Description : The ______ technique expands the bandwidthof a signal by replacing each data bit with n bits. A) FDM B) DSSS C) FHSS D) TDM
Last Answer : DSSS
Description : DMT is a modulation technique that combineselements of _______ and _______. A) FDM; TDM B) QDM; QAM C) FDM; QAM D) PSK; FSK
Last Answer : FDM; QAM
Description : _____ isan analog multiplexing technique to combine optical signals. A) FDM B) TDM C) WDM D) None of the above
Last Answer : WDM
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 : Which multiplexing technique shifts each signal to a different carrier frequency? A) FDM B) TDM C) Both (a)and (b) D) None of the above
Last Answer : FDM
Description : We candivide ____ into two different schemes: synchronousor statistical. A) FDM B) TDM C) WDM D) none of the above
Last Answer : TDM
Description : _____ isa digital multiplexing technique for combiningseveral low-ratechannels into onehigh-rate one. A) FDM B) TDM C) WDM D) None of the above
Description : _____ isa digitalprocess that allows several connections to share thehighbandwidth ofa link. A) FDM B) TDM C) WDM D) None of the above
Description : ____ is designed to use thehigh bandwidthcapabilityof fiber-optic cable. A) FDM B) TDM C) WDM D) None of the above
Description : Which multiplexing technique involves signals composed of light beams? A) FDM B) TDM C) WDM D) none of the above
Description : Which multiplexing technique transmits digital signals? A) FDM B) TDM C) WDM D) None of the above
Description : Which multiplexing technique transmits analog signals? A) FDM B) TDM C) WDM D) (a) and (c)
Last Answer : (a) and (c)
Description : In synchronous TDM, forn signal sources of the same data rate, eachframe contains _______ slots. A) n B) n + 1 C) n- 1 D) 0to n
Last Answer : n
Description : Which of the following is oldest multiplexing scheme? A. Frequency Division Multiplexing (FDM) B. Time Division Multiplexing (TDM) C. Code Division Multiplexing (CDM) D. Space Division Multiplexing (SDM)
Last Answer : D. Space Division Multiplexing (SDM)
Description : Multiplexing scheme use by baseband transmission. A. FDM B. Space multiplexing C. TDM D. Statistical multiplexing
Last Answer : C. TDM
Description : One of the reasons why FDM is being replaced by TDM is A. noise is amplified with voice when an FDM system is used B. it is difficult to place channels side by side C. there is more time than frequency D. Most available frequencies has been used
Last Answer : A. noise is amplified with voice when an FDM system is used
Description : Using_________each connected device is assigned a time slot whether or not the device has any thing to send. (A) WDM (B) FDM (C) TDM (D) STDM
Last Answer : (C) TDM
Description : Time synchronization is necessary in (A) FDM. (B) TDM. (C) WDM. (D) Quadrature multiplexing
Last Answer : (B) TDM.
Description : Compare FDM & TDM systems
Last Answer : Sr. No. FDM TDM 1 Divides the channel into the two or more frequency ranges that do not overlap. Divides and allocates certain Time periods to each channel. 2 Code word is ... Needs guard bands Needs guard time 4 Problem of crosstalk No problem of crosstalk
Description : In a fiber-optic cable, the signal is propagatedalong theinner core by _______. A) reflection B) refraction C) modulation D) none of the above
Last Answer : reflection
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 : A noise where foreign signal enters the path of the transmitted signal is called …… A. Impulse B. Inter modulation C. cross talk D. both b and c
Last Answer : C. cross talk
Description : A good example of a pilot tone system used in commercial frequency modulation stations. A. FDM B. Time division C. Stereo multiplexing D. Frequency modulation
Last Answer : C. Stereo multiplexing
Description : The simplest type of switching fabric is the ______ switch. A) crosspoint B) crossbar C) TSI D) STS
Last Answer : crossbar
Description : An STS multiplexer is a ______ device. A) one-layer B) two-layer C) three-layer D) four-layer
Last Answer : two-layer
Description : A ______is the end-to-end portion of the network between two STS multiplexers. A) section B) line C) path D) none of the above
Last Answer : path
Description : _______ allow insertion and extraction of signals. A) regenerators B) ADMs C) STS multiplexer/demultiplexers D) none of the above
Last Answer : regenerators
Description : A ________ is a repeater. A) regenerator B) ADM C) STS multiplexer/demultiplexer D) none of the above
Last Answer : STS multiplexer/demultiplexer
Description : An STS-3 frameis madeof ________columns. A) 9 B) 90 C) 270 D) none of the above
Last Answer : none of the above
Description : An STS-3 frameis madeof ______ rows. A) 1 B) 9 C) 27 D) none of the above
Last Answer : 27
Description : An STS-1 frameis made______columns A) 1 B) 9 C) 90 D) none of the above
Last Answer : 90
Description : An STS-1 frameis madeof ________rows A) 1 B) 9 C) 90 D) none of the above
Last Answer : 1
Description : A SONET system can use _________. A) STS multiplexers B) regenerators C) add/drop multiplexers D) all of theabove
Last Answer : add/drop multiplexers
Description : In SONET, OC-1 stands for: a. Optical Carrier level one b. Optical Coupler unidirectional c. Optical Channel one d. Optical Cable type 1
Last Answer : a. Optical Carrier level one
Description : In ________ TDM, slots are dynamically allocated to improvebandwidth efficiency. A) synchronous B) statistical C) isochronous D) none of the above
Last Answer : statistical
Description : In ________ TDM, each input connection hasan allotment in the outputeven if it is not sendingdata. A) synchronous B) statistical C) isochronous D) none of the above
Last Answer : synchronous
Description : In TDM, the transmissionrate of the multiplexed path isusually_______ thesum of thetransmission rates of thesignal sources. A) greater than B) less than C) equal to D) not related to
Last Answer : greater than
Description : SONET is a _______ TDM system. A) asynchronous B) synchronous C) statistical D) none of the above
Description : Four channels are multiplexed using TDM. If each channel sends 100 bytes/second and we multiplex 1 byte per channel, then the bit rate for the link is __________. a. 400 bps b. 800 bps c. 1600 bps d. 3200 bps
Last Answer : d. 3200 bps
Description : If link transmits 4000 frames per second and each slot has 8 bits, the transmission rate of circuit of this TDM is ______. a. 64 Kbps b. 32 Mbps c. 32 Kbps d. 64 MbpS
Last Answer : c. 32 Kbps
Description : The ______ layer is responsible for the movementof a signal from its optical source to its optical destination. A) section B) line C) path D) photonic
Last Answer : line
Description : The physical layer provides __________ a. mechanical specifications of electrical connectors and cables b. electrical specification of transmission line signal level c. specification for IR over optical fiber d. all of the mentioned
Last Answer : d. all of the mentioned
Description : The physical layer provides __________ A. mechanical specifications of electrical connectors and cables B. electrical specification of transmission line signal level C. specification for IR over optical fiber D. all of the mentioned
Last Answer : D. all of the mentioned
Description : What specifications does physical layer provides __________. A. mechanical specifications of electrical connectors and cables B. electrical specification of transmission line signal level C. specification for IR over optical fiber D. all of the mentioned
Description : The physical layer provides __________ a) mechanical specifications of electrical connectors and cables b) electrical specification of transmission line signal level c) specification for IR over optical fiber d) all of the mentioned
Last Answer : d) all of the mentioned
Description : Given the following statements: (a) Frequency Division Multiplexing is a technique that can be applied when the bandwidth of a link is greater than combined bandwidth of signals to be transmitted. (b) Wavelength Division Multiplexing (WDM) ... c) is true. (D) (a), (b) and (d) are true; (c) is false.
Last Answer : (D) (a), (b) and (d) are true; (c) is false.
Description : In SONET, STS stands for: a. Synchronous Transport Signal b. Synchronous Transport System c. Synchronous Transmission Signal d. Synchronous Transmission System
Last Answer : a. Synchronous Transport Signal
Description : What bit rate is possible when an OC-1 is carrying a DS-3 signal?
Last Answer : What is the answer ?
Description : n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In each batch about 120 ... dryer and the dryer efficiency is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.
Last Answer : Given that Qty of material dried per batch - 120 Kgs Moisture at inlet - 60% a. The quantity of moisture removed per batch. Water quantity in a wet batch - 120 x 0.6 = 72 Kgs. Quantity of bone dry ... - 48/0.95 = 50.5 Kgs. Equivalent water in a dry batch - 50.5 - 48 = 2.5 Kgs.
Description : A(n)_________ signal is a composite analogsignal with an infinite bandwidth. A) digital B) analog C) either (a)or (b) D) neither (a) nor (b
Last Answer : digital