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 : 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 : How far away is the radio horizon of an antenna 100ft high? A. 14.14 mi B. 40km C. 14.14 km D. 40 mi
Last Answer : A. 14.14 mi
Description : What is a selective fading effect? A. A fading effect caused by small changes in beam heading at the receiving station. B. A fading effect caused by phase differences between radio wave ... station D. A fading effect caused by time differences between the receiving and transmitting stations.
Last Answer : B. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.
Description : What is the major cause of selective fading? A. Small changes in the beam heading at the receiving station. B. Large changes in the height of the ionosphere, as experience at the ... Phase differences between radio wave components of the same transmission, as experienced at the receiving station.
Last Answer : D. Phase differences between radio wave components of the same transmission, as experienced at the receiving station.
Description : Refers to an effect of selective fading. A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station. B. A fading ... caused by large changes in the height of the ionosphere, as experienced at the receiving station.
Last Answer : A. A fading effect caused by phase differences between radio wave components of the same transmission, as experienced at the receiving station.
Description : The angle of elevation of the antenna beam is 20°. Calculate the transmission-path distance for an ionospheric transmission that utilizes a layer of virtual height 200 km. Use flat-earth approximation. A. 966 km B. 2100 km C. 1100 km D. 405 km
Last Answer : C. 1100 km
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 : Consider a source computer(S) transmitting a file of size 106 bits to a destination computer (D)over a network of two routers (R1 and R2) and three links(L1, L2, and L3). L1connects S to R1; L2 connects R1 to ... file from S to D? a. 1005 ms b. 1010 ms c. 3000 ms d. 3003 ms Answer: Option(a)
Last Answer : a. 1005 ms
Description : A radio communications link is to be established via the ionosphere. The maximum virtual height of the layer is 100 km at the midpoint of the path and the critical frequency is 2 MHz. The distance between stations is 600 ... optimum working frequency? A. 6.32 MHz B. 2.1 MHz C. 5.4 MHz D. 1.8 MHz
Last Answer : C. 5.4 MHz
Description : What is a dummy antenna? A. One which is used as a reference for gain measurements B. And antenna used for hand-held radio C. An non-directional transmitting antenna D. A non-radiating load for a transmitter used for testing
Last Answer : D. A non-radiating load for a transmitter used for testing
Description : Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW
Last Answer : A. 0.871 μW
Description : ECE Board Exam March 1996 What is the transmission rate of a system for transmitting the output of a microcomputer to a line printer operating at a speed of 30 lines/minute? Assume that the line printer has 8 bits ... and prints out 80 characters/line. A. 800 bps B. 400 bps C. 320 bps D. 640 bps
Last Answer : C. 320 bps
Description : What type of transmission is radiated from an aircraft’s radio altimeter antenna? A. An amplitude modulated continuous wave B. A pulse position modulated UHF signal C. A differential phase shift keyed UHF signal D. A frequency modulated continuous wave
Last Answer : D. A frequency modulated continuous wave
Description : Production of radiation by a radio transmitting station A. Monitoring B. Emission C. Radiation D. Transmission
Last Answer : B. Emission
Description : What phenomenon causes the radio-path horizon distance to exceed the geometric horizon? A. Diffraction B. Ducting C. Reflection D. Refraction
Last Answer : D. Refraction
Description : What phenomenon causes the radio-path horizon distance to exceed the geometric horizon? A. E-layer skip. B. D-layer skip. C. Auroral skip. D. Radio waves may be bent.
Last Answer : D. Radio waves may be bent.
Description : Space diversity transmission means transmitting and receiving on _______. A. Two or more antennas operating on two different frequencies B. Two or more identical frequencies C. Two or more antennas operating on the same frequency D. Two or more different frequency
Last Answer : C. Two or more antennas operating on the same frequency
Description : Space diversity transmission means transmitting and receiving on A. two or more antennas operating on two different frequencies B. two or more identical frequencies C. two or more different frequencies D. two or more antennas operating on the same frequencies
Last Answer : D. two or more antennas operating on the same frequencies
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 : When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB? A. 196 dB B. 200 dB C. 150 dB D. 100 dB
Last Answer : A. 196 dB
Description : During the night when the F2 layer combines with F1 layer it falls to what approximate height? A. 250 km B. 350 km C. 300 km D. 400 km
Last Answer : C. 300 km
Description : Stacking elements in a transmitting antenna system A. increases the field strength at the receiving antenna B. increases the directivity of the transmitter antenna C. decrease the size of the lobe in the radiation pattern D. both A and B
Last Answer : D. both A and B
Description : What is the maximum line-of-sight distance between a paging antenna 250 ft high and a pager receiver 3.5ft of the ground? A. 25 km B.25mi C. 70.73 km D. 70.73 mi
Last Answer : B.25mi
Description : The polarization of a radio wave: A. Is perpendicular to the electrostatic field of the antenna B. Is the same direction as the electrostatic field of the antenna. C. Is the same direction ... field of the antenna. D. Is perpendicular to both the electrostatic and magnetic fields of the antenna.
Last Answer : B. Is the same direction as the electrostatic field of the antenna.
Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power
Last Answer : C. Mean power
Description : Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave? A. AF amplifier B. Antenna C. Detector D. Crystal
Last Answer : B. Antenna
Description : Referred to as an average power from the radio transmitter supplied to the antenna transmission line taken during one radio frequency cycle under no modulation. A. Carrier power B. Rated power C. Peak envelop power D. Mean power
Last Answer : A. Carrier power
Description : Radio wave concentration in the direction of the signal emitted by a directional antenna. A. Back lobe radiation B. Side lobe radiation C. Major lobe radiation D. Transmitted signal
Last Answer : C. Major lobe radiation
Description : Average power of a radio transmitter supplied to the antenna transmission line by a transmitter during one radio frequency cycle taken under the condition of no modulation. A. Peak envelop power B. Rated power C. Carrier power D. Mean power
Last Answer : C. Carrier power
Description : Factors that determine the radiation resistance of an antenna A. Transmission line length and height of antenna B. The location of the antenna with respect to nearby objects C. It is a constant for all antennas since it is physical D. Sunspot activity and the time of day
Last Answer : B. The location of the antenna with respect to nearby objects
Description : The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts
Last Answer : B. 158 watts
Description : An object on the top of a hill 100 m high is just visible above the horizon from a station at sea level. The distance between the station and the object is : (a) 38.53 km (b) 3.853 km (c) 3853 km (d) 385.3 km
Last Answer : (a) 38.53 km
Description : The conversion of digital signal into analog for purposes of transmitting into the telephone line is done through ______. A. ISDN B. Radio C. RS232C D. Modem
Last Answer : D. Modem
Description : ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste
Last Answer : B. Communications satellite
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 : 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 : What is included in the total resistance of an antenna system? A. Radiation resistance plus space impedance B. Radiation resistance plus transmission resistance C. Transmission line resistance plus radiation resistance D. Radiation resistance plus ohmic resistance
Last Answer : D. Radiation resistance plus ohmic resistance
Description : If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts
Last Answer : D. 6 watts
Description : In radio-communication, the signals emitted by transmitting antenna are reflected on – (1) stratosphere (2) ozonosphere (3) ionosphere (4) troposphere
Last Answer : (3) ionosphere Explanation: The lower atmosphere is more or less transparent to radio waves. However, the ionosphere reflects back the radio waves. Thus, a signal emitted by an antenna from a ... on the surface of Earth in the following two ways: ground wave propagation and sky wave propagation.
Description : In Radio Communication, the signals emitted by transmitting antenna are reflected on
Last Answer : Ionosphere
Description : In radio-communication, the signals emitted by transmitting antenna are reflected on (1) stratosphere(2) ozonosphere (3) ionosphere (4) troposphere
Last Answer : ionosphere
Description : If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to _______. (1) 300 m (2) 30 m (3) 3 m (4) 0.3 m
Last Answer : (1) 300 m Explanation: h = 3 × 108/106 = 300 m
Description : A wave with a wavelength of 40 meters and a height of 2 meters will NOT be refracted in water with a depth of more than: w) 1 meter x) 2 meters y) 10 meters z) 20 meters
Last Answer : ANSWER: Z -- 20 METERS
Description : A client-server system uses a satellite network, with the satellite at a height of 40,000 kms. What is the best-case delay in response to a request? (Note that the speed of light in air is 3,00,000 km/second). (A) 133.33 m sec (B) 266.67 m sec (C) 400.00 m sec (D) 533.33 m sec
Last Answer : (D) 533.33 m sec Explanation: The request has to go up and down, and the response has to go up and down. The total path length traversed is thus 160.000 km. The speed of light in air and vacuum is 300,000 km/sec, so the propagation delay alone is 160,000/300,000 sec or about 533 msec.
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 : 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 is not a common microwave application? A. Radar B. Data transmission C. Space communications D. Mobile radio
Last Answer : D. Mobile radio
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