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 : Most commercial satellite activity occurs in which band(s)? A. L B. C and Ku C. X D. S and P
Last Answer : B. C and Ku
Description : A band where most military satellite often operate A. Ku B. C C. X D. L
Last Answer : C. X
Description : The Ku-band in the satellite service A. 14/11 GHz B. 30/17 GHz C. 8/7 GHz D. 6/4 GHz
Last Answer : A. 14/11 GHz
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 Ku frequency band used in satellite communication (for uplink and downlink) is: (1) 14 GHz and 11 GHz (2) 30 GHz and 20 GHz (3) 70 GHz and 50 GHz (4) 60 GHz and 45 GHz
Last Answer : The Ku frequency band used in satellite communication (for uplink and downlink) is: 14 GHz and 11 GHz
Description : For navigation as well as marine and aeronautical communications and radar, ____ band is used. A. L B. K C. S D. J
Last Answer : A. L
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 : What band does VSAT first operate? A. L-band B. X-band C. C-band D. Ku-band
Last Answer : C. C-band
Description : What band of frequencies do these satellites operate? A. L band B. Ka band C. C band D. Ku band
Last Answer : A. L band
Description : Which of the following are uplinks in the Ku band? A. 14 to 14.5 GHz B. 11.7 to 12.2 GHz C. 14 to 15.5 GHz D. 11 to 11.5 GHz
Last Answer : A. 14 to 14.5 GHz
Description : A band whereloften operate A. Ku B. C C. X D. L
Description : What band does VSAT first operate? A. X-band B. C-band C. Ku-band D. L-band
Last Answer : B. C-band
Description : The bandwidth of C-band satellite frequency band in U.S. A. 500 GHz B. 1000 GHz C. 1000 MHz D. 500 MHz
Last Answer : D. 500 MHz
Description : What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz
Last Answer : C. 2225 MHz
Description : Highest frequency that can be used for skywave HF communications between two given points on earth. A. Gyro frequency B. Maximum usable frequency C. Critical frequency D. Virtual frequency
Last Answer : B. Maximum usable frequency
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 : 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 main function of a communications satellite is a/ an A. repeater B. reflector C. beacon D. observation platform
Last Answer : A. repeater
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 : 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 : 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 : 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 : What is the required quality factor for an SSB filter with the following data: center frequency= 1 MHz, the desired attenuation level of the unwanted sideband= 80 dB and the separation between sidebands= 200 Hz? A. 1,250 B. 12,500 C. 125,000 D. 25,000
Last Answer : C. 125,000
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 frequency does oxygen causes excessive attenuation A. 119 GHz B. 183 GHz C. 310 GHz D. 60 GHz
Last Answer : D. 60 GHz
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 : _______ 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 : 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 the frequency range of an aircraft’s Very High Frequency (VHF) communications? A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz) B. 108.000 MHz to 117.95 MHz C. 329.15 MHz to 335.00 MHz D. 2.0000 MHz to 29.999 MHz
Last Answer : A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz)
Description : What term is used to describe a spread spectrum communications system in which a very fast binary bit stream is used to shift the phase of an RF carrier? A. Frequency hopping B. Direct sequence C. Binary phase-shift keying D. Phase compandored spread spectrum
Last Answer : B. Direct sequence
Description : What is the term used to describe a spread spectrum communications system where the center frequency if a conventional carrier is altered many time per second in accordance with a pseudo ... hopping B. Direct sequence C. Time-domain frequency modulation D. Frequency compandored spread spectrum
Last Answer : A. Frequency hopping
Description : In radio High frequency communications the higher the radio frequency the ______. A. Higher it can reach B. Shorter it can reach C. Effect is null D. Longer it can reach
Last Answer : D. Longer it can reach
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 : A method of multiple accessing where a given RF channel bandwidth is divided inot smaller frequency band. A. CDMA B. ANIK-D C. TDMA D. FDMA
Last Answer : D. FDMA
Description : What is the typical bandwidth of a satellite band? A. 36 MHz B. 40 MHz C. 70 MHz D. 500 MHz
Description : Bluetooth operates in which band? a) Ka Band b) L Band c) Ku Band d) 2.4 GHz ISM Band
Last Answer : d) 2.4 GHz ISM Band
Description : The upper pulse rate and information carrying capacity of a cable is limited by a. Pulse shortening b. Attenuation c. Light leakage d. Modal dispersion
Last Answer : d. Modal dispersion
Description : Which of the cable length has the highest attenuation? a. 1 km b. 2 km c. 95 ft d. 5500 ft
Last Answer : b. 2 km
Description : Cable attenuation is usually expressed in terms of a. Loss per foot b. dB/km c. intensity per mile d. voltage drop per inch
Last Answer : b. dB/km
Description : The loss in signal power as light travels down a fiber is called a. Dispersion b. Scattering c. Absorption d. Attenuation
Last Answer : d. Attenuation
Description : _________ is the random and unpredictable electric signals from natural causes, both internal and external to the system. A. Interference B. Attenuation C. Distortion D. Noise
Last Answer : D. Noise
Description : Atmospheric attenuation is an attenuation which is due to A. mist and fog B. gasses in the atmosphere C. water vapor and oxygen D. rain
Last Answer : C. water vapor and oxygen
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 : The presence of standing waves on a transmission line is the result of A. a high level of attenuation on the line. B. terminating the line by a resistive load equal in value to the surge impedance ... input power to below its critical level. D. an impedance mismatch between the load and the line.
Last Answer : D. an impedance mismatch between the load and the line.