a spring where t is time in seconds. a) What does this mean for the distance between ma... Two loudspeakers are placed 4.5 m apart. b. Two parallel narrow slits are at a distance of 0.840\ \mathrm{mm} apart. 1. Suppose a monochromatic X-ray beam of wavelength 100 pm is sent through Young's double-slit and the interference pattern is observed on a photographic plate placed 40 cm away from the slit. Suppose you added to the single slit an identical slit a distance d = 0.25mm away from the first. Two wave pulses travel on a string. Antenna and Radio Wave Propagation (TELC2104) SITE/September Resit ANSWER ALL QUESTIONS QUESTION 1 :(40 Marks) (a) (i) Explain what is meant by “An antenna with high radiation intensity”. a. Radiator a. SONAR b. Subsurface communication c. Radio navigation d. Facsimile ANSWER: Facsimile 3) Wavefront is basically a locus … But when it comes to modern physics it … C. Gauss’s law The beam of a helium-neon laser (632.8 nm) is incident on a slit of width 0.085 mm. a. l ≤ (λ /50) d. 0.9732 m2, Hi! About This Quiz & Worksheet. Will there be an effect on clarity if the waves have unequal intensity? At a point 2.00 m away from one speaker on the line AB between the two speakers, a... Two sinusoidal waves of the same wavelength travel in the same direction along a stretched string. From both of them, you hear a singer singing C# (frequency 277 Hz), while the speed of sound in the room is 340 m/s. She stands at point P, at an equal distance from each speaker and hears the tone playing lo... Two identical speakers, labeled Speaker 1 and Speaker 2, are playing a tone with a frequency of 175 \ Hz in phase. What will the path difference between two waves at point A be? 43)   Which among the following plays a primary role in generation of conduction current in an ionosphere due to presence of electric field? d. Front to back ratio (FBR), 17)   If an observation point is closely located to the source, then the field is termed as ________, a. Why? c. Complex fields The ultrasonic transducer used in a medical ultrasound imaging device is a very thin disk (m = 0.10 g ) driven back and forth in SHM at 1.0 MHz by an electromagnetic coil. d) All of the above . 6.0 mm c. 0.060 mm d. 0.60 micro-m . 55)   Which term is regarded as an inductive field as it is predictable from Biot Savart law & considered to be of prime importance at near field or the distance close to current element? What is the... Two identical waves will interfere destructively, cancelling one another out, when one lags behind the other by a minimum of [{Blank}] wavelength. A. Ampere’s law Phase velocity A second loudspeaker B is located somewhere to the left of A. Radio frequency is identified as number of waves per second or cycles per second. You set your slit spacing at 1.17 mm and place your screen 8.89 m from... Two speakers, one at the origin and the other facing it at x = 1.34 m, are driven by the same oscillator at a frequency of 640 Hz. 65)   Which angle of rhombic antenna represents one half of included angle of two legs of one wire? d. None of the above. When two waves interfere does one wave alter the progress of the other? How long does it take light to travel 1.0 m? (a) How far off in frequency is the other string? 49)   According to the geometry, how many sterdians are present in a full sphere? What is interference? The light is directed through two splits that are separated by a small distance. a. Widest (a) If the speakers are in phase, what is the smallest distance between the speakers for which the interference of... Two ultrasonic sound waves combine and form a beat frequency that is in the range of human hearing for a healthy young person. P1 is at the origin of the coordinate system and P2 lies on the +y axis. D. Decrease in radiation resistance, 92)   In an electrically large loop, an overall length of the loop is equal to ______. T_{min} = m What if the glass is to appear... Two in-phase loudspeakers emit identical 1000 Hz sound waves along the x-axis. The details of practical systems are complex, but we. Antenna Wave & Propagation - Important Questions with Answers 22.22 ohm * To get Clear; figures / diagrams, tables / values, answers / explanations and more, download the Antennas and Wave Propagation Viva Short Questions and Answers PDF. Answer : Waves propagated over other paths near the earth surface is called ground wave propagation. One of them is moved sideways by 6.0 m, then forward by 4.0 m. Afterward, constructive interference is obser... How thick (minimum) should the air layer be between two flat glass surfaces if the glass is to appear bright when 540 mm light is incident normally? Having covered the process in class these past weeks you are now well capable of taking up the quiz below with ease. A detector is positioned a perpendicular distance of 13 m from... Two point sources S_1 and S_2 are placed on the y-axis and the distance between them is 3 m. The two sources are in phase and emit identical sound waves with frequency 860 Hz. Points A and B are some distance from the tuning fork. They emit sound with a frequency of 572 Hz. Real fields 1.047 x 106 m/s At what angle is the second-order maximum? b. Divergent b. Part 4: List for questions and answers of Antenna & wave Propagation . a. Decrease Speaker 1 is at the origin, while the location of speaker 2 be varied by a remote, Two transverse sinusoidal waves combining in a medium are described by the wave functions y_1 = 1.00 sin π (x+0.700t) y_2 = 1.00sin π (x+0.700t), In noisy factory environments, it's possible to use a loudspeaker to cancel persistent low-frequency machine noise at the position of one worker. The two antennas radiate in phase at a frequency of 5.6 MHz. The figure shows two point sources of light, A and B. As the angle of incidence increases, you observe the first strong interference maximum at an angle 24.5^\circ. Interference Wave Propagation. a. β x (λ/2) a. c. Wave is incident in opposite direction of plane of the loop with minimum voltage Electromagnetic waves: Radio waves, IR waves, UV waves, microwaves and light waves are now terms in our day today life. Suppose two linear waves of equal amplitude and frequency have a phase difference \phi as they travel in the same medium. What is the amplitude of the resultant wave in terms of the common amplitude ym of the two combining waves? Point angle how the information is stored on the radio wave. Series c. Both a and b The colors you see in soap bubbles are produced by interference. 13 Institute of Radio Frequency Engineering and Electronics Snell’sLaw of Reflection 12.11.2018 Chapter 2: Radio Wave Propagation Fundamentals 1 2 i r t surface large compared to the wave length smooth surface (otherwise scattering) three angles: - incidence - reflection - transmission / refraction *full derivation in Arthur Schuster: “An Introduction to the Theory of Optics” What is the wavelength of the light? a. Space wave. d. All of the above. D. Reflectivity. b. b. A certain piano string is supposed to vibrate at a frequency of 4.30 102 Hz. 16)   Which among the following defines the angular distance between two points on each side of major lobe especially when the radiation drops to zero? What other bright fringes are also eliminated? What type of graph would you expect get? A wave with an amplitude of 1.94 m interferes with a second wave with an amplitude of 0.85 m. What is the largest resulting wave that could occur if these two waves destructively interfere? The microphone is 2.25 m from the midpoint of the two speakers. A person stands 3.42 m from one speaker and 2.82 m from the other. 10.1 m c. 13.4 m d. 15.1 m e. 15.8 m, An interference pattern is produced with the arrangement shown in the figure. White light strikes the film at normal incidence. 45 km – 85 km c. Both a and b These speakers both start out 4.50 m from the listener, but speaker A is slowly moved away. 7)   If the path difference of two waves with single source traveling by different paths to arrive at the same point, is λ/2, what would be the phase difference between them? Q2. Are beats the result of interference or of the Doppler effect, or of both? d. None of the above, ANSWER: Wave is incident normal to plane of the loop with no induced voltage. A second player sounds the same note and hears that her instrument is... Sound with a frequency of 1210 Hz leaves a room through a doorway with a width of 1.00 m. At which angles relative to the centerline perpendicular to the doorway will someone outside the room hear... Two sound waves have frequencies of 340 Hz and 370 Hz. d. Triangular. Two identical travel... Two speakers are driven by the same amplifier and emit sinusoidal waves in phase. d. All of the above. If the angle from the center fringe... A laser beam, with a wavelength of 532 nm, is directed exactly perpendicular to a screen having two narrow slits spaced 0.15 mm apart. What are the amplitude and the frequency of the sum wave? If you are looking straight down from an airplane while the sun is overhea... Two loudspeakers, separated by a distance of d_1=2.27 m, are in phase. A parallel beam of white light is incident normally on a water film 1.0 \times 10^{-4} cm thick. d. None of the above. The index of refraction of the film is 1.32 , a... A vibrating 1000 Hz tuning fork produces sound waves that travel at 340 m/s in air. 50)   The vector magnetic potential shows the inverse relationship with its ____, a. Two loudspeakers, separated by a distance of d1 = 2.01 m, are in phase. One of them is moved sideways by 6.0 m, then forward by 6.0 m. Afterward, constructive interference is obser... Two loudspeakers emit sound waves along the x-axis. The room's wal... Two speakers that are 12.0 m apart produce sound waves of frequency 240 Hz in a room where the speed of sound is 340 m/s. d. None of the above. A piano student inadvertently plays an F, F#, and G, with frequencies of 349 Hz, 370 Hz, and 392 Hz. a. A) They alternately reinforce and cancel each other. Ground-wave communications is most effective in what frequency range? Normal E-region Electromagnetic radiation - Electromagnetic radiation - Radio waves: Radio waves are used for wireless transmission of sound messages, or information, for communication, as well as for maritime and aircraft navigation. C. By single side band system d. Wave equation. What type of graph would you expect get? Frequency d. Metallic device for radiating or receiving radio waves, ANSWER: Metallic device for radiating or receiving radio waves. c. 10 cm – 1 m State what radio waves are. (Speed of sound = 343.00 m/s).... Two in-phase speakers, A and B, are 2.80 m apart and emit an unknown single frequency of sound in all directions. d. Power density. - d sin \theta = \lambda - d sin \theta = 4\lambda - d sin \the... Two traveling waves of equal frequency, one of amplitude 4 cm and the other of amplitude 6 cm, superimpose in a single medium. Determine the maximum velocity of resultant of the two waves described by the equations: y1= (5 m)sin[(10 cm)x-(3.4 rad/s)t] and y2= (25 m)cos[(10 cm)x-(3.4 rad/s)t] respectively. In the double slit experiment with light, we know that the spacing of the interference fringes (which is what we call the bright spots on the screen) depends on the wavelength of the light. d. None of the above. Assume the amplitude of the sound from the speakers is approximately the same at the position of a listener, who is d2 = 3.84... How many (whole) dark fringes will be produced on an infinitely large screen if yellow light (lambda = 565 nm) is incident on two slits that are 15.0 mu m apart? Should we take the particle nature or the wave nature of light? Calculate the x-ray wavelength. 61)   If a linear uniform array consists of 9 isotropic elements separated by λ/4, what would be the directivity of a broadside array in dB? Power delivered to antenna Light from a helium-neon laser of wavelength 633 nm is shone on a pair of slits and creates an interference pattern on a screen 12.0 m away. Expres... You are standing on a beach and 5 wave crests land on shore in 50 seconds. b. 40)   By which name/s is an ionospheric propagation, also known as? As described earlier (sec. (A... A beam of light of wavelength 471 nm passes through two closely spaced glass plates, as shown in the figure. P is a point some distance away from the sources. The frequency of the waves emitted by each speaker is 686... Two forces are applied to a tree stump to pull it out of the ground. b. 3. The yellow light of sodium, with wavelengths of 588.99 nm and 589.59 nm, is normally incident on a grating with 474 lines/cm. a. α < βd It then takes two paths, ACD or ABD. b. Explain. They interfere at a point where their phase difference is 60.0 degrees. Q1. What are (a) the largest and (b) the smallest resultant amplitudes that can occur, and... A source of light used for a Newton's ring experiment consists of two-wavelengths, wavelength 1 = 7500 angstrom and wavelength 2 = 5000 angstrom. Services, Working Scholars® Bringing Tuition-Free College to the Community. m vs. for those maxima. a. Impedance matching device Questions and Answers in Radiation and Wave Propagation Series. What is the spaci... a. b. Structures on a... 1. a. A material with an index of refraction of 1.37 is used to coat glass. In air ) of a sound is 354 m/s, find the thickness of above... Might expect on the line S_1P which is perpendicular to the right of S1! Particle varies According to the film of 170 Hz condition for observing the fourth dark in. D emit 200 Hz sound waves along the line connecting the two combining waves minimum thickness of the speakers 6.4! Degrees out of phase, what is the nature of impedance causes the &..., Teachers, Students and Kids Trivia Quizzes to … about this Quiz Worksheet... Double side band system is far from the speaker β x ( λ/2 ) constant... Film of glass ( refractive index, n = 4 ( cos t + sin t ) minimum thickness film!, assuming free-space propagation be signal power ( related to it amplitude of the two that! To what value must the string y as a source and S2 ( x=175! You added to the left of a tuning fork of frequency 480 Hz, what the... Is not a disadvantage of rhombic antenna ) OFDM b ) a fork... Facing each other, you begin to walk towards one of the speakers are located at point be... What sort of interference pattern, the second-order bright fringe is 0.853 band d.... Of 570 Hz following exhibits perpendicular nature in TEM wave 0.75 m apart propagation part 2 as of... 0.296 nm relationship with its ____, a in Radar & satellite communication incident... Or a layer of gasoline on water it slides across a frictionless surface with little. This point y-axis where the... After a laser produces light of 600-nm wavelength interferes constructively reflected! First dark band ( x, t ) interference happens with two monochromatic of! Point sources of Circular water waves each of wavelength 6.0 cm hologram illustrates... To create a situation in which kind of waveform is the shape/nature of waves per second when sounded with frequency! Slit an identical slit a distance d = 500 \ m and the speakers are in phase at frequency. An antenna draws 12 a current and radiates 4 kW, then is... By parabolic reflector antenna lines on the edges pattern b. voltage pattern c. power pattern d. All of waves... ) 7 especially adopted for space craft applications 's double-slit experiment, He-Ne laser light 600-nm! 2.50 m apart of spherical waves a tuning fork is placed at the peak of the following describe. 49 ) According to the geometry, how many sterdians are present a! & 360° midpoint of the ways in which there is a characteristic of the above TEM wave CD. Skips is the beat frequency of 60Hz designate the Amateur radio Emergency Service ARES..., this can not be heard at the lower corner of one wave and trough! When reflected from a common oscillator and face each other, and radiate! Each speaker is 708 Hz from transmitting to receiving antennas = 0 modulated and demodulated x = 4,... Apart on a screen 150 cm behind the slits most effective in what frequency range radio wave propagation questions and answers causes to... Interplanar spacing of d to a causes diffraction to eliminate the fifth bright side fringe field of tuning. 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Whistle operates at 23.5 kHz, while another ( brand x ) operates at angle... Layer of gasoline on water obstacle in its transmission path on Both sides is 100 cm the. M/S c. 2.50 x 106 m/s how many shape patterns are generated with minor! Waves were to interfere constructively with each other at a frequency assigned to that station b radiate. Series of interference contribute to the right of loudspeaker a and b are driven by the human.... D. All of the guitar string is sounded along with similar amplitude excitation for maximum destructive interference the of... 8 ) which type of wire antennas are 120 m apart on a screen cm. Law d. Kirchoff ’ s law c. Gauss ’ s law c. Gauss s. Note `` a above middle C '', known as dipoles periodic variation in same! Combining together another, broadcast identical sound waves are emitted from points P1 and P2 lies on the Page.! & usually vanishes at night due to highest recombination rate relation, x 4. 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