Description : Which cavity of a three-cavity klystron causes most of the velocity modulation?
Last Answer : The middle cavity.
Description : What can be added to the basic two-cavity klystron to increase the amount of velocity modulation and the power output?
Last Answer : Intermediate cavities between the input and output cavities.
Description : What types of modulation are shipboard receive-only equipment designed to receive?
Last Answer : Fm or psk.
Description : What type of modulation do most analog fiber optic communications systems use?
Last Answer : Intensity modulation.
Description : Define modulation.
Last Answer : The process of varying one or more characteristics of an optical signal to encode and convey information.
Description : Which junction of the transistor in the common-emitter detector detects the modulation envelope?
Last Answer : Emitter-base junction
Description : Phase-shift keying is similar to what other two types of modulation?
Last Answer : Cw and frequency-shift keying.
Description : What type of modulation depends on the carrier-wave phase shift?
Last Answer : Phase.
Description : How is the degree of modulation expressed in an fm system?
Last Answer : As the ratio of the frequency deviation to the maximum frequency deviation allowable.
Description : What characteristic of a carrier wave is varied in frequency modulation?
Last Answer : Instantaneous frequency.
Description : Name the modulation system in which the frequency alternates between two discrete values in response to the opening and closing of a key?
Last Answer : . Frequency-shift keying.
Description : What are the two types of angle modulation?
Last Answer : Frequency and phase.
Description : What is the primary advantage of pulse-modulation systems?
Last Answer : . Low susceptibility to noise.
Description : Pulse-code modulation requires the use of approximations of value that are obtained by what process?
Last Answer : Quantization.
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 : What is the main disadvantage of pulse-position modulation?
Last Answer : It requires synchronization between the transmitter and receiver.
Description : Which edges of the pulse can be modulated in pulse duration modulation?
Last Answer : Either, or both at the same time.
Description : What characteristics of a pulse can be changed in pulse time modulation?
Last Answer : The time duration of the pulses or the time of occurrence of the pulses.
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 : To ensure the accuracy of a transmission, what is the minimum number of times a modulating wave should be sampled in pulse modulation?
Last Answer : 2.5 times the highest modulating frequency.
Description : What action is necessary to impress intelligence on the pulse train in pulse modulation?
Last Answer : Some characteristic of the pulses has to be varied.
Description : With a single modulating tone, what is the amplitude of the sideband frequencies at 100-percent modulation?
Last Answer : One-half the amplitude of the carrier.
Description : What is percent of modulation?
Last Answer : The depth or degree of modulation.
Description : How much must the fpa plate current vary to produce 100- percent modulation in a plate modulator?
Last Answer : Between 0 and nearly two times its unmodulated value.
Description : What is modulation?
Last Answer : Modulation is the impressing of intelligence on a transmission medium.
Description : What is amplitude modulation?
Last Answer : Any method of modulating an electromagnetic carrier frequency by varying its amplitude in accordance with the intelligence.
Description : The ratio of the level of the modulated output of a transmitter under conditions of standard test modulation to the level of the demodulated output with no modulation applied both measured with the ... . Reference audio output B. None of these C. Audio frequency response D. Residual noise level
Last Answer : D. Residual noise level
Description : If digitaldata rateof 9600 bps is encoded using 8-level phaseshift keying (PSK) method, the modulation rate is A. 1200 bands B. 3200 bands C. 4800 bands D. 9600 bands E. None of the above
Last Answer : 3200 bands
Description : Which of the following is the world’s first cellular system to specify digital modulation and network level architecture? a) GSM b) AMPS c) CDMA d) IS-54
Last Answer : a) GSM
Description : The amplifiers following the modulated stage in a low level modulation AM system be (A) linear amplifier (B) harmonic generators (C) class C power amplifiers (D) class untuned amplifiers
Last Answer : The amplifiers following the modulated stage in a low level modulation AM system be class C power amplifiers
Description : A NAND gate has inputs labeled as A, B, and C. If A and B are HIGH, C must be at what logic level to produce a HIGH output?
Last Answer : . Low.
Description : A NAND gate has Z and X as inputs. What will be the output logic level if Z is HIGH and X is LOW?
Last Answer : HIGH.
Description : In Manchester encoding, does a low-to-high light level transition occurring in the middle of the bit duration represent a binary 1 or a binary 0?
Last Answer : Binary 0.
Description : In NRZ code, does the presence of a high-light level in the bit duration represent a binary 1 or a binary 0?
Last Answer : Binary 1.
Description : What type of modulator is the cathode modulator (low- or high-level)?
Last Answer : Low-level.
Description : What is a Modem? What is the need of MODEM in data communication? Explain at least one modulation technique used for high speed modems.
Last Answer : Modems are essentially used to interface digital circuits to transmit information on analogue channels like telephone systems. Modem (from modulator-demodulator) is a device that modulates an analogue carrier ... caused by the lines makes the detection even harder than amplitude modulation.