c. Angle inclination (Ψp) c. 0.5521 m2 The picture shows the displacement of the string y as a function of x at t = 0. b. Elliptical 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? a. 1.257 x 106 m/s A diffraction grating with 1000 slits/cm is oriented parallel to the y axis and its center is located on the x axis at x = -5.00 m. A source of light of wavelength 650 nm is located on the x axis a... An observer is located directly between two speakers located 20 meters apart. a. Decrease Suppose a listener standing directly between two loudspeakers hears the same tone being emi... A laser beam ( \lambda = 632.0 \; nm) is incident on two slits 0.270 mm apart. Fill in the blanks. b. Rectangular The modern term for this is hertz. They are playing identical 133-Hz tones, and the speed of sound is 343 m/s. The details of practical systems are complex, but we. b. d. None of the above, ANSWER: Its input impedance during the removal of all other antennas. 11)   The knowledge of which parameter is sufficient for deriving the time varying electromagnetic field? Consider points along the line connecting the two sources. You are standing between the speakers,... Light of wavelength 730 nm falls on two slits and produces an interference pattern in which the third-order bright red fringe is 41 mm from the central fringe on a screen 2.0 m away. A detector can be moved on the line S_1P which is perpendicular to S_1S_2. c. Back lobe How far must you move toward one speaker, in order to find a... What phase difference, between two otherwise identical traveling waves, moving in the same direction along a stretched string, will result in the combined wave, having an amplitude 1.7 times that o... A possible means for making an airplane invisible to radar is to coat the plane with an antireflective polymer. 2. The source is moving in a direction parallel to the line joining the microphones. a. Each of them has a width of 0.140\ \mathrm{mm}. ElectronicsPost.com is a participant in the Amazon Services LLC Associates Program, and we get a commission on purchases made through our links. a. b. Refracted The solution appears colored in sunlight. These speakers both start out 4.50 m from the listener, but speaker A is slowly moved away. (b) cancel completely. These two waves travel along the same string: y_1 = (4.17 mm) sin(2.24 \pi x - 300 \pi t), y_2 = (5.96 mm) sin(2.24 \pi x - 300 \pi t + 0.727 \pi rad). A) The maximum restoring... Usual values of slit separation for the double-slit experiment are on the order of 0.1 mm while diffraction gratings often have 1000 lines per mm. d. Far-field. a. (Assume the speed of sound is 345 m/s, and the observer is located equidistant fr... Light of wavelength 500 nm illuminates a soap film (n = 1.33). What wavelength (in nm) is needed to have the intensity at a point 1 mm from the cen... Two identical speakers are pointed at one another, along the x-axis. In a double-slit experiment, He-Ne laser light of wavelength 633 nm. 93)   How do the elements of an active region behave? 7. c. 180° & 270° Suppose a piano tuner hears 2 beats per second when listening to the combined sound from her tuning fork and the piano note being tuned. Which of the following equations describe the condition for observing the fourth dark fringe in an interference pattern correctly? For a charge moving with uniform velocity with straight & infinite wire 22.22 ohm Your automobile has two headlights. The third bright fringe forms on the screen 48.0 cm fart... Monochromatic light falls on a slit that is 2.10 times 10^{-3} mm wide. a. On a very large distant screen, what is the total number of bright fringes (those indi... Two speakers that are 17.0 m apart produce sound waves of frequency 225 Hz in a room where the speed of sound is 340 m/s. Waves from a radio station with a wavelength of 600 m arrive at a home receiver a distance 50 km away from the transmitter by two paths. In the experiment of Lloyd's Mirror, when a light beam is shone on a mirror and reflected, it is phase shifted by 180 degrees. By high carrier reception What is the second thinnest coating of fluorite (magnesium fluoride) that would be non-reflective for this waveleng... Two radio antennas are 120 m apart on a north-south line. 81)   In radio communication link, what is the shape/nature of waves generated by transmitting antenna? The frequency is 415 Hz. The first one is now loaded with a little wax and the beat frequency is found to increase to 6 per second. What is the wavelength of light waves if their frequency is 5.0X10 14 Hz? (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. (b) a number of sinusoidal traveling waves... Monochromatic light of wavelength 543 nm falls on a slit. Subject: Antenna and Wave Propagation 4. The vibrations are sinusoidal.... Green light of a certain wavelength is incident upon two slits separated by 2.10 \times 10^{-5} m. A screen is placed 0.800 m from the slits. Initial (a) If yellow light of wavelength 588 nm strikes the double slit, what is the separation between the zeroth-order and first-orde... A pair of in-phase stereo speakers is placed side by side, 0.704 m apart. Amateur stations must record the call sign of the primary service station before operating on a frequency assigned to that station B. Answer : Propagation of sound waves in air is an example of longitudinal wave motion. b. An observer initially hears a maximum at a dis... Two waves identical in speed, frequency, amplitude, and wavelength, but differing in phase by +pi/3 radians interfere in a region in space, where x is in cm and t is in sec. Ground-wave communications is most effective in what frequency range? How? d. None of the above, 20)   In flared transmission line, the radiation phenomenon increases due to ________ in flaring, a. Area d. Lens. c. Contingent a. incoherent b. monochromatic c. 1/2 (wavelength) d. constant. d. All of the above. b. A mixture of red light (lambda_{vacuum} = 640 nm) and green light (lambda_{vacuum} = 512 nm) shines perpendicularly on a soap film (n = 1.29) that has air on both side. c. Both a and b 1 m – 10 m Away c. Across d. Beside. c. Both a and b c. High Light, of wavelength, 631 nm, passes through a diffraction grating, having 360 lines/mm. a. β x (λ/2) d. Inverter. a. 45 km – 85 km As you walk par... (a) A 1024-Hz tuning fork is placed at the source position in the figure shown. d. None of the above, ANSWER: Distance of point from the source (R). Two loudspeakers are placed above and below each other and driven by the same source at a frequency of 3.70 x 10^2 Hz. current of about 300A across the radiation resistance 2 Ω. Power factor of impedance 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. b. Shunt b. What is the lowest frequency at which destructive interference (sound cancellation) will occur... Two pianos each sound the same note simultaneously, but they are both out of tune. Determine the two lowest possible thicknesses of the soap bubble. You are recreating Young's experiment with red laser light of wavelength lambda = 700 as a source. d. Solid angle. a. Reactive b. d. All of the above. Increase in radiation resistance Two radio antennas are 120 m apart on a north-south line, and they radiate in phase at a frequency of 3.4 MHz. A piano tuner hears one beat every 2.0 s when trying to adjust two strings, one of which is sounding 440 Hz. An observer originally positioned at one of the speakers begins to walk along a l... How is an electronic organ able to imitate the sounds of various musical instruments? ... Radio wave that is far from its sources is called . b. If the angle between the first dark fringes on either side of the central maximum is 29.0 degree (dark fringe to dark fringe)... Blue light of wavelength 455 nm passes through an interference grating with a slit spacing of 0.003 mm and makes an interference pattern on the wall. b. What is the highest-order visible maximum that is formed? b. A bicyclist between the two cars, 4.50 m from each horn, is disturbed to find she is at a point of constructi... Two loudspeakers are placed above and below each other 3.00 m apart and driven by the same source at a frequency of 4.50 x 10^2 Hz. What will be its required capture area? At what angle is the first max located? A person stands 4.6 m from one speaker and 3.4 m from the other. c. Side lobe level (SLL) |AC| = 5.00 m and the angle theta = 44 degrees . 62)   If the elements of a binomial array are separated by λ/4, how many shape patterns are generated with no minor lobes? c. Complex fields As you do, the intensity of the sound... Loudspeakers A and B are vibrating in phase and are playing the same tone, which has a frequency of 131 Hz. Moderate Its impedance by taking into consideration the consequences of other antennas If the path difference between the light waves from coherent sources reaching a point p on the screen is 20.5 \ lambda, than that is constructive or destructive interference? Answer : Waves propagated over other paths near the earth surface is called ground wave propagation. 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? Suppose two linear waves of equal amplitude and frequency have a phase difference \phi as they travel in the same medium. Electronics and Communication Engineering ECE FAQ Antennas and Wave Propagation Unit wise Two Marks, Short, Viva, Interviews Questions and Answers PDF Given that the mth mark ring of wavelength 1 coinci. Two parallel slits are illuminated by the light of two wavelengths one of which is 5.8 \times 10^{-7} m. On the screen, the fourth dark line of known wavelength coincides with the fifth bright line... Two collinear harmonic oscillation x1 = 8sin(100 pi(t)) and x2 = 12 sin(96pi(t)) are superposed. You will hear the sound that comes directly to you from the lecturer along with sound tha... An observer is located directly between two speakers, located 20m apart. C. By single side band system Antenna Wave & Propagation - Important Questions with Answers Assuming that the coating prevents reflection of yellow-green light (wavelength in vacuum = 569 nm), determine the... Sound source A is located at x = 0, y = 0, and sound source B is place at x = 0, y = 2.7 m. The two sources radiate coherently in phase. a. 19)   How are the infinitesimal dipoles represented in terms of antenna length and signal wavelength? Each memb... A loudspeaker A and point C, where a listener is positioned. d. α ≠ ±βd. As the signal can tr… You stand directly in front of one of the speakers, 1.3 m from the speaker. a. Spherical Why? (. 30)   Which mode of propagation is adopted in HF antennas? b. Take the wavelength to be 680 nm, and assume the same index of refraction... 1. a. Curvature of earth By varying the waveform of the electric signal that passes through the antenna. An antenna is an electrical conductor or system of conductors. d. Square. At a point in the pattern where the phase difference between the waves from the two slits is 62^o, wh... What will be the "beat frequency" if middle C(262 Hz) and C#(277Hz) are played together? a. Wave propagation is any of the ways in which waves travel. Potassium iodide has an interplanar spacing of d = 0.296 nm. Part 4: List for questions and answers of Antenna & wave Propagation . c. Radiated 39)   After which phenomenon/phenomena do the waves arrive at the receiving antenna in ionospheric propagation? If the index of refraction of the film is 1.38, what is the minimum thickn... A thin layer of oil (with index of refraction 1.18) is floating on water. What visible wavelengths will be constructively reflected if the film is surrounded by air on both sides? a. Capacitor Explain qualitatively the phenomenon of interference of waves. For what minimum nonzero value of the plate separation d will the transmitted light be b... A radar tower sends out a signal of wavelength \lambda. Is it possible to create a situation in which there is only destructive interference? The slits are a distance 0.13 mm apart. Find the resultant wave, b.... A flat piece of glass is held stationary and horizontal above the highly polished, flat top end of a 9.50-cm-long vertical metal rod that has its lower end rigidly fixed. Radio waves, Microwaves, or Infrared waves Multiple Choice Question and Answer . Draw the resulting interference pattern you might expect on the same screen. Briefly explain the concepts of constructive and destructive interference. When the top plate is illuminated normally with a light of wavelength 640 nm, the filament lies directly below the tenth order... Two identical loudspeakers separated by distance d emit 180 Hz sound waves along the x-axis. Describe constructive and destructive interference. 58)   If the radius of loop is λ/ 20 in a free space medium,what will be the radiation resistance of 8-turn small circular loop? 3. d. All of the above, 86)   Self impedance of an antenna is basically __________, a. Assume the amplitudes of the sound from the speakers are approximately the same at the position of a listener, who is... Two speakers, one directly behind the other, are each generating a 245 Hz sounds wave. Access the answers to hundreds of Interference (wave propagation) questions that are explained in a way that's easy for you to understand. 31)   For which band/s is the space wave propagation suitable over 30 MHz? On the other side of the slits is an interference patter... A laser beam is incident on two slits with a separation of 0.210 mm, and a screen is placed 5.10 m from the slits. b. 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”. She asks you to determine this frequency more precisely. B. b. β / (λ/2) If two waves with equal amplitudes and wavelengths travel through a medium in such a way that a particular particle of the medium is at the crest of one wave and at the trough of the other wave at... Two coherent sources of radio waves, A and B, are 5.00 meters apart. 0.0475 m2 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? Phase d. All of the above. Space wave. 50.45 Ω A laser produces light of wavelength lambda and amplitude A. 90° & 180° Answer in units of... Two out-of-phase radio antennas at x= 300m on the x-axis are emitting 3.0MHz radio waves. When a guitar string is sounded along with a 411-Hz tuning fork,a beat frequency of 44.0 Hz is heard. What physical phenomenon underlies the production of beats? c. Greater than Musicians can use beats to tune their instruments. 85)   Which property/ies of antenna is/are likely to be evidenced in accordance to Reciprocity theorem? c. α = ±βd (d) electron interference. What accounts for different colors in either a soap bubble or a layer of gasoline on water? Towards b. In Young's double-slit experiment the separation y between the first-order bright fringe and the central bright fringe on a flat screen is 0.0260 m when the light has a wavelength of 480 nm. What is the resultant amplitude? d. None of the above. Imagine a soap film (air-soapy water-air) of 1l, m thickness, and refractive index of 1.5, with white light, normal to the film. a. 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