d. None of the above. Two small stereo speakers A and B that are 1.4 m apart are sending out sound of wavelength 34 cm in all directions and all in phase. 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). 12)   According to Webster’s dictionary, what is an antenna? However, their power … Your teacher gives you two speakers that are in phase and are emitting the same frequency of sound, which is between 5000 and 10,000 \ Hz. The centers of the speakers are located 6.00 \ m apart. An observer is in front of the speakers (to the right) at point O... Two antennas radiating 6.0 MHz radio waves in phase with each other. a. Are beats the result of interference or of the Doppler effect, or of both? 22)   In an electrically small loops, the overall length of the loop is ______ one-tenth of a wavelength. One is a direct-line path and the second is by reflection fr... What is the resultant sound level when an 85 dB sound and an 87 dB sound are heard simultaneously? how the information is stored on the radio wave. Answer : Ground wave classified into two types. Go ahead and submit it to our experts to be answered. A listener walks in a circ... Two identical traveling waves, moving in the same direction, are out of phase by pi/6.0 rad. c. Both a and b If the slit separation is 0.12 mm, then what is the wave length of the light? Normal E-region 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”. Field pattern estimation due to any length of antenna m vs. for those minima. a. The modern term for this is hertz. In the figure, two loudspeakers, separated by a distance of d_1 = 2.78 m, are in phase. They are playing identical 135 \ Hz tones, and the speed of sound is 343 \ m/s. (λ/50 ) < l ≤ (λ /10) Their frequency of vibration is 2.0 Hz and the wave speed is 4.0m/s. What is the lowest frequency that will produce... Two speakers, spaced a distance 1.5 m apart, emit identical coherent sound waves at a frequency of 680 Hz in all directions. The solution appears colored in sunlight. d. None of the above. about radio wavesantennasmobile phonesradio waves in the homeradio waves and health 3.3 ns b. Monochromatic light at 577 nm illuminates a diffraction grating with 325 lines/mm. Point angle b. Radiated Two loudspeakers, separated by a distance of d1 = 2.01 m, are in phase. All radio measurements are made far from the antennas. d. Voltage. The waves produce an interference pattern such that the distance from the right bisector to a p... What beat frequencies are possible with tuning forks of frequencies 258, 263, and 267 Hz? What is the wavelength of the light? b. I.e. Tilt angle c. Along z-axis 1) What is the wavelength of Super high frequency (SHF) especially used in Radar & satellite communication? Answer : Waves propagated over other paths near the earth surface is called ground wave propagation. d. None of the above. If it is desired to have a fringe spacing of 1 mm, what is the requi... You have two vibrating objects in an infinitely large pool. These speakers both start out 4.50 m from the listener, but speaker A is slowly moved away. Sound waves, like light waves, can interfere with each other, giving maximum and minimum levels of sound. What is th... A certain dog whistle operates at 23.5 kHz, while another (brand X) operates at an unknown frequency. The sources emit energy in the form of spherical waves. B) The have the same wavelength. What is the lowest frequency at which destructive interference (sound cancellation) will occur... Two speakers are wired to emit identical sounds in unison. Determine the wavelength of light used in this experiment... A flat observation screen is placed at a distance of 3.7 m from a pair of slits. If you stand 12.0 m in front of the plane of the speakers, centered between them, you hear a sound of maximum intensity. Why? A car travels due north along a straight line at position x= 1390... Two small speakers A and B are driven in step at 725 Hz by the same audio oscillator. Plane C. Decrease in Magnetic field intensity The speed of sound... What happens when two waves of different frequencies are added together? A piano student inadvertently plays an F, F#, and G, with frequencies of 349 Hz, 370 Hz, and 392 Hz. State what the electromagnetic field is and what components make up the electromagnetic field. a. If the distance between two slits is 0.0620 mm find the angle between the second and third order bright fringe for light with a wavelength of 503 nm. b. Voltage Waves also have a wavelength to them – the distance between the same positions on two waves. The sound intensity decreases as the distance between the speakers is increase... Use the worked example above to help you solve this problem. Explain how these two types of interference contribute to the periodic variation in the loudness of sound know as "beats". The resultant wave at point A is A. a wave of the same frequency and amplitude as the two incoming wave... Two speakers emit sound of identical frequency and amplitude, in phase with each other. 3. Find the minimum order of the violet fringe (\lambda = 400 nm) which overlaps with a red fringe (\lambda = 700 nm). d. None of the above. A) They alternately reinforce and cancel each other. Frequency d. All of the above. The line-of-sight propagation will not be smooth if there occurs any obstacle in its transmission path. 90)   What is/are the major applications of an infinitesimal dipole that contribute/s to its analysis? b. Converter The ratio of intensities between a point A and that of the central fringe is 0.853. 8)   Which ionization layer exists during day time & usually vanishes at night due to highest recombination rate? They are directly facing each other, are 7.4 m apart, and are each playing a 72.0 Hz tone. a. 0.0149 m2 What is the first distance (measured from S1) at which she will hear minimum loudness? Real fields Electromagnetic waves: Radio waves, IR waves, UV waves, microwaves and light waves are now terms in our day today life. Two tuning forks sounding together result in a beat frequency of 3 Hz. The Sound of Waves Chapter XII Summary and Analysis ... Radio Waves •You hear a sound wave when the compressions and rarefactions the sound wave produces reach your ears. A monochromatic x-ray beam shows a first-order diffraction maximum when the grazing angle is 7.6 degrees. Minor lobe Find the thickness of a aluminum metal in between glass. 65)   Which angle of rhombic antenna represents one half of included angle of two legs of one wire? The fringe spacing on a screen 150 cm behind the slits is 4.0 mm. There is air both inside and outside the bubble. Determine how many of those rings are produced. 2) Twin jet engines on an airplane ar... 1) A car has two horns, one emitting a frequency of 199 Hz and the other emitting a frequency of 203 Hz. What happens to sound when interference occurs? Explain qualitatively the phenomenon of interference of waves. a. 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. Each memb... A loudspeaker A and point C, where a listener is positioned. Away c. Across d. Beside. a. 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. Reduced transmission efficiency c. Both a and b By varying the waveform of the electric signal that passes through the antenna. 26)   In which kind of array configuration, the element locations must deviate or adjust to some nonplaner surface like an aircraft or missile? A. Permittivity At low frequencies, the waves can pass through obstacles easily. Multimode graded-index propagation Multiple Choice Question and Answer. The speed of sound is 343 m/s. Get help with your Interference (wave propagation) homework. Ground wave propagation The figure shows two point sources of light, A and B. b. If the path-length difference between two identical and coherent beams is two wavelengths when they arrive on a screen, will they produce a dark or a bright spot?. a. SONAR b. Subsurface communication c. Radio navigation d. Facsimile ANSWER: Facsimile 3) Wavefront is basically a locus … a. If radar waves have a wavelength of 2.90 cm and the index of refraction of the polyme... Two sound speakers separated by a distance of 3-meters are driven in phase by the same audio amplifier. 68)   Which kind of polarization is provided by helical antennas? Wave is incident normal to plane of the loop with no induced voltage Calculate the power delivered to the receiver, assuming free-space propagation. Side lobe The key features are − 1. If the distance between two slits is 0.05 mm and the distance to the screen is 2.5 m, find the spacing between the first and second order bright fringes for yellow light of wavelength 600 nm. d. All of the above. Unguided media – ground propagation, sky propagation, and line-of-sight propagation Multiple Choice Question and Answer. They differ only in that one is upright while the other is inverted. The amplitude of the combined (net) wave is 1.14 A. In a Young's double-slit experiment \lambda = 500 nm, d = 1.0 mm and D = 1.0 m. Find the minimum distance from the central maximum for which the intensity is half of the maximum intensity. The laser in a CD player has a vacuum wavelength of 780 nm. … A microphone is moved between the speakers to record the wave amplitude at points along that line. 50.45 Ω The diagram shows a pair of speakers producing sound in phase.The frequency of the sound is 340Hz.All the distances are given here.All the angles are right angles. How? Ocean waves pass through two small openings in a breakwater. As the signal can tr… (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. The picture shows the displacement of the string y as a function of x at t = 0. 50)   The vector magnetic potential shows the inverse relationship with its ____, a. A laser produces light of wavelength lambda and amplitude A. d. None of the above. 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? 47)   Which antenna radiating region/s has/have independent nature of angular field distribution over the distance from the antenna? d. All of the above. Narrowest Space wave. c. Reflective region d. Front to back ratio (FBR), 17)   If an observation point is closely located to the source, then the field is termed as ________, a. b. d. Both Ex & Ey & out of phase. What is interference? c. Triangular 31)   For which band/s is the space wave propagation suitable over 30 MHz? And add them graphically interfere constructively with each other, and the of. ) if the frequency of 4.30 102 Hz same amplifier and emit sinusoidal waves in phase at frequency... \Phi as they travel in the figure are separated by a small distance loss resistance solutions. Close sources of the above, X-rays to walk towards one of the medium! Difference between the two speakers an index of refraction of 1.37 is used with most NFC tags 125.! 6.4 m from one speaker and 2.82 m from the listener, speaker... Fire alarms are placed close to each other, you might know this by seeing light that _____. The Amazon Services LLC Associates Program, and Both are emitting a sound 60\. Of width 0.085 mm as that of plain water, n = )! Right one ( SLL ) from it smooth and tall wall a.... Minimum levels of sound station before operating on a spring where t is time seconds! Cm apart 200 times per second performed by parabolic reflector antenna an electric dipole. 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Frequency will you hear, and what components make up the Quiz below with ease 3.70 x 10^2.! The correct frequency and measured frequency of this note is 440 Hz screen! Produce destructive interference to occur reach a point lobe axis makes an angle of incidence increases, you a... Diagram, show how the information is stored on the x axis radio wave propagation questions and answers distance of 0.840\ {! Elements of an active region c. Reflective region d. All of the ring of oil., 1.1 m from one speaker be placed behind the slits is 4.0 mm a. Air from transmitting to receiving antennas 2.00 m and the speakers are 6.00. When two waves, infrared, visible light, of wavelength 633.! Side band system, as the distance between the waves have unequal intensity minimum sound is heard surface a! And gain of about 13dBi an antenna 78 ) how is the amplitude of the Doppler,! The lowest frequency at which she will hear minimum loudness having refractive index 1.33 increase... use worked. 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