Description : Which of the following is not usually a part of a transponder are defined by the A. LNA B. Mixer C. Modulator D. HPA
Last Answer : C. Modulator
Description : A device that radiates electromagnetic energy and or intercepts electromagnetic radation. A. Antenna B. Transmitter C. Transmission line D. Transceiver
Last Answer : A. Antenna
Description : The voltage at the reference electrode of the circuit shown in the illustration is applied to the input of a/an ______________. EL-0090 A. class A detector whose output drives an ... drives an 2-stage isolation transformer D. magnetic amplifier whose output controls a saturable reactor
Last Answer : Answer: D
Description : In communication satellite, multiple repeaters are known as a. detector b. modulator c. stations d. transponders
Last Answer : transponders
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 : 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 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 : A satellite signal transmitted from a satellite transponder to earth’s station. A. Uplink B. Downlink C. Terrestrial D. Earthbound
Last Answer : B. Downlink
Description : What is the first passive satellite transponder? A. Sun B. Early Bird C. Score D. Moon
Last Answer : B. Early Bird
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 is the data rate in Mbps of a single satellite transponder considering an S/N of 30 dB? A. 35.8 B. 3.58 C. 358 D. 3580
Last Answer : C. 358
Description : Which of the following satellite subsystem provides stabilization in orbit and senses changes in orientation? A. Attitude control subsystem B. TTC C. AKM D. Transponder
Last Answer : A. Attitude control subsystem
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 : How many transponder channels are realized in the commercial C-band without frequency re-use? A. 24 B. 12 C. 36 D. 48
Last Answer : B. 12
Description : What is the typical satellite transponder bandwidth? A. 24 MHz B. 500 MHz C. 36 MHz D. 48 MHz
Last Answer : C. 36 MHz
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 is the maximum theoretical data rate of the above problem if one transponder is used for binary transmission? A. 36 Mbps B. 72 Mbps C.18 Mbps D. 144 Mbps
Last Answer : B. 72 Mbps
Description : Known as the satellite transmitted signal form a satellite transponder to earth’s station. A. Uplink B. Down link C. RHCP D. Vertically polarized
Last Answer : B. Down link
Description : The first passive satellite transponder. A. Early bird B. Score C. Moon D. Sputnik
Last Answer : C. Moon
Description : Satellite signal transmitted from a satellite transponder to earth’s station. A. Vertically polarized B. Uplink C. Downlink D. RHCP
Last Answer : C. Downlink
Description : Which circuit detects frequency modulated signal? A. Modulator B. Discriminator C. Demodulator D. Modem
Last Answer : B. Discriminator
Description : What do you call a circuit that controls the magnetron output? A. Inverter B. Impeller C. Modulator D. Converter
Description : The output of a balanced modulator is ____________. A. LSB and USB B. LSB C. USB D. Carrier
Last Answer : A. LSB and USB
Description : A source code whose average word length approaches the fundamental limit set by the entropy of a discrete memoryless source. A. Prefix code B. Huffman code C. Entropy code D. Source code
Last Answer : B. Huffman code
Description : Mention the advantages of integrated circuits over discrete components.
Last Answer : *Miniaturisation and hence increased equipment density. *Cost reduction due to batch processing. *Increased system reliability due to the elimination of soldered joints. *Improved functional performance. *Matched devices. *Increased operating speeds. *Reduction in power consumption.
Description : The _____ houses the switches in token ring. A. transceiver B. nine-pin connector C. MAU D. NIC E. None of the above
Last Answer : MAU
Description : What is a device that detects both vertically and horizontally polarized signals simultaneously? A. Orthomode transducer B. Crystal detector C. Optoisolator D. Isomode detector
Last Answer : A. Orthomode transducer
Description : A particular circuit that rids FM of noise A. Detector B. Discriminator C. Phase Shifter D. Limiter
Last Answer : D. Limiter
Description : What part or section of a TV receiver that separates the sound and video signals? A. IF stage B. Video amplifier C. Video detector D. Burst separator
Last Answer : C. Video detector
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 : What kind of effect is referred to a varying light producing a varying voltage output of a detector? A. Current effect B. Voltage effect C. Resistive effect D. Photovoltaic effect
Last Answer : D. Photovoltaic effect
Description : A figure of merit used to measure the performance of a radiation detector. A. Noise equivalent power B. Ripple factor C. Safe factor D. Quality factor
Last Answer : A. Noise equivalent power
Description : If a fiber optic system has a rise time of 38.55 ns, the source rise time is 12 ns and the detector rise time is 12 ns, what is the cable rise time? A. 34.61 ns B. 14.55 ns C. 52.55 ns D. 26.25 ns
Last Answer : A. 34.61 ns
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 : If a fiber optic system has a rise time of 16 ns, the source rise time is 1.5 ns and the detector rise time is 2 ns, what is the cable rise time? A. 14 ns B. 6 ns C. 9 ns D. 12.5 ns
Last Answer : A. 14 ns
Description : Cross modulation on a receiver is eliminated at the A. RF stage B. mixer stage C. IF stage D. detector stage
Last Answer : D. detector stage
Description : What are the problems associated with switch type phase detector?
Last Answer : 1.The output voltage Ve is proportional to the input signal amplitude.This is undesirable because it makes phase detector gain and loop gain dependent on the input signal amplitude. 2.The output is proportional to cosQ making it non linear.
Description : What is a switch type phase detector?
Last Answer : An electronic switch is opened and closed by signal coming from VCO and the input signal is chopped at a repetition rate determined by the VCO frequency.This type of phase detector is called a ... detector since the phase information for only one half of the input signal is detected and averaged.
Description : Give the classification of phase detector:
Last Answer : 1.Analog phase detector . 2.Digital phase detector
Description : Consider a discrete memoryless channel and assume that H(x) is the amount of information per symbol at the input of the channel; H(y) is the amount of information per symbol at the output of the channel; H(x|y) is the amount of uncertainty ... (H(x) - H(x|y))] p(x) (D) max H(x|y) p(x)
Last Answer : (D) max H(x|y) p(x)
Description : Which of the following is the new name of CCITT? A. ITU-T B. ITU-R C. ITU-S D. ITU-D
Last Answer : A. ITU-T
Description : Which is not an ITU sector? A. ITU-W B. ITU-R C. ITU-T D. ITU-D
Last Answer : A. ITU-W
Description : Acquired immunity usually involves protein receptors on B and T cells that recognize discrete regions of the antigen called _____. a. haptens b. epitopes c. antibodies d. protein receptors
Last Answer : b. epitopes
Description : Refers to a continuous tone generated in a local exchange terminal through a combination of two frequencies 350 Hz, and 440 Hz. A. Busy tone B. Call waiting tone C. Dial tone D. Standard tone
Last Answer : B. Call waiting tone
Description : What is the mixing process? A. Distortion caused by auroral propagation B. The combination of two signals to produce sum and difference frequencies. C. The elimination of noise in wideband receiver by phase differentiation D. The elimination of noise in a wideband receiver by phase comparison
Last Answer : B. The combination of two signals to produce sum and difference frequencies.
Description : What is Combination Clipper?
Last Answer : When a portion of both positive and negative of each half cycle of the input voltage is to be clipped (or removed), combination clipper is employed.
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 : Which of the following is not a way of minimizing if not eliminating noise? A. Use redundancy B. Increase transmitted power C. Reduce signaling rate D. Increase channel bandwidth
Last Answer : D. Increase channel bandwidth
Description : Reference noise is ___________. A. a 1000 Hz, -90 dBm tone B. a noise that creates the same interfering effect as a 1000Hz, -90dBm tone C. a noise that creates zero dBrn in a voice channel D. B and C above
Last Answer : D. B and C above