Description : A 1 Mhz carrier is amplitude modulated by a pure 200-Hz audio test tone. Which of the following combinations of frequencies represent the total content of the AM signal? A. 1 MHz and 200 Hz B. 1 MHz and 1000.2 kHz C. 999.8 kHz, 1000 kHz, and 1000.2 kHz D. 999.8 kHz and 1000.2 kHz
Last Answer : C. 999.8 kHz, 1000 kHz, and 1000.2 kHz
Description : In_____ transmission, thephaseof the carrier signal is modulated to follow the changingvoltage level (amplitude) of the modulating signal. A) AM B) PM C) FM D) none of the above
Last Answer : PM
Description : In_____ transmission, the frequency of the carrier signal is modulated to follow the changing voltage level (amplitude)of the modulating signal. The peak amplitude and phase of the carrier signal remainconstant,but as ... of thecarrier changes correspondingly. A) AM B) PM C) FM D) none of the above
Last Answer : FM
Description : If the carrier of a 100 percent modulated AM wave is suppressed, the percentage power saving will be
Last Answer : 50
Description : A 400 W carrier is amplitude modulated to a depth of 75%.Calculate the total power in AM wave. (i) Explain the types of noise in a communication system. (ii) Compare simplex and duplex mode of communication.
Last Answer : (i) Noise: Noise is any spurious or undesired disturbances that mask the received signal in a communication system. a) Atmospheric Noise: Atmospheric Noise is also known as static noise which is the ... remote control ExamplesWalkytalky,telephone,mobile,Radar, FAX,Pager 4
Description : If the carrier of a 100 percent modulation modulated AM wave is suppressed, the percentage power saving will be (A) 50.55 (B) 15.55 (C) 10.66 (D) 66.66
Last Answer : If the carrier of a 100 percent modulation modulated AM wave is suppressed, the percentage power saving will be 66.66
Description : A 1000W carrier is amplitude modulated to a depth of 85%. Calculate the total power of the modulated wave? A. 1361.25 W B. 680.62 W C. 1425 W D. 712.5 W
Last Answer : A. 1361.25 W
Description : What is meant by the term modulation index? A. The processor index. B. The ratio between the deviation of a frequency modulated signal and the modulating frequency. C. The FM signal-to-noise ratio. D. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.
Last Answer : B. The ratio between the deviation of a frequency modulated signal and the modulating frequency.
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 : 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 : 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 in which the modulated wave is always present. A. Carrier modulation B. Front-end C. Continuous modulation D. Log-periodic modulation
Last Answer : C. Continuous modulation
Description : If frequency of modulated wave is less than frequency of carrier wave, then input signal is A. negative B. positive C. zero D. infinite
Last Answer : negative
Description : The _______ technique uses M different carrier frequencies that are modulated by the source signal. At one moment, the sign modulates one carrier frequency; at the next moment, thesignal modulates another carrier frequency. A) FDM B) DSSS C) FHSS D) TDM
Last Answer : FHSS
Description : Carrier is A. One or more conductors that serve as a common connection for a related group of devices B. a continuous frequency capableof being modulated or impressed witha second signal C. ... that provides a data communications service among stations attached tothe network E. None of the above
Last Answer : a continuous frequency capableof being modulated or impressed witha second signa
Description : Geodimeter is based on: (A) Propagation of modulated light waves (B) Propagation of infrared radiation (C) The visible light as carrier with frequency of the order of 5 × 1014 Hz (D) High frequency radio waves
Last Answer : Answer: Option A
Description : The modulated picture carrier wave includes the composite video signal as the:
Last Answer : Symmetric envelope of amplitude variations
Description : A system where the modulated RF picture and sound carrier signals are distributed in a cable network, instead of wireless system.
Last Answer : CATV
Description : The bandwidth required for a modulated carrier depends on:
Last Answer : the baseband frequency range
Description : A 4 GHz carrier is amplitude modulated by a low-pass signal of maximum cut off frequency 1 MHz. lf this signal is to be ideally sampled, the minimum sampling frequency should be nearly
Last Answer : A 4 GHz carrier is amplitude modulated by a low-pass signal of maximum cut off frequency 1 MHz. lf this signal is to be ideally sampled, the minimum sampling frequency should be nearly 4 Ghz
Description : How is a beam of electrons velocity-modulated?
Last Answer : By alternately speeding up or slowing down the electrons
Description : Why can phase-modulated signals be detected by fm detectors?
Last Answer : Because of the incidental frequency shift that is caused while phase-shifting a carrier wave that is similar to fm modulation.
Description : Where is the intelligence contained in a phase-modulated signal?
Last Answer : In the amount and rate of phase shift of the carrier wave.
Description : Which edges of the pulse can be modulated in pulse duration modulation?
Last Answer : Either, or both at the same time.
Description : When using frequencies above 30 megahertz, you are normally limited to using what range?
Last Answer : Line of sight.
Last Answer : The frequency modulated (FM) radio frequency range is nearly 90 - 105 MHz.
Description : What is the temperature range within which a disk will operate?
Last Answer : 10 to 50 degrees Celsius or 50 to 120 degrees Fahrenheit.
Description : hard disks should be stored in an environment that stays within what relative humidity and temperature range?
Last Answer : electronics onto the disk. 30-60 percent relative humidity. b. 70-80 degrees Fahrenheit.
Description : Type of emission produced by one of the early radio transmitter in trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier. A. Digital emission B. Key emission C. Cycle emission D. Spark emission
Last Answer : D. Spark emission
Description : The ideal radar spectrum has what relationship to the carrier frequency?
Last Answer : Symmetrical above and below the carrier frequency.
Description : Why do 2D air-search radars use relatively low carrier frequencies and low pulse-repetition rates?
Last Answer : Increased maximum range.
Description : What type of modulation depends on the carrier-wave phase shift?
Last Answer : Phase.
Description : How does the reactance-tube modulator impress intelligence onto an rf carrier?
Last Answer : By changing the reactance of an oscillator circuit in consonance with the modulating voltage.
Description : What characteristic of a carrier wave is varied in frequency modulation?
Last Answer : Instantaneous frequency.
Description : Why are manual transmissions in cars making a big comeback?
Last Answer : They get better gas mileage.
Description : Are Mazda & Mitsubishi transmissions interchangeable?
Last Answer : Need Answer
Description : Is it against FCC regulations to speak Spanish over 2-way radio transmissions?
Last Answer : No, of course not.
Description : Are the transmissions in a 1990 Caprice stable?
Last Answer : The Caprice has never had any major history of transmission trouble. One can deduct then that the transmissions are stable.
Description : What are the different types of auto transmissions?
Last Answer : There are basically three types of transmissions: manual, automatic and continuously variable transmissions (CVT). CVT is the only other type that would fall under the automatic category. transmissions for a ++++++ transmissions for a Dodge truck
Description : How expensive are transmissions?
Last Answer : If you have been having trouble with your auto transmission, I would suggest going to a local auto company near you. Auto transmissions are a little more expensive than manual transmissions.
Description : Where can I find used transmissions for sale?
Last Answer : There are many different websites that offer used transmissions for sale. In order to find them in your area check Craigslist, the local paper or your neighborhood mechanic.
Description : How much do rebuilt transmissions cost?
Last Answer : If you do it yourself with the parts it will cost around $1800. If you hire a mechanic to do it could cost $2500 or more because of the labor costs.
Description : What is the delay time for satellite transmissions from earth transmitter to earth receiver? A. 0.5 s B. 1s C. 5 ms D. 0.25 s
Last Answer : A. 0.5 s
Description : In cellular system, _____ defines the geographic distance that is required between cells using identical frequencies in order to avoid interference between the radio transmissions at these cells. A. frequency-reuse ratio B. distance-to-reuse ratio (D/R) C. reuse format plan ratio D. reuse factor
Last Answer : B. distance-to-reuse ratio (D/R)
Description : When an insured foreign parcel is redirected form one country to the another . a) No additional insurance fee is to be levied b) Half of the original insurance fee is to levied for such transmissions c) A fresh insurance fee become payable for each such transmission d) None of the above
Last Answer : c) A fresh insurance fee become payable for each such transmission
Description : A communications device that combines transmissions from several I/O devices into one line is a a. concentrator b. modifier c. multiplexer d. full-duplex line
Last Answer : multiplexer
Description : In ATM, the _______layeraccepts transmissions from upper-layer servicesand maps them into ATM cells. A) physical B) ATM C) AAL D) none of the above
Last Answer : AAL
Description : Which of the following is not a disadvantage of wireless LAN? A. Slower data transmission B. higher error rate C. interference of transmissions from different computers D. All of theabove
Last Answer : All of theabove
Description : A communication device that combines transmissions from several I/O devices into one line is a A) Concentrator B) Modifier C) Multiplexer D) Full duplex file
Last Answer : C) Multiplexer
Description : Consider a link with packet loss probability of 0.2. What is the expected number of transmissions it would take to transfer 200 packets given that the stop and wait protocol is used? a. 125 b. 250 c. 225
Last Answer : b. 250