Description : A radio communications service use in radio regulation between specified fixed points provided primarily for the safety of air navigation and for the regular efficient and economical air transport ... operation service B. Space service C. Aeronautical mobile service D. Aeronautical fixed service
Last Answer : D. Aeronautical fixed service
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 microwave communications system space loss calculation formula is A. 92.4 + 10 log f +20 log d B. 94.2 + 10 log f +20 log d C. 92.4 + 20 log f +20 log d D. 94.2 + 20 log f +20 log d
Last Answer : C. 92.4 + 20 log f +20 log d
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
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 illumination factor is normally considered in computing parabolic antenna gain in microwave communications? A. 0.54 B. 0.65 C. 0.75 D. 0.85
Last Answer : A. 0.54
Description : In telecommunications when we call data communications it means the transmission of________. A. Voice and video B. Voice C. Video D. Computer data
Last Answer : D. Computer data
Description : Rules governing the transmission of digital information. A. Line protocol B. Isochronous C. Data communications D. Digital communications
Last Answer : B. Isochronous
Description : RS-232, RS-449, RS-530, V, 24 and X.21 are examples of ____________. A. standards for interfaces between modems and transmission facilities B. standards for various types of ... for interfaces between terminals and modems D. standards for end to end performance of data communications system
Last Answer : C. standards for interfaces between terminals and modems
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 : ECE Board Exam March 1996 The K-factor under normal atmospheric conditions in a microwave radio data profile calculation is equal to ___________. A. 2/3 B. 0 C. 4/3 D. Infinity
Last Answer : C. 4/3
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 : 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 : Which of the following systems is not used in radio detection and ranging? A. Frequency shift B. Frequency modulation C. Pulse radar D. Amplitude modulation
Last Answer : D. Amplitude modulation
Description : RADAR means A. Radio detection and rating B. Radio detection and ranging C. Radio distance and ranging D. Radio delay and ranging
Last Answer : B. Radio detection and ranging
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 : A law that specifically requires the service of a duly registered electronics and communications engineer in the designing installation and construction, operation and maintenance of radio stations. A. Act 3846 B. LOl 1000 C. R.A. 5734 D. Dept. order 88
Last Answer : D. Dept. order 88
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 : The basic law providing for the regulation of radio station, communications in the Philippines and other purposes. A. Act. No.`3846 B. D.O. No. 11 C. D.O. No. 88 D. D.O. No. 5
Last Answer : A. Act. No.`3846
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 : A component that samples the microwave signal travelling in one direction down to the transmission line A. Isolator B. Combiner C. Directional coupler D. Attenuator
Last Answer : C. Directional coupler
Description : This type of transmission permits communication in the frequency range from 30 to 60 MHz and over distances from about 1000 to 2000 km. A. Troposcatter B. Ionospheric scatter C. Ducting D. Microwave
Last Answer : B. Ionospheric scatter
Description : Type of transmission path that permits communication in the frequency range from 30 to 60 MHz and over distances form about 1000 to 2000 km. A. Ducting B. Ionospheric scatter C. Microwave D. Troposcatter
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 : 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 : 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 : What is the free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz? A. 145.6 dB B. 138.5 dB C. 135.5 dB D. 140.89 dB
Last Answer : D. 140.89 dB
Description : A one-hop, full duplex, microwave system in a space diversity arrangement. Determine “how many receivers in all are used?” A. 8 B. 2 C. 4 D. 6
Last Answer : B. 2
Description : The most common device used as a light detector in fiber optic communications system. A. LED B. Darlington phototransistor C. APDs D. PIN diode
Last Answer : C. APDs
Description : Iridium satellites can provide data communications of up ____ bps data rate. A. 1200 B. 4800 C. 2400 D. 3840
Last Answer : C. 2400
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 : In what form does the information of data communications is transmitted between two points? A. Alphanumeric form B. Alphabetic form C. Numeric form D. Binary form
Last Answer : D. Binary form
Description : The primary purpose of the data modem is to A. interface analog terminal equipment to analog communications channel B. interface digital terminal equipment to analog communications ... to digital communications channel D. interface digital terminal equipment to digital communications channel
Last Answer : B. interface digital terminal equipment to analog communications channel
Description : The line control unit (LCU) operates on the data digital form. A. Data communications equipment (DCE) B. UART C. Modem D. Data terminal equipment (DTE)
Last Answer : D. Data terminal equipment (DTE)
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 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 : 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 : What is the first symbol of a radio signal transmission having an amplitude modulated signal carrier, double side band? A. C B. B C. H D. A
Last Answer : D. A
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 : A third symbol radio emission which represent telephone transmission including sound broadcasting. A. W B. F C. C D. E
Last Answer : D. E
Description : Term for the transmission of printed pictures by radio? A. Facsimile B. ACSSB C. Xerography D. Television
Last Answer : A. Facsimile
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 : 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 : 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 : What is the effect in over modulated amplitude modulated radio broadcasting transmission? A. Interference to adjacent channel B. Higher fidelity C. Increase noise D. Higher audio signal
Last Answer : A. Interference to adjacent channel
Description : A form of telecommunication for the transmission of transient images of fixed or moving objects. A. E-mail B. Television C. Radio D. Internet
Last Answer : B. Television
Description : Production of radiation by a radio transmitting station A. Monitoring B. Emission C. Radiation D. Transmission
Last Answer : B. Emission
Description : Referred by radio regulation as the station in the mobile service not intended to be used while in motion. A. Fixed station B. Base station C. Land station D. Coast station
Last Answer : C. Land station
Description : Which of the following is designated as the international distress, safety and calling frequency for radio telephony for stations of the maritime mobile service when using frequencies in the authorized bands between 156 and 174 MHz? A. 165.8 MHz B. 156.8 MHz C. 158.6 MHz D. 168.5 MHz
Last Answer : B. 156.8 MHz
Description : A radio land station in the land mobile service A. Mobile station B. Land station C. Base station D. Ship earth station
Last Answer : C. Base station