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 : 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 : ECE Board Exam March 1996 The modulation system used for telegraphy is A. frequency-shift keying B. two-tone modulation C. pulse-code modulation D. single-tone modulation
Last Answer : A. frequency-shift keying
Description : Which of the following sensor work based on radio detection and ranging? A : Sonar B : Radar C : Intertial D : Biosensor
Last Answer : B : Radar
Description : ECE Board Exam March 1996 One type of pulse communications system uses pulse that appear as a group, and which vary in number according to the loudness of the voice. This type of ... A. pulse duration modulation B. pulse amplitude modulation C. pulse code modulation D. pulse position modulation
Last Answer : A. pulse duration modulation
Description : ECE Board Exam March 1996 Which of the following pulse modulation systems is analog? A. Delta B. Differential PCM C. PWM D. PCM
Last Answer : C. PWM
Description : In modulation technique, which of the following is referred to audible pitch? A. Width B. Frequency C. Harmonic D. Amplitude
Last Answer : B. Frequency
Description : This is referred to a product of simultaneous frequency and amplitude modulation or a carrier frequency variation which produces unwanted distortion. A. Absorption modulation B. Simultaneous modulation C. Dynamic instability D. Series modulation
Last Answer : C. Dynamic instability
Description : Used for time division multiplexing. A. Frequency modulation B. Pulsed modulation C. SSB D. Amplitude modulation
Last Answer : B. Pulsed modulation
Description : The modulation technique used by GSM cellular system A. Phase shift keying B. Frequency shift keying C. Gaussian minimum shift keying D. QAM
Last Answer : C. Gaussian minimum shift keying
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 : 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 : 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 difference between phase and frequency modulation? A. Is purely theoretical because they are the same in practice B. Lies in poorer audio response of phase modulation C. Lies in the different definitions of the modulation index D. Is too great to make two systems compatible
Last Answer : C. Lies in the different definitions of the modulation index
Description : What, if any, noise susceptibility advantage exists for pulse-amplitude modulation over analog amplitude modulation?
Last Answer : Both are susceptible to noise and interference
Description : A pulse modulation technique as the width of a constant amplitude pulse is varied proportional to the amplitude of the analog signal at the time the signal is sampled.
Last Answer : PWM, PLM, PDM
Description : Pulse – amplitude modulation signals are multiplexed by using
Last Answer : FET switches
Description : Type of modulation used in TV broadcast visual transmitter. A. Pulse modulation B. DSBFC C. Vestigial sideband D. SSBFC
Last Answer : C. Vestigial sideband
Description : Modulation in which no signal is present between pulses A. Pulse modulation B. QAM C. PSK D. FSK
Last Answer : A. Pulse modulation
Description : In amplitude modulation technique the unmodulated carrier is referred to as having ______. A. 100% modulation B. 0% modulation C. 50% modulated D. Over modulated
Last Answer : B. 0% modulation
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 : If the percentage modulation of an AM amplifier is 88% and the modulating signal is 1 volt, the carrier has an amplitude of _______________. A. 1.14 volts B. 0.88 volt C. 1.88 volts D. 0.12 volt
Last Answer : A. 1.14 volts
Description : Three audio waves with 100,200 and 300 volts amplitude respectively, simultaneously modulate a 450 volts carrier. What is the total percent of modulation of the AM wave? A. 69 % B. 115.5 % C. 50% D. 83%
Last Answer : D. 83%
Description : What distortion is not caused by transmission line characteristics? A. Phase distortion B. Pulse shape distortion C. Spacing bias distortion D. Amplitude distortion
Last Answer : C. Spacing bias distortion
Description : Describe amplitude shift keying (ASK) modulation with suitable circuit diagram.
Last Answer : Explanation:- ASK MODULATOR: The process where a binary information signal directly modulates the amplitude of an analog carrier. The digital signal is used to switch the carrier between amplitude levels is ... Block diagram of ASK Transmitter / ASK modulator:- Waveforms:-
Description : What is the full form of 'AM' regarding radio broadcasting? (1) Amplitude Movement (2) Anywhere Movement (3) Amplitude Matching (4) Amplitude Modulation
Last Answer : (4) Amplitude Modulation Explanation: AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still ... frequency. It then amplifies changes in the signal voltage to drive a loudspeaker or earphones.
Description : What is the full form of ‘AM’ regarding radio broadcasting? (1) Amplitude Movement (2) Anywhere Movement (3) Amplitude Matching (4) Amplitude Modulation
Last Answer : Amplitude Modulation
Description : Which of the following is not a common microwave application? A. Radar B. Data transmission C. Space communications D. Mobile radio
Last Answer : D. Mobile radio
Description : In radio regulation, the first symbol in the designation of radio emission is ______. A. Bandwidth B. Nature of signal(s) modulation the main carrier C. Type of modulation of the main carrier D. Type of information to be transmitted
Last Answer : C. Type of modulation of the main carrier
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 : What is the primary advantage of pulse-modulation systems?
Last Answer : . Low susceptibility to noise.
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 : 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 : What is the reason why companding is employed in PCM systems? A. To overcome impulse noise in PCM receivers B. To allow amplitude limiting in the receivers C. To solve quantizing noise problem D. To protect small signals in PCM from quantizing distortion
Last Answer : D. To protect small signals in PCM from quantizing distortion
Description : A pulse radar has a pulse repetition frequency (PRF) of 3 KHz. If the radar is emitting at 10 GHz, what is the maximum unambiguous range for this radar? A) 5 Km B) 5 m C) 50 Km D) 15 m
Last Answer : A pulse radar has a pulse repetition frequency (PRF) of 3 KHz. If the radar is emitting at 10 GHz, what is the maximum unambiguous range for this radar? A) 5 Km B) 5 m C) 50 Km D) 15 m
Description : A pulse compression radar transmits an encoded pulse having a frequency chirp from 990 MHz to 1010 MHz centred around 1 GHz. The range resolution capability of this radar is A) 7.5 m B) 7.5 Km C) 75 m D) 750 m
Last Answer : A pulse compression radar transmits an encoded pulse having a frequency chirp from 990 MHz to 1010 MHz centred around 1 GHz. The range resolution capability of this radar is 7.5 m
Description : What is pulse-frequency modulation?
Last Answer : A method of pulse modulation in which a modulating wave is used to frequency modulate a pulse-generating circuit
Description : In frequency modulation, amplitude of modulated wave is A. positive B. negative C. constant D. zero
Last Answer : constant
Description : Variation in amplitude or frequency of carrier wave is called A. amplitude modulation B. frequency modulation C. modulation D. bandwidth
Last Answer : modulation
Description : Bits can be sent over guided and unguided media as analog signal by ___________ a. digital modulation b. amplitude modulation c. frequency modulation d. phase modulation
Last Answer : a. digital modulation
Description : What determines the ability of radar to determine the bearing to a target? A. Speed of light B. Speed of target C. Antenna directivity D. Frequency of signal
Last Answer : C. Antenna directivity
Description : What is the most commonly used intermediate frequency of radar receivers? A. 40 MHz B. 60 MHz C. 70 MHz D. 30 MHz
Last Answer : D. 30 MHz
Description : Which of the following antennas is used for testing and adjusting a transmitter for proper modulation, amplifier operation and frequency accuracy? A. Elementary B. Real C. Isotropic D. Dummy
Last Answer : D. Dummy
Description : Why are frequency modulation transmitters more efficient? A. Because their power is increased by class C amplifiers B. Because their power is increased by class A amplifiers C. Because their power is increased by class B amplifiers D. Because their power is increased by class AB amplifiers
Last Answer : A. Because their power is increased by class C amplifiers
Description : What is the deviation ratio for an FM-phone signal having a maximum frequency swing of plus or minus 5 kHz and accepting a maximum modulation rate of 3kHz? A. 60 B. 0.16 C. 0.6 D. 1.66
Last Answer : D. 1.66