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 : Circuit used to amplify the optical signal in fiber optics communications links. A. Attenuator B. Optical repeater C. Optical amplifier D. Generator
Last Answer : B. Optical repeater
Description : Designed to receive a signal from a transmitting station on the ground and retransmit it to a receiving station located elsewhere A. Communication satellite B. Repeater C. Relay station D. Transponder
Last Answer : A. Communication satellite
Description : Essentially a satellite ___________ is a radio repeater in the sky A. transponder B. comparator C. duplexer D. billboard
Last Answer : A. transponder
Description : Which does not use vertical polarization antenna? A. AM Broadcasting B. FM Broadcasting C. Mobile Communications D. Satellite Communications
Last Answer : B. FM Broadcasting
Description : Which of the following is the most common application of satellite? A. Surveillance B. Military application C. Communications D. Newscasting
Last Answer : C. Communications
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 : The satellite communications channels in a transponder are defined by the A. LNA B. bandpass filter C. mixer D. input signals
Last Answer : B. bandpass filter
Description : The satellite subsystem that monitors and controls the satellite is the A. propulsion subsystem B. power subsystem C. communications subsystem D. telemetry, tracking, and command subsystem
Last Answer : D. telemetry, tracking, and command subsystem
Description : The key electronic component in a communications satellite is the A. telemetry equipment B. on-board computer C. command and control system D. transponder
Last Answer : D. transponder
Description : The frequency of Ku band for satellite communications. A. 6/4 GHz B. 14/11 GHz C. 12/14 GHz D. 4/8 GHz
Last Answer : B. 14/11 GHz
Description : How does spatial isolation technique in satellite communications avoid interference? A. Use of different polarity antennas B. Use of different types of antennas C. Employment of highly directional spot-beam antennas D. Use of low gain antennas
Last Answer : C. Employment of highly directional spot-beam antennas
Description : In satellite communications, what means of attitude control is using the angular momentum of the spinning body to provide the roll and yaw stabilization? A. Spin stabilization B. Radial stabilization C. Three-axis stabilization D. Station keeping
Last Answer : A. Spin stabilization
Description : What satellite subsystem monitors onboard conditions such as temperature and battery voltage and transmits this data back to a ground station for analysis? A. Communications subsystem B. AKM C. TTC D. Transponder
Last Answer : C. TTC
Description : What is the current frequency band given most attenuation for satellite communications? A. Ku B. C band C. J D. P
Last Answer : A. Ku
Description : What is the quardband between transponder channels in the commercial C-band for satellite communications? A. 6 MHz B. 36 MHz C. 4 MHz D. 2 MHz
Last Answer : C. 4 MHz
Description : One of the first satellite system catering personal based communications services scheduled for operation. A. Iridium system B. Plutonium system C. Indium system D. Gallium system
Last Answer : A. Iridium system
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 : Which of the following improves antenna directivity? A. Driven element B. Reflector element C. Director element D. Parasitic element
Last Answer : D. Parasitic element
Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24
Last Answer : B. 2.6
Description : Known as the technique for adding a series inductor at or near the center of an antenna element in order to cancel the capacitive reactance of an antenna. A. Dipole B. Center loading C. Reflector D. loading coil
Last Answer : D. loading coil
Description : The reflector and director of an antenna array are considered as A. Parasitic elements B. Transcendental elements C. Feed-points D. Driven elements
Last Answer : A. Parasitic elements
Description : A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 ... ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6
Last Answer : D. 2.6
Description : A type of array antenna which consists of one half-wave driven dipole, one reflector and one director A. Hertzian dipole B. Yagi-uda C. Broadside collinear D. Log periodic dipole array
Last Answer : B. Yagi-uda
Description : A form of regenerative repeater for transmitting signals over a long cable received through a relay in a clearer form. A. Active generator B. Active repeater C. Interpolator D. Audio generator
Last Answer : C. Interpolator
Description : What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W
Last Answer : A. 317 W
Description : What is the effective radiated power of a repeater with 120 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 601 W B. 240 W C. 60 W D. 379 W
Last Answer : C. 60 W
Description : What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 800 W B. 126 W C. 12.5 W D. 1260 W
Last Answer : B. 126 W
Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 37.6 W B. 237 W C. 150 W D. 23.7 W
Last Answer : A. 37.6 W
Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain? A. 600 W B. 75 W C. 18.75 W D. 150 W
Last Answer : D. 150 W
Description : What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain? A. 300 W B. 315 W C. 31.5 W D. 69.9 W
Last Answer : C. 31.5 W
Description : What is the effective radiated power of a repeater with 50 watts transmitter power output \, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain? A. 158 W B. 39.7 W C. 251 W D. 69.9 W
Last Answer : B. 39.7 W
Description : A microwave system that requires the use of repeater. A. Intervening terrain is favorable B. Distances involved are greater C. The required reliability is met D. All of these
Last Answer : B. Distances involved are greater
Description : A microwave system that requires the use of repeater. A. Intervening terrain is favorable B. Distances involved are greater C. The required reliability is met
Description : The main benefit of light-wave communications over microwaves or any other communications media is a. Lower cost b. Better security c. Wider bandwidth d. Freedom from interference
Last Answer : c. Wider bandwidth
Description : What is the main purpose of a communications system? A. None of these B. To have a frequency assignment C. For modulation D. To provide an acceptable replica of the information at the destination
Last Answer : D. To provide an acceptable replica of the information at the destination
Description : What is the function of Earth observation satellite ?
Last Answer : The work of the earth observation satellite is to observe the oil spill for the ship at sea.
Last Answer : A communication satellite is a repeater between many transmitting stations and many receiving stations.
Description : Pick up the correct statement from the following: (A) In remote sensing technique, the observation place, is called a platform (B) Platforms may be either stationary or mobile (C) Spatial resolution of the imaging system becomes poorer with increase of platform height (D) All of these
Last Answer : Answer: Option D
Description : The main power sources for a satellite are A. batteries B. solar cells C. fuel cells D. thermoelectric generators 58. The maximum height of an ellip
Last Answer : B. solar cells
Description : Which of the following is used as an optical receiver in fiber optics communications a. APD b. Tunnel diode c. Laser diode d. LED
Last Answer : a. APD
Description : Which of the following is used as an optical transmitter on the Fiber Optical Communications? a. APD b. LSA diode c. PIN diode d. LED
Last Answer : d. LED
Description : Is a non-coherent light source foe optical communications system. a. ILD b. LED c. APD d. PIN Diode
Last Answer : b. LED
Description : Repeaters inside communications satellites are known as A. Trancievers B. Transponders C. Transducers D. TWT
Last Answer : B. Transponders
Description : Name one or more sources of noise bearing on electronic communications. A. Steam boiler B. Galaxies C. Internal combustion engine D. Both B and C
Last Answer : D. Both B and C
Description : A large emission of hydrogen from the sun that affects communications. A. Solar flare B. Cosmic disturbance C. Ballistic disturbance D. Solar noise
Last Answer : A. Solar flare
Description : Is the interference coming from other communications channels? A. Jitter B. Crosstalk C. RFI D. EMI
Last Answer : B. Crosstalk
Description : Noise always affects the signal in a communications systems at the ________. A. transmitter B. channel C. information source D. destination
Last Answer : B. channel
Description : Which of the following frequencies is normally used for distress and safety communications? A. 4209.5 kHz B. 490 kHz C. 518 kHz D. 2174.5 kHz
Last Answer : D. 2174.5 kHz
Description : What is the common up-converter and down-converter IF for microwave communications? A. 60 MHz B. 80 MHz C. 120 MHz D. 70 MHz
Last Answer : D. 70 MHz