Description : Tropospheric scatter is a method of sky wave propagation for which of the following frequency bands? A. 300 kHz to 3 MHz B. 3 MHz to 30 MHz C. 30 MHz to 300 MHz D. 300 MHz to 3 GHz
Last Answer : D. 300 MHz to 3 GHz
Description : The rhombic antenna is primarily used for A. ground wave propagation B. space wave propagation C. ionosphere scatter propagation D. sky wave propagation
Last Answer : D. sky wave propagation
Description : ECE Board Exam March 1996 When the transmitting and receiving antennas are in line-of-sight of each other, the mode of propagation is ________ wave. A. space or direct B. ground C. surface D. sky
Last Answer : A. space or direct
Description : Which propagation method is known as special case of skywave? A. Space wave B. Troposcatter C. Ground wave D. Direct wave
Last Answer : B. Troposcatter
Description : What propagation condition is usually indicated when a VHF signal is received from a station over 500 miles away? A. D-layer absorption B. Faraday rotation C. Tropospheric ducting D. Moonbounce
Last Answer : C. Tropospheric ducting
Description : What propagation condition is usually indicated when a VHF signal is received from a station over 5000 miles away? A. Moonbounce B. D-layer absorption C. Tropospheric ducting D. Faraday rotation
Description : Compare ground wave propagation. Sky wave propagation and space wave propagation.
Last Answer : Sr. N o Parameter Ground Wave Propagation Sky Wave Propagation Space wave Propagation 1 Frequency Range 30 kHz to 3 MHz 3 MHz to 30 MHz frequencies above 30 MHz 2 ... These waves have line of sight propagation, ... 6 Fading Problem less Severe Less
Description : Man-made noise is usually from _______. A. transmission over power lines and by ground wave B. sky-wave C. space-wave D. troposphere
Last Answer : A. transmission over power lines and by ground wave
Description : Which of the following is not one of the natural ways a radio wave may travel from transmitter to receiver? A. Ground wave B. Micro wave C. Sky wave D. Space wave
Last Answer : B. Micro wave
Description : Which of the following layers of the ionosphere has no effect on sky wave propagation during daytime? A. D B. E C. F1 D. F2
Last Answer : A. D
Description : To obtain the most reliable sky wave propagation the ____ should be used. A. Lowest useable frequency (LUF). B. Maximum useable frequency (MUF). C. Optimum useable frequency (OUF). D. Critical frequency
Last Answer : C. Optimum useable frequency (OUF).
Description : Which if the following layers of the ionosphere has no effect on sky wave propagation during the hours of darkness? A. D B. E C. F1 D. F2
Description : Which of the following frequency bands is best suited for sky wave propagation? A. 30 to 300 kHz B. 3 MHz to 30 MHz C. 30 MHz to 300 MHz D. 3 GHz to 30 GHz
Last Answer : B. 3 MHz to 30 MHz
Description : What is the metric subdivision of VHF band? A. Metric B. Millimetric C. Decimetric D. Centimetric
Last Answer : A. Metric
Description : Which of the following frequency bands is best suited for ground wave propagation? A. 30 to 300 kHz B. 300 kHz to 3 MHz C. 3 MHz to 30 MHz D. 30 MHz to 300 MHz
Last Answer : A. 30 to 300 kHz
Description : Compare ground wave and space wave propagation on the basis of: (i) Frequency range (ii) Method of propagation.
Last Answer : Compare ground wave and space wave propagation on the basis of: (i) Frequency range (ii) Method of propagation.
Description : What is the resultant field strength at the receiving antenna in space wave propagation under case 2? A. 0 B. ξd C. 2ξd D. 3ξd
Last Answer : C. 2ξd
Description : A means of beyond the line-of-sight propagation of microwave signal. A. Space wave B. Microwave link C. Troposcatter D. Point-to-point
Last Answer : C. Troposcatter
Description : Compare sky wave and space wave propagation w.r.t. following points. (i) Frequency range (ii) Effect of fading (iii)Polarization (iv)Application
Last Answer : Sr. No Parameters Sky Wave Propagation Space Wave Propagation 1 Frequency range 3 MHz to 30 MHz Above 30 MHz 2 Effect of fading Problem of fading is ... horizontally Polarized 4 Application RadioBroadcasting (SW Range) Used for TV and FM broadcasting
Description : The VLF and LF bauds use .............. propagation for communication. (A) Ground (B) Sky (C) Line of sight (D) Space
Last Answer : Answer: A Explanation: VLF (Very Low Frequency) LF (Low Frequency) In general there are three type of propagation.1.Ground Propagation 2.Sky propagation 3.Line-of-sight propagation ... portion of the atmosphere. These low-frequency signals travel in all directions from the transmitting antenna.
Description : Where is the tropospheric region that contributes most strongly to tropospheric scatter propagation?
Last Answer : Near the mid-point between the transmitting and receiving antennas, just above the radio horizon.
Description : Which radio frequency bands use the tropospheric scattering principle for propagation of radio waves?
Last Answer : Vhf and above
Description : Explain Tropospheric scatter propagation with sketch.
Last Answer : As the name implies, troposcatter uses the troposphere as the region that affects the radio signals being transmitted, returning them to Earth so that they can be received by the ... of "blurring" the overall received signal and this makes high speed data transmissions difficult.
Last Answer : Tropospheric mode of propagation is used in VHF.
Description : ____ is a term given to the region where superrefraction occurs. A. Strata B. Duct C. Isothermal region D. Tropospheric region
Last Answer : B. Duct
Description : What device measures the angle between two radio frequencies and also the direction of propagation of a wave? A. Densimeter B. Absorption wavemeter C. Goniometer D. Ergometer
Last Answer : C. Goniometer
Description : An electromagnetic wave is ________ polarized when the electric field lies wholly in one plane containing the direction of propagation. A. Horizontally B. Linearly C. Circularly D. Vertically
Last Answer : B. Linearly
Description : The total propagation delay time from transmission to reception of signals from a ground transmitter to ground receiver with angle of elevation at 10 degrees respectively is A. 273 ms B. 239 ms C. 275 ms D. 260 ms
Last Answer : A. 273 ms
Description : Distancesnearthe skip distance should beused forthe sky-wave propagation a. to avoid tilting b.topreventsky-wave andupper rayinterference c. to avoid the Faraday effect d. so as nor to exceed the critical frequency
Last Answer : b.topreventsky-wave andupper rayinterference
Description : Describe the effect of ionosphere on sky wave propagation.
Last Answer : The Ionosphere is the upper portion of the atmosphere. The ultra violet radiation from the sun will ionize the upper layer of the atmosphere. In this layer free electrons and positive and negative ions are ... layer. Its Frequency Range is from 3 MHz to 30 MHz Polarization: Vertical.
Description : Signals with a frequency between 2 MHz and 30 MHz use ______ propagation. A) ground B) sky C) line-of-sight D) none of the above
Last Answer : sky
Description : Signals with a frequency below 2 MHz use _______ propagation. A) ground B) sky C) line-of-sight D) none of the above
Last Answer : ground
Last Answer : The polarization required in ground wave propagation is vertical (linear).
Description : The antenna efficiency of an HF grounded vertical antenna can be made comparable to that of a half-wave antenna A. By installing a good ground radial system B. By isolating the coax shield from ground C. By shortening the vertical D. By lengthening the vertical
Last Answer : A. By installing a good ground radial system
Description : Which of the following terrain types permits a ground wave to travel the farthest? A. Salt water B. Fresh water C. Sandy D. Rocky
Last Answer : A. Salt water
Description : How can the antenna efficiency of an HF grounded vertical antenna be made comparable to that of a half-wave antenna? A. By lengthening the vertical B. By installing a good ground radial system C. By shortening the vertical D. By isolating the coax shield from ground
Last Answer : B. By installing a good ground radial system
Description : Ratio of the velocity of propagation of a light ray in free space to the velocity of propagation of a light ray in free space in a given material. ∙ A. refractive index ∙ B. standing wave ratio ∙ C. velocity factor ∙ D. propagation velocity
Last Answer : ∙ A. refractive index
Description : For a space wave transmission, the radio horizon distance of a receiving antenna with a height of 64 meters is approximately A. 8 km B. 32 km C. 64 km D. 256 km
Last Answer : B. 32 km
Description : Which of the following phenomena is possible is free space medium? A. Reflection of radio wave B. Diffraction of radio wave C. Refraction of radio wave D. Attenuation of radio wave
Last Answer : D. Attenuation of radio wave
Description : A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna. A. 36 meters high B. 64 meters high C. 100 meters high D. 182.25 meters high
Last Answer : A. 36 meters high
Description : If a transmitting antenna is 100 meters high and a separate receiving antenna is 64 meters high, what is the maximum space wave communication distance possible between them? A. 18 km B. 72 km C. 164 km D. 656 km
Last Answer : B. 72 km
Description : For a space wave transmission, the radio horizon distance of a transmitting antenna with a height of 100 meters is approximately: A. 10 km B. 40 km C. 100 km D. 400 km
Last Answer : B. 40 km
Description : Any small element of space in the path of a wave may be considered as a source of secondary wavelet. A. De Morgan’s Principle B. Faraday’s Law C. Huygen’s Principle D. Fresnel’s Law of optics
Last Answer : C. Huygen’s Principle
Description : Electromagnetic wave travel at __________ in free space. A. 300,000 km/sec B. 100,000 km/ sec C. 400,000 km/sec D. 200km/sec
Last Answer : A. 300,000 km/sec
Description : The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB
Last Answer : A. 403 dB
Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies a. Stripline b. Microstrip c. Laser beam d. Fiber optics
Last Answer : d. Fiber optics
Description : ________ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. a. Material dispersion b. Wavelength dispersion c. Modal dispersion d. Delay dispersion
Last Answer : c. Modal dispersion
Description : Dispersion is used to describe the a. Splitting of white light into its component colors b. Propagation of light in straight lines c. Bending of a beam of light when it goes from one medium to another d. Bending of a beam light when it strikes a mirror
Last Answer : a. Splitting of white light into its component colors
Description : What is the propagation delay when a signal is transmitter by an earth station to a geosynchronous satellite about 38,500 km above earth’s equator and then received by the same earth station? A. 256 msec B. 128 msec C. 300 msec D. 400 msec
Last Answer : A. 256 msec
Description : The round-trip propagation delay between two earth stations through a geosynchronous satellite is A. 500 to 600 ms B. 300 to 400 ms C. 600 to 700 ms D. 400 to 500 ms
Last Answer : A. 500 to 600 ms