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 : When no signal is being received, the loudspeaker is not entirely silent as a result of the presence of A. parasitic oscillations in some of the receiver stages. B. negative feedback in each stage. C. spurious frequencies as a result of improper neutralization. D. internal receiver noise.
Last Answer : D. internal receiver noise.
Description : A modulation which does not follow the sine wave pattern, it produces undesirable harmonics such as spurious emission A. 0% modulated B. Over-modulated C. Unmodulated D. 100% modulated
Last Answer : B. Over-modulated
Description : Emission on a frequency or frequencies immediately outside the necessary bandwidth which result from the modulation process except spurious emission. A. Radiation B. Noise C. Out of the band D. Interference
Last Answer : C. Out of the band
Description : Indicate the false statement. A. HF mixer are generally noisier than HF amplifiers. B. Impulse noise voltage is dependent on bandwidth C. Thermal noise is independent of the frequency at which is measured. D. Industrial noise is usually of the impulse type.
Last Answer : B. Impulse noise voltage is dependent on bandwidth
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 : 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 : Which circuit contributes most of the noise in a receiver? A. IF amplifier B. Demodulator C. AF amplifier D. Mixer
Last Answer : D. Mixer
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 : Which of the following is the basic synthesizer circuit? A. Frequency divider B. Frequency multiplier C. PLL D. Mixer
Last Answer : C. PLL
Description : In a triple conversion superheterodyne receiver, diode mixer stages are operated A. In the linear region B. In the nonlinear region C. As class A amplifiers D. As class B amplifiers
Last Answer : B. In the nonlinear region
Description : What establishes the receiver bandwidth? A. RF amplifier B. Mixer C. Local oscillator D. IF amplifier
Last Answer : D. IF amplifier
Description : What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna
Last Answer : C. Local oscillator, mixer and RF amplifier
Description : Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer. A. Antenna feed B. AGC C. RF amplifier D. Local oscillator
Last Answer : D. Local oscillator
Description : Referred to as the stage in the radio receiver that contributes most of the noise. A. IF amplifier B. Supply stage C. Speaker D. Mixer
Description : After the IF stages have been aligned, the next stage to align in FM receiver is. A. local oscillator B. limiter stage C. RF amplifier D. mixer stage
Last Answer : A. local oscillator
Description : In an FM receiver, which circuit removes amplitude variations? A. Exciter B. Mixer C. Discriminator D. Limiter
Last Answer : D. Limiter
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 : Modulation means A. Varying of information B. Utilization of a single transmission channel to carry multiple signals C. Varying of some parameters of a carrier such as its amplitude to transmit information D. Transmit pulses in DC form on a copper wire
Last Answer : C. Varying of some parameters of a carrier such as its amplitude to transmit information
Description : What type of balun (balanced-to-unbalanced) is used in high frequency applications? A. Transformer type balun B. A specially configured coaxial transmission line C. A specially configured parallel-wire line D. A λ/2 transformer balun
Last Answer : B. A specially configured coaxial transmission line
Description : Refers to the first symbol in an emission designation with an amplitude modulated main carrier represented by letter H. A. Single sideband suppressed carrier B. Double sideband full carrier C. Independent sideband D. Double sideband
Last Answer : B. Double sideband full carrier
Description : A form of single sideband emission where the degree of carrier suppression enable the carrier to be reconstituted and be used for demodulation. A. Half carrier single sideband emission B. Full carrier single sideband emission C. Reduced carrier single sideband emission D. Double sideband emission
Last Answer : C. Reduced carrier single sideband emission
Description : A satellite stay in orbit because the following two factors are balanced A. Satellite weight and speed B. Gravitational force and centrifugal force C. Centripetal force and speed D. Satellite weight and the pull of the moon and sun
Last Answer : B. Gravitational force and centrifugal force
Description : A transmission line consisting of two conductors that have equal resistance per unit length. A. Unbalanced line B. Open-wire line C. Balanced line D. Coaxial line
Last Answer : C. Balanced line
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 : Transmission lines are either balanced or unbalanced with respect to _________. A. negative terminal B. input C. ground D. positive terminal
Last Answer : C. ground
Description : When a transmission line uses ground return, it is called a/an __________ line. A. ungrounded B. balanced C. unbalanced D. grounded
Last Answer : C. unbalanced
Description : In the phase shift method, How many circuits must be balanced? A. None of these B. 1 C. 4 D. 2
Last Answer : D. 2
Description : ECE Board Exam March 1996 The standard that specifies a balanced interface cable that will operate bit rates up to 10 Mbps with in a span distances up to 1200 m. A. RS-423A B. RS-422A C. RS-550A D. RS-449A
Last Answer : B. RS-422A
Description : What type of modulation is used on voice and video signals? A. AM B. FM C. SSB D. QPSK
Last Answer : B. FM
Description : In radio signal emission designation, the fifth symbol means A. Details of signals B. Type of information transmitted C. Nature of multiplexing D. Nature of signal modulating the main carrier
Last Answer : C. Nature of multiplexing
Description : The third symbol in the designation of radio emission under the ITU rules refers to A. Type of the modulation of the main carrier B. Bandwidth C. Nature of the signals modulating the main carrier D. Type of information to be transmitted
Last Answer : D. Type of information to be transmitted
Description : The first symbol in the designation of radio emission under the ITU rules to A. Nature of signals modulating the main carrier B. Type of information to be transmitted C. Bandwidth D. Type of modulation of the main carrier
Last Answer : D. Type of modulation of the main carrier
Description : Spurious coins detected at the counter are sent to _____ A. RBI B. GOI C. IBRD D. Mint E. None of the Above
Last Answer : D. Mint Explanation: when Spurious coins tendered over the counter, it should be cut and handed over to the tenderer. If the tenderer disputes it, the coins should be sent to the mint at his cost, for examination.
Description : Spurious tuples may occur due to i. Bad normalization ii. Theta joins iii. Updating tables from join a) i& ii b) ii & iii c) i& iii d) ii & iii
Last Answer : a) i& ii b) ii & iii
Description : Most often, the teacher - student communication is: (A) Spurious (B) Critical (C) Utilitarian (D) Confrontational
Last Answer : (C) Utilitarian
Description : The sequential operations in scientific research are (A) Co-variation, Elimination of Spurious Relations, Generalisation, Theorisation (B) Generalisation, Co-variation, Theorisation, ... Relations, Covariation (D) Elimination of Spurious Relations, Theorisation, Generalisation, Covariation.
Last Answer : (A) Co-variation, Elimination of Spurious Relations, Generalisation, Theorisation
Description : One of the aims of the scientific method in research is to: (A) improve data interpretation (B) eliminate spurious relations (C) confirm triangulation (D) introduce new variables
Last Answer : Answer: B aims of the scientific method in research is: Observe and Describe Predict Determination of the Causes Explain The aims of research can then be finetuned, or may serve to open up new areas of interest. Either way, the store of human knowledge has been enriched and increased.
Description : Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity
Last Answer : A. increases sensitivity to weak signals
Description : Which of the following antennas receive signals in the horizontal plane equality well from all directions? A. Horizontal Hertz antenna B. Vertical loop antenna C. Vertical Yagi antenna D. A vertical antenna which is a quarter-wavelength long
Last Answer : D. A vertical antenna which is a quarter-wavelength long
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 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 : Collects very weak signals from a broadcast satellite A. Helical antenna B. Satellite dish C. LNA D. TWT
Last Answer : B. Satellite dish
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 : 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 : Which of the following antennas receives signals equally well from all directions in a horizontal plane? A. Hetz antenna B. Vertical Marconi antenna C. Yagi antenna D. Helical antenna
Last Answer : B. Vertical Marconi antenna
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 : ____ system transmits frequency-division-multiplexed voice band signals over a coaxial cable for distances up to 4000 miles. A. T carrier B. X carrier C. L carrier D. F carrier
Last Answer : C. L carrier
Description : How many voice signals (4 kHz max.) would fit into a 5 MHz spectrum? A. 1250 B. 500 C. 1000 D. 1500
Last Answer : A. 1250
Description : In data communication the transmission of binary signals will require _______. A. Same bandwidth as analog B. More bandwidth than analog C. Less bandwidth than analog D. Bigger cable diameter
Last Answer : B. More bandwidth than analog