Give any four advantages of voice frequency signaling over DC signaling system.

Give any four advantages of voice frequency signaling over DC signaling system. 
by

1 Answer

Answer :

Advantages of Voice Frequency Signaling Over DC Signaling System: 1. Large number of circuits can be easily derived over a single pair of wires (single pair can control 18 stations). 2. Signal attenuation can be compensated by use of repeater stations. 3. No interference and cross talk over adjacent conductors. 4. Can be used over long distances. 5. Can be used where large number of equipment can be controlled. 

by

Related questions

Give any four advantages of remote control system.

Description : Give any four advantages of remote control system.

Last Answer : Advantages of remote control system: 1. As substations and control posts are unattended (due to remote controls) there is considerable savings due to less manpower. 2. Central control station ... Switching operations are carried out safely, quickly, and economically. 6. Maintenance cost is low.

Sources of impulse noise induced in communication channels. A. Erroneous digital coding bit caused by an error on a transmission facility B. Transients due to relay operation C. Crosstalk from dc signaling systems D. All of these

Description : Sources of impulse noise induced in communication channels. A. Erroneous digital coding bit caused by an error on a transmission facility B. Transients due to relay operation C. Crosstalk from dc signaling systems D. All of these

Last Answer : D. All of these

List any four current collectors for overhead system. State application of each.

Description : List any four current collectors for overhead system. State application of each.

Last Answer : Current Collectors for Overhead System With Their Application: 1. Trolley (Pole) collector: It is used for trolley buses having speed range from 20kmph to 32kmph. 2. Cable collector: This ... used for main line service locomotives, urban trains, suburban trains etc. having higher speed range.

List any four weaknesses of LIM propelled railway traction system.

Description : List any four weaknesses of LIM propelled railway traction system.

Last Answer : Weaknesses of LIM Propelled Railway Traction System: 1. The system requires looping of all reaction rails all along the route. This considerably adds to the cost of track. 2. Since Al is relative ... in the magnetic and electric circuits at entry and exit ends of motor, poor motor efficiency.

State any four ideal requirements of signaling system.

Description : State any four ideal requirements of signaling system.

Last Answer : i) Unless the whole section of track governed by the signal is clear & safe, it should not be possible to display safe' indication. ii) Failure of any component of signaling scheme should give danger ... shall be provided in the same track space for at least 600m in the rear of the signal.

State four important features of LEM that differ it from normal electric motor.

Description : State four important features of LEM that differ it from normal electric motor. 

Last Answer : Important Features of LEM That Differ it From Normal Electric Motor: 1. In LEM, primary & secondary or stator & rotor have longitudinal arrangement while normal electric motor has circular ... in high speed levitated system while normal electric motor is used for rotary mechanical output.

State any four relays used for catenary protection. State function of each relay.

Description : State any four relays used for catenary protection. State function of each relay.

Last Answer : Relays Used for Catenary Protection: 1. MHO relay: Wrong coupling protection. 2. MHO relay: Over current protection at farthest point. 3. Over current relay: Over current protection against faults near substation 4. Under voltage relay: Protection against faults far away from substation. 

Give protection scheme used for 25kV catenary protection for AC traction.

Description : Give protection scheme used for 25kV catenary protection for AC traction.

Last Answer : Protection Scheme Used for 25kV Catenary Protection for AC Traction: As shown in the figure below the scheme consists of 1) MHO relay that makes use of the impedance phase angle to get proper ... adjustment. 2) Over current relay. 3) Under voltage relay for low voltage protection.

Give the purpose and location of neutral section and section insulator.

Description : Give the purpose and location of neutral section and section insulator. 

Last Answer : Purpose of Neutral section: Passing of pantograph under insulated overlap will cause short circuit between two phases, damaging OHE & pantograph. To avoid this bridging, a neutral section is inserted between them ... Location: Located at cross over from one track to other, from main line to siding.

Write any four advantages of VF signalling over DC signalling.

Description : Write any four advantages of VF signalling over DC signalling.

Last Answer : Ans: Advantages of VF signaling over DC signaling: 1) Large number of circuits can be easily derived over a single pair of wires (single pair can control 18 stations). 2) Signal attenuation can be ... Can be used over long distances. 5) Can be used where large number of equipment can be controlled

Explain with neat diagram trolley collector for overhead system

Description : Explain with neat diagram trolley collector for overhead system

Last Answer : Trolley Collector for Overhead System:  This consists of a grooved gun metal wheel or grooved slider shoe with carbon insert carried attached to the end of a long pole provided on the top of ... gives rise to high current density. Suitable for comparative low speed (say 22 to 30 kmph).

____________ is the out-of-band signaling between toll central offices (Bell System Standard) A. 2,000 Hz B. 800 Hz C. 3,835 Hz D. 3700 Hz

Description : ____________ is the out-of-band signaling between toll central offices (Bell System Standard) A. 2,000 Hz B. 800 Hz C. 3,835 Hz D. 3700 Hz

Last Answer : D. 3700 Hz

Explain with neat sketch overload protection for power circuit of locomotive.

Description : Explain with neat sketch overload protection for power circuit of locomotive.

Last Answer : Overload Protection for Power Circuit of Locomotive:  1. To protect the main power circuit from overload, the thermal overload relays are used. 2. The overload is sensed by the ... overload relay OLR3 operates for overload fault on traction motor due to the flashover of traction motors. 

Explain protection of locomotive from overvoltage and under voltage

Description : Explain protection of locomotive from overvoltage and under voltage

Last Answer : Protection of Locomotive From Overvoltage and Under Voltage: 1. For protection against over voltages the over voltage relay which is basically a potential transformer (PT) is used. 2. ... a relay triggering an alarm, which enables the power controller to react and take corrective measures.

Explain the surge protection of electric locomotive from i) Direct lightening stroke ii) Switching surges

Description : Explain the surge protection of electric locomotive from i) Direct lightening stroke ii) Switching surges

Last Answer : i)Protection of Electric Locomotive From Direct Lightening Stroke:  1. The direct lightning strokes may strike on the overhead conductor on the roof of the locomotive. 2. To protect the ... reduce the steepness of the wave front and also help to absorb the energy in the resistance.

Explain with neat diagram i) Sectioning and paralleling post ii) Sub sectioning post

Description : Explain with neat diagram i) Sectioning and paralleling post ii) Sub sectioning post

Last Answer : i) Sectioning and Paralleling Post: Explanation of Sectioning and Paralleling Post: 1. The power supply arrangement is as shown in above figure for two track lines between feeding posts and ... subsection or the other. 4. There is no interrupter for paralleling the up and down track line

List different types of signals. State application of each.

Description : List different types of signals. State application of each.

Last Answer : Different Types of Signals: 1) Flag signals: This is shown by signalman if green flag is raised; it means to proceed with caution. Green flag shown down, it means there is track defect; ... green lamps indicate indications as in the 2-aspect system, and the yellow lamp shows the caution indication.

Write down the circuit breaker with their rating used in traction substation. Explain any one.

Description : Write down the circuit breaker with their rating used in traction substation. Explain any one.

Last Answer : Circuit Breaker With Their Rating Used in Traction Substation: Rated capacity of a circuit breaker is 750Amps at 25 kV, 500MVA. Its overall tripping time is 0.14 seconds composed of 0.04 ... but in case of traction substation application, mostly Minimum Oil Circuit Breaker (MOCB) is preferred.

Draw and explain in brief construction of Diamond Pantograph. Write one advantage and one disadvantage of it.

Description : Draw and explain in brief construction of Diamond Pantograph. Write one advantage and one disadvantage of it.

Last Answer : Diamond Pantograph: Construction of Diamond Pantograph: 1)Diamond Pantograph consist of pressed steel channel sectional fitted with renewable collector strips and supported at the apex of Pentagonal ... It requires more maintenance than Faiveley type. 4. It is costlier than Faiveley type.

With neat sketch explain automatic weight tension and temperature compensation.

Description : With neat sketch explain automatic weight tension and temperature compensation.

Last Answer : Automatic Weight Tension and Temperature Compensation: The tension in overhead lines in traction systems depends on the temperature. Higher temperatures lead to expansion of conductors and hence sag. It is therefore ... figure. The tension in the contact wire and catenary is around 1000 kg.

Explain the following - 1) Encumbrance 2) Span length.

Description : Explain the following - 1) Encumbrance 2) Span length.

Last Answer : Encumbrance: It is the axial distance between catenary and contact wire. Its value is maintained at 1.4 m as per rules except at i) Turn outs, ii) Overlaps iii) In the vicinity of over ... depends various factors like: i) Wind pressure ii) Curvatures iii) Current collection point of view etc.

State the classification of locomotive.

Description : State the classification of locomotive.

Last Answer : Classification of Locomotive:  A) Based on the types of service rendered:  1. Freight service for transportation of goods only.  2. Passenger service for transportation of passengers.  3. Mixed traffic ... the type of supply used:  1. Alternating current (AC)  2. Direct current (DC)

____ 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

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

What is the correct behavior before passing a level crossing that is not provided with a signaling device? (Cross Test)

Description : Slow down, if necessary stop, make sure that a railway vehicle is approaching. It is always necessary to stop and only pass through the rails with due care.

Last Answer : Slow down and, if necessary, stop to make sure the vehicle is approaching.

How do you spell signaling?

Description : How do you spell signaling?

Last Answer : The US spelling is signaled, while the UK variant is signalled.

Eicosanoids mediate inflammation in a variety of ways. Of the following statements, which are true with regard to this? a. Eicosanoids are stored in cytoplasmic granules for release after receptor mediated signaling b. Eicosanoids include prostaglandins, thromboxanes, leukotrienes and lipoxins c. Eicosanoids generally have a plasma half-life measured in hours d. Physiologic responses to eicosanoids include vasodilatation, vasoconstriction, increased vascular permeability and both chemotaxis and chemoattractant inhibition

Description : Eicosanoids mediate inflammation in a variety of ways. Of the following statements, which are true with regard to this? a. Eicosanoids are stored in cytoplasmic granules ... include vasodilatation, vasoconstriction, increased vascular permeability and both chemotaxis and chemoattractant inhibition

Last Answer : Answer: b, d The eicosanoids are derived from arachidonic acid (eicosatetraenoic acid) and consist of prostaglandins, thromboxanes, leukotrienes and lipoxins. The eicosanoids are not ... nervous system d. Mononuclear phagocytes release a variety of proinflammatory cytokines and growth factors

Which of the following is not a way of minimizing if not eliminating noise? A. Use redundancy B. Increase transmitted power C. Reduce signaling rate D. Increase channel bandwidth

Description : Which of the following is not a way of minimizing if not eliminating noise? A. Use redundancy B. Increase transmitted power C. Reduce signaling rate D. Increase channel bandwidth

Last Answer : D. Increase channel bandwidth

An interfering current in a telegraph or signaling channel due to telegraph or signaling current by another channel. A. Crosstalk B. Noise current C. Crossfire D. Intermodulation

Description : An interfering current in a telegraph or signaling channel due to telegraph or signaling current by another channel. A. Crosstalk B. Noise current C. Crossfire D. Intermodulation

Last Answer : C. Crossfire

A quadrature signaling have ________ possible states. A. 16 B. 8 C. 32 D. 4

Description : A quadrature signaling have ________ possible states. A. 16 B. 8 C. 32 D. 4

Last Answer : D. 4

Theprotocol that isused for signaling in the telephone network is called ______. A) POP B) SSS C) SS7 D) none of the above

Description : Theprotocol that isused for signaling in the telephone network is called ______. A) POP B) SSS C) SS7 D) none of the above

Last Answer : SS7

In ________signaling,a portionof the bandwidthis usedfor signaling and another portionfor data. A) in-band B) out-of-band C) mixed D) none of the above

Description : In ________signaling,a portionof the bandwidthis usedfor signaling and another portionfor data. A) in-band B) out-of-band C) mixed D) none of the above

Last Answer : out-of-band

In______signaling, the samecircuit is used for both signaling and data. A) in-band B) out-of-band C) mixed D) none of the above

Description : In______signaling, the samecircuit is used for both signaling and data. A) in-band B) out-of-band C) mixed D) none of the above

Last Answer : in-band

The technique in which a congested node stops receiving data from the immediate upstream node or nodes is called as _______ A. Admission policy B. Backpressure C. Forward signaling D. Backward signaling

Description : The technique in which a congested node stops receiving data from the immediate upstream node or nodes is called as _______ A. Admission policy B. Backpressure C. Forward signaling D. Backward signaling

Last Answer : B. Backpressure

Describe the various signalling techniques. Compare in-channel signalling with common channel signaling, which is more advantageous.

Description : Describe the various signalling techniques. Compare in-channel signalling with common channel signaling, which is more advantageous.

Last Answer : Signaling systems link the variety of switching systems, transmission systems and subscriber equipments in telecommunication network to enable the network to function as a whole. Three forms of signaling are ... for passing control signals for a group of trunks or information       

Write short notes on: i. Stored Program Control. ii. Congestion. iii. Common channel signaling. iv. PSTN.

Description : Write short notes on: i. Stored Program Control. ii. Congestion. iii. Common channel signaling. iv. PSTN.

Last Answer : (i) Stored Program Control: In centralized control, all the control equipment is replaced by a single processor which must be quite powerful. It must be capable of processing 10 to 100 calls ... the combination of lines and switches that from a system of electrical routes through the network.  

Write short note on Associated vs. Common channel signaling.

Description : Write short note on Associated vs. Common channel signaling.

Last Answer : Associated vs Common channel signalling: The out band signalling suffers from the very limited bandwidth. Both are capable of having only a small signal repertoire. The trend in modern networking ... economic implementation and simple assignment of trunk groups to signalling channels.   

SPC stands (A) Standard Protocol Control (B) Stored Program Control (C) Signaling and switching Centre (D) Signaling Process Center

Description : SPC stands (A) Standard Protocol Control (B) Stored Program Control (C) Signaling and switching Centre (D) Signaling Process Center

Last Answer : (B) Stored Program Control

Common channel signalling______________ (A) Uses the speech or data path for signaling. (B) Does not use the speech or data path for signaling. (C) Needs no additional transmission facilities. (D) Finds it difficult to handle signaling during speech.

Description : Common channel signalling______________ (A) Uses the speech or data path for signaling. (B) Does not use the speech or data path for signaling. (C) Needs no additional transmission facilities. (D) Finds it difficult to handle signaling during speech.

Last Answer : (C) Needs no additional transmission facilities.

The phase relationship between signaling elements for BPSK is the optimum signaling format and occurs only when two binary signal levels are allowed and when one signal is the exact negative of the other

Description : The phase relationship between signaling elements for BPSK is the optimum signaling format and occurs only when two binary signal levels are allowed and when one signal is the exact negative of the other

Last Answer : Antipodal signaling

In a temporary signaling arrangements for a bridge work in BG section, speed board shall be placed in advance of 30 m from the a) C.L. of the bridge b) Termination Board c) Start of the bridge/work spot* d) Caution Board

Description : In a temporary signaling arrangements for a bridge work in BG section, speed board shall be placed in advance of 30 m from the a) C.L. of the bridge b) Termination Board c) Start of the bridge/work spot* d) Caution Board

Last Answer : c) Start of the bridge/work spot*

.In a temporary signaling arrangements for a bridge work in BG section, caution board shall be placed in advance of ……. m from start of the bridge/ work spot. a) 30 m b) 1200 m* c) 677 m d) 1000 m

Description : .In a temporary signaling arrangements for a bridge work in BG section, caution board shall be placed in advance of ……. m from start of the bridge/ work spot. a) 30 m b) 1200 m* c) 677 m d) 1000 m

Last Answer : b) 1200 m*

What are integrins and do they influence cell-cell signaling?

Description : What are integrins and do they influence cell-cell signaling?

Last Answer : Integrins are a diverse family of transmembrane proteins consisting of alpha and beta subunits that are found in all animal cells. Integrins link the actin cytoskeleton to the ... movement, and can thus influence actin cytoskeleton dynamics and intracellular signaling of neighboring cells.

What are gap junctions and how do they contribute to cell-cell signaling?

Description : What are gap junctions and how do they contribute to cell-cell signaling?

Last Answer : Gap junctions are specialized connections that form a pore between adjacent cells, which permit small molecules and ions to move from one cell to another. In this way, gap junctions provide metabolic and electrical coupling between cells.

List several side-to-side cellular junctions that can influence cell signaling.

Description : List several side-to-side cellular junctions that can influence cell signaling.

Last Answer : Gap junctions, desmosomes, adherens junctions, integrin connections

What types of signaling molecules bind to and activate RTKs?

Description : What types of signaling molecules bind to and activate RTKs?

Last Answer : Growth factors, hormones, some extracellular matrix proteins, some cell surface proteins (i.e. ephrin)

Why do ion channels contribute to faster cellular responses than other signaling mechanisms, such as GPCR-mediated signaling?

Description : Why do ion channels contribute to faster cellular responses than other signaling mechanisms, such as GPCR-mediated signaling?

Last Answer : Ion channels generate electrical signals, which signals travel much more rapidly than chemical signals that depend on the process of molecular diffusion. An electrical signal can traverse the entire length of a nerve cell within milliseconds.

Briefly, describe how GPCR and heterotrimeric G protein-mediated signaling occurs.

Description : Briefly, describe how GPCR and heterotrimeric G protein-mediated signaling occurs.

Last Answer : Binding of a signaling molecule (ligand) to GPCRs causes a conformation change in GPCR, leading to heterotrimeric G protein activation, where GTP physically replaces the GDP bound to the alpha ... some G proteins stimulate the activity of target proteins, whereas others G proteins are inhibitory.

Which of the following are true in the context of Manchester Coding Signaling ?

Description : Which of the following are true in the context of Manchester Coding Signaling ?  (A) It suppresses the DC component  (B) It suppresses the high frequency component  (C) Pulses are unit symbol wide  (D) Symbol “1” is represented by positive pulse

Last Answer : Which of the following are true in the context of Manchester Coding Signaling ?  (A) It suppresses the DC component  (B) It suppresses the high frequency component  (C) Pulses are unit symbol wide  (D) Symbol “1” is represented by positive pulse

How do you transmit through multiplexing, a thousand of voice channel information over a single fiber optic using on e wavelength? A. Polar division B. Time division C. Fiber division D. Frequency division

Description : How do you transmit through multiplexing, a thousand of voice channel information over a single fiber optic using on e wavelength? A. Polar division B. Time division C. Fiber division D. Frequency division

Last Answer : B. Time division

What are the advantages of AC over DC?

Description : What are the advantages of AC over DC?

Last Answer : a. For the same capacity alternators are cheaper than DC generators, because alternator is not having commutator arrangement and there by small in size. b. Alternating current produces pulsating magnetic field and ... motor requires very less maintenance. g. Charge per unit for AC is less than DC.