1 Answer

Answer :

The voltage used for suburban trains in D.C. system is usually 600 to 750 V.

Related questions

Last Answer : The rate of acceleration on suburban or urban service is in the range 1.6 to 4.0 km phps.

Last Answer : In main line service as compared to urban and suburban service distance between the stops is more, maximum speed reached is high, acceleration and retardation rates are low.

Last Answer : The rate of acceleration on suburban or urban services is restricted by the consideration of Passenger Discomfort.

Description : Why are DC motors used in trains and not AC motors ?

Last Answer : The reason is torque. torque is inversely proportional to speed..i.e when th knowe train comes to rest position to motion.. initial speed is zero..so it requires high starting torque for ... current will flow through field and armature coils then maximum torque is available at the intial condition.

Description : Describe the reason of using dc series motor for electric trains.

Last Answer : Electric trains require an inverse torque speed characteristics for proper operation. That is a higher torque is required at start (when speed is nil or low) and as the train picks up ... torque - speed characteristics of DC series motors match, these motors are suitable for electric trains

Description : Do electric trains have gears?

Last Answer : Electric  trains  have  gears  for  speed  variation. This  is  because  it  is  not  easy  to  run  a  motor  at  diffrent  speed  of your  choice.

Description : The frequencies and voltage used in Dielectric heating are (A) 10 – 30 MHz, upto 25 kV (B) 50 – 60 Hz, upto 25 kV (C) 10 – 30 MHz, upto 100 V (D) 50 – 60 Hz, 110 V – 230 V

Last Answer : The frequencies and voltage used in Dielectric heating are 10 – 30 MHz, upto 25 kV

Last Answer : The braking retardation is usually in the range 10 to 15 km phps.

Last Answer : Overload capacity of diesel engines is usually restricted to 2 percent.

Description : A differentiator is not usually used in control system, because it : - (A) reduces damping  (B) increases error  (C) reduces gain margin  (D) increases input noise

Last Answer : A differentiator is not usually used in control system, because it : - increases input noise

Description : List standard voltage level used in India. 

Last Answer : Standard voltage level used in India: * Generation Voltage : 3.3KV, 6.6KV,11KV and 17.5 KV,21KV (Now a days generation voltage is in the range of 11KV- 33KV) * Primary Transmission voltage :- 220 ... voltages in India are 765 KV (750KV), 400KV, 220KV, 132KV, 110KV, 66KV, 33KV, 22KV, 11KV.

Description : An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be  (1) unaffected (2) decreased (3) increased (4) either decreased or increased depending on the direction of the DC field

Last Answer : An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be either decreased or increased depending on the direction of the DC field

Last Answer : The under voltage relay can be used for generators, busbars, transformers, motors.

Description : What equipment is used to measure voltage?

Last Answer : Voltmeter is used to measure voltage.

Description : The permissible voltage variation in transmission and distribution system is:  (A) ± 0.1% (B) ± 1% (C) ±10% (D) ± 25%

Last Answer : The permissible voltage variation in transmission and distribution system is: ±10%

Description : Which of the following is the least expensive protection for over current in low voltage system?  (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

Last Answer : Which of the following is the least expensive protection for over current in low voltage system?  (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

Description : In voltage source converter based HVDC transmission system the active power is controlled by changing (A) phase angle of the converter ac input voltage (B) supply frequency of the converter ac input voltage (C) magnitude of the converter ac input voltage (D) DC voltage at the inverter terminals

Last Answer : In voltage source converter based HVDC transmission system the active power is controlled by changing phase angle of the converter ac input voltage

Description : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is (A) 28.2 mm (B) 26.4 mm (C) 24.4 mm (D) 22.0 mm

Last Answer : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is 22.0 mm

Description : For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is

Last Answer : For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is 25 x 25

Last Answer : The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to extinguish the arc.

Last Answer : Commonly used instruments in power system measurement are induction.

Description : Limitation and application of High Voltage DC (HVDC)

Last Answer : Limitation and application of High Voltage DC (HVDC) :  Limitation:- 1) It is difficult to step up and step down DC voltage like AC voltage. 2) Special cooling ... conventional/non-conventional) 12) Increasing existing grid utilization. 13) Interconnection of different grids or networks

Description : Is the power line voltage available in our homes a dc or an ac voltage?

Last Answer : The power line voltage available in our homes is AC. Mobile dwellings are the most commonly DC-supplied homes and even then they tend to include AC supply for heavier loads.

Description : A dc chopper is fed from a constant voltage mains the duty ratio of chopper is progressively increased while the chopper feeds an RL load. The per unit current ripple would  (1) increase progressively  (2 ... 0.5 and then increase  (4) increase to a maximum value at α = 0.5 and then decrease

Last Answer : A dc chopper is fed from a constant voltage mains the duty ratio of chopper is progressively increased while the chopper feeds an RL load. The per unit current ripple would increase to a maximum value at α = 0.5 and then decrease

Description : Identify the increasing order of voltage regulation of the following dc generators a same load :  (A) differential compound, shunt and under compound  (B) shunt, differential compound and ... C) under compound, shunt and differential compound  (D) shunt, under compound and differential compound

Last Answer : Identify the increasing order of voltage regulation of the following dc generators a same load : under compound, shunt and differential compound 

Description : A DC voltage source is connected across a series RLC circuit. Under steady-state conditions, the applied DC voltage drops entirely across the

Last Answer : A DC voltage source is connected across a series RLC circuit. Under steady-state conditions, the applied DC voltage drops entirely across the C only

Description : A circuit that binds the upper or lower extreme of a waveform to a fixed DC voltage level is called ______ A) DC voltage restorer B) Clamping circuit C) Both A and B D) None of these

Last Answer : A circuit that binds the upper or lower extreme of a waveform to a fixed DC voltage level is called ______ A) DC voltage restorer B) Clamping circuit C) Both A and B D) None of these

Description : A d.c. source has an open circuit voltage of 30 V and an internal resistance of 1.5 Ohm. A resistive load is connected to the source. Maximum power dissipated in the load is (A) 300 W (B) 150 W (C) 45 W (D) 20 W

Last Answer : A d.c. source has an open circuit voltage of 30 V and an internal resistance of 1.5 Ohm. A resistive load is connected to the source. Maximum power dissipated in the load is 150 W

Last Answer : In a level compounded D.C. generator, full load terminal voltage is equal to no-load terminal voltage.

Last Answer : The armature voltage control of D.C. motor provides constant torque drive.

Description : In a dc machine, interpoles are used to  (1) neutralize the effect of armature reaction in the interpolar region (2) generate more induced emf in the armature (3) avoid interference of the armature flux with the main -field flux (4) reduce the demagnetizing effect of armature reaction

Last Answer : In a dc machine, interpoles are used to neutralize the effect of armature reaction in the interpolar region

Last Answer : D.C. shunt motors are used for driving machine tools.

Last Answer : In D.C. machines fractional pitch winding is used to reduce the sparking.

Last Answer : Starters are used with D.C. motors because to restrict armature current as there is no back e.m.f. while starting.

Description : How is a thyristor used to convert AC to DC?

Last Answer : thyristor

Description : Power factor of an inductive circuit is usually improved by connecting capacitor to it in?

Last Answer : Power factor of an inductive circuit is usually improved by connecting capacitor to it in parallel.

Last Answer : In a A.C. series motor armature coils are usually connected to commutator through resistance.

Last Answer : The power factor of a single-phase induction motor is usually lagging.

Last Answer : In a shaded pole motor, the shading coil usually consist of a single turn of heavy copper wire which is short-circuited and carries only induced current.

Last Answer : The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.

Description : Is the sound from the warning alert system?

Last Answer : Sure seems like it. He looked down and the hit some buttons after hearing it. It was like a beep that he had reached a speed.

Description : The arc voltage in a circuit breaker is :

Last Answer : The arc voltage in a circuit breaker is : in phase with the arc current

Description : What are some mundane inventions, that, after years of taking them for granted, at some point saved your bacon?

Last Answer : Seat belts for vehicles. Public wash rooms.

Description : Is there a way to look up railroad crossing train times?

Last Answer : My railroad is Amtrak and can sometimes run 45 minutes to and hour late. Good luck with avoiding crossing by calculating when they’ll be at a crossing.

Description : What happens with abandoned railroad scrap?

Last Answer : When they took up the tracks on the backside of my property, I got the land, they took the rails for recycling, the ties were free for the taking by anyone who wanted them.

Description : I am on a train travelling at 100 mph.I jump up from a standing position,why do i land on the same spot?Why have i not landed further down the train?

Last Answer : Because you’re also going 100 mph.

Description : how does a train stay on the tracks?

Last Answer : Gravity.

Description : The motor used for electric traction is  (1) D.C. shunt motor (3) D.C. series motor  (2) D.C. compound motor (4) Synchronous motor

Last Answer : The motor used for electric traction is D.C. series motor

Description : Spot welding is used for (1) Thin metal (3) Castings only (2) Rough and irregular surface (4) Thick sections

Last Answer : Spot welding is used for Thin metal

Description : The electrode rod used for welding uses a coating on it 

Last Answer : The electrode rod used for welding uses a coating on it  to give a vapour to serve as a shielding gas to protect the weld area from atmospheric contamination and to provide slag to protect the welded area