Description : What is the delay time for satellite transmission from earth transmitter to earth receiver? A. 0.5 s B. 1.0 s C. 5 ms D. 0.25 ms
Last Answer : A. 0.5 s
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 : 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
Description : The maximum propagation delay of a geostationary satellite is A. 278 ms B. 239 ms C. 300 ms D. 250 ms
Last Answer : A. 278 ms
Description : What is the minimum propagation delay of a geostationary satellite? A. 278 ms B. 239 ms C. 300 ms D. 600 ms
Last Answer : B. 239 ms
Description : A satellite transmitter operates at 4GHz with an antenna gain of 4dBi. The receiver 40000 km away has an antenna gain of 50 dBi. If the transmitter has a power of 8 W, find (ignoring feedline losses and mismatch) the EIRP in dBW. A. 50 B. 69 C. 49 D. 30
Last Answer : C. 49
Description : The signal path from satellite to earth-based receiver. A. Downlink signal B. Uplink signal C. Incident signal D. Reflected signal
Last Answer : A. Downlink signal
Description : What satellite system parameter represents the quality of a satellite or an earth station receiver? A. Gain-to-Equivalent Noise Temperature Ratio (G/Te) B. Energy of Bit-to-Noise Density Ratio (Eb/No) C. Carrier-to-Noise Density Ratio (C/No) D. Bit energy
Last Answer : A. Gain-to-Equivalent Noise Temperature Ratio (G/Te)
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 : A ground station is operating to a geostationary satellite at a 5° angle of elevation. Calculate the round-trip time between ground station and satellite. A. 275 s B. 275 ms C. 137.5 s D. 137.5 ms
Last Answer : B. 275 ms
Description : What limits the sensitivity of a receiver? A. The power supply of the receiver B. The power output of a transmitter C. The noise floor of the receiver D. The distance between the transmitter and receiver
Last Answer : C. The noise floor of the receiver
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 : What is the uplink receiver frequency if the downlink transmitter is on channel 4 (3.84 Ghz)? A. 6.065 GHz B. 6.84 GHz C. 6.65 GHz D. 6.05 GHz
Last Answer : A. 6.065 GHz
Description : What is the path attenuation between transmitter and receiver at a frequency of 1.2 Ghz and a distance of 11,000 mi? A. 119 dB B. 115dB C. 179dB D. 174dB
Last Answer : C. 179dB
Description : What is the device used in fiber optic communication which consist of a receiver transmitter use to clean up and amplify digital data moving in one direction and another in the opposite direction? A. Optic compressors B. Optic retarders C. Optic isolator D. Optic regenerators
Last Answer : D. Optic regenerators
Description : Who is responsible in the correctness and accuracy of transmitted information content over a data communication? A. The channel B. The transmitter and receiver C. The modem D. The bridge
Last Answer : B. The transmitter and receiver
Description : Main basic components of a data communication are composed of the following. A. Computer, modern and router B. Computer, bridge and gateway C. Transmitter, channel and receiver D. Transmitter, computer and modem
Last Answer : C. Transmitter, channel and receiver
Description : How can receiver desensitizing be reduced? A. Increase the receiver bandwidth B. Ensure good RF shielding between the transmitter and receiver C. Increase the transmitter audio gain D. Decrease the receiver squelch, gain.
Last Answer : D. Decrease the receiver squelch, gain.
Description : Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna. A. Isolator B. Circulator C. Coupler D. Diode.
Last Answer : B. Circulator
Description : ______ is the first component of any MATV system to received broadcast signals. A. Receiver B. Antenna C. Filter D. Transmitter
Last Answer : B. Antenna
Description : ECE Board Exam March 1996 The capture area of an antenna is directly proportional to the A. frequency of the received signal B. distance between transmitter and receiver C. gain of the antenna D. power density of the signal
Last Answer : C. gain of the antenna
Description : _________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency. A. Horn antenna B. LNA C. Satellite receiver D. Satellite dish
Last Answer : B. LNA
Description : Which of the following is the basic component of a communications satellite receiver? A. On-board computer B. Reflector C. Telemetry D. Transponder
Last Answer : D. Transponder
Description : What do you call the single booster installed on the antenna dish of satellite receiver? A. Low noise amplifier B. Single amplifier C. Noise amplifier D. Rectifier
Last Answer : A. Low noise amplifier
Description : Receives and collects satellite signals form a broadcast satellite. A. LNB B. Yagi-Uda array C. Satellite receiver D. Satellite disk
Last Answer : D. Satellite disk
Description : _______ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency. A. Feedhorn B. Satellite dish C. Satellite receiver D. LNB
Last Answer : D. LNB
Description : Collects very weak signal from a broadcast satellite A. Satellite dish B. LNB C. Yagi-Uda antenna D. Satellite receiver
Last Answer : A. Satellite dish
Description : In cellular system, _____ defines the geographic distance that is required between cells using identical frequencies in order to avoid interference between the radio transmissions at these cells. A. frequency-reuse ratio B. distance-to-reuse ratio (D/R) C. reuse format plan ratio D. reuse factor
Last Answer : B. distance-to-reuse ratio (D/R)
Description : A final amplifier of a radio transmitter draws 250 mA of plate current when the plate supply voltage is 1400 volts. If the plate circuit efficiency is 80% and the transmitter is connected to an antenna having a feed impedance of 70 ohms, ... at the feed-point? A. 4.0 A B. 2.2 A C. 1.25 A D. 2.0 A
Last Answer : D. 2.0 A
Description : What is the phase delay of an 800 Hz voice signal if the phase shift is 15 degrees? A. 1.25 µsec B. 52 µsec C. 83.33 µsec D. 26 µsec
Last Answer : B. 52 µsec
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 : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303
Last Answer : A. 30.3
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 : 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 : Calculate the reverberation time of a living room 8 ft high, 13 ft wide and 20 ft long. The total absorption of the building structure inside the room is 180.7 sabines with four persons present in the room. A. 0.5 ms B. 0.05 s C. 0.5 s D. 5 ms
Last Answer : C. 0.5 s
Description : What is the free space attenuation of a satellite communications system operating at 36,000 km above the earth at 5.0 GHz? A. 198 dB B. 202 dB C. 142 dB D. 138 dB
Last Answer : A. 198 dB
Description : Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or ... under test, both working at the same temperature over the same bandwidth and fed from the same source
Last Answer : C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals
Description : What is the time delay introduced by a 75-ft coaxial cable with a dielectric constant of 2.3? A. 1.54 ns B. 11.5 ns C. 115.6 ns D. 1156 ns
Last Answer : C. 115.6 ns
Description : The front-end of a television receiver, having a bandwidth of 7Mhz, and operating at a temperature of 27˚C , consists of an amplifier having a gain of 15 followed by a mixer whose gain is 20. The ... equivalent noise resistance for this television receiver. A. 8760 Ω B. 875Ω C. 8.76Ω D. 0.876Ω
Last Answer : B. 875Ω
Description : What is transit time (time delay) of a 50-ft length transmission line of the above problem? A. 50 ns B. 100 ns C. 75 ns D. 65 ns
Last Answer : C. 75 ns
Description : What do you call the phenomenon in digital circuits that describe the duration of time a digital signal passes a circuit? A. Transmission time B. Elapsed time C. Propagation delay D. Travel delay
Last Answer : C. Propagation delay
Description : How would one squeeze more channels of communication into TDM frames of standard length? A. Shorten the time delay for each channel B. Raise the amplitude C. Add modulators D. Remove the synchronizing pulses
Last Answer : A. Shorten the time delay for each channel
Description : Refers to the satellite orientation with respect to the earth A. Satellite altitude B. Satellite position C. Satellite location D. Satellite orbit
Last Answer : A. Satellite altitude
Description : The signal path from earth station satellite A. Uplink signal B. Reflected signal C. Incident signal D. Downlink signal
Last Answer : A. Uplink signal
Description : Satellite the orbits in a circular pattern with an angular velocity equal to that of the earth A. Geostationary B. Early Bird I C. Syncorn I D. Stationary satellite
Last Answer : A. Geostationary
Description : The physical location of a satellite is determined by its A. distance from the earth B. latitude and longitude C. reference to the stars D. position relative to the sun
Last Answer : B. latitude and longitude
Description : How can multiple earth stations share a satellite on the same frequencies? A. Frequency reuse B. Multiplexing C. Mixing D. Frequency hopping
Last Answer : A. Frequency reuse
Description : The jet thrusters are usually fired to A. maintain altitude B. put the satellite into the transfer orbit C. inject the satellite in the geosynchronous orbit D. bring the satellite back to earth.
Last Answer : A. maintain altitude
Description : A satellite cross-link means A. Earth-to-satellite link B. Satellite-to-earth link C. Satellite-to-satellite link D. None of these
Last Answer : C. Satellite-to-satellite link