In order to reduce the harmful effects of harmonics on the A.C. side of a high voltage D.C. transmission system ______are provided. (A) synchronous condensers (B) shunt capacitors (C) shunt filters (D) static compensators

In order to reduce the harmful effects of harmonics on the A.C. side of a high voltage
D.C. transmission system ______are provided.
 (A) synchronous condensers (B) shunt capacitors
(C) shunt filters (D) static compensators
by

1 Answer

Answer :

Ans: C
 Xc= 1/ ωc
by

Related questions

In order to reduce the harmful effects of harmonics on the AC side of a high voltage DC transmission system...

Description : In order to reduce the harmful effects of harmonics on the AC side of a high voltage DC transmission system_____ are provided. (A) synchronous condensers (B) shunt capacitors (C) shunt filters (D) static compensators

Last Answer : In order to reduce the harmful effects of harmonics on the AC side of a high voltage DC transmission system shunt filters are provided. 

Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for 'across-the-line starting' C. provide a backup means of voltage regulation for emergency starting D. allow the voltage to be either stepped up or down, depending on the application, to ensure full torque

Description : Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for ' ... to be either stepped up or down, depending on the application, to ensure full torque

Last Answer : Answer: A

The voltage drop, for constant voltage transmission is compensated by installing (a) inductors (b) capacitors (c) synchronous motors (d) all of above (e) none of the above

Description : The voltage drop, for constant voltage transmission is compensated by installing (a) inductors (b) capacitors (c) synchronous motors (d) all of above (e) none of the above

Last Answer : (c) synchronous motors

Disc compensators are provided in large diameter fuel gas carrying pipelines to (A) Keep the pipe in proper orientation (B) Make the pipe joint leak-proof (C) Account for contraction/expansion of pipe due to temperature changes of the surroundings (D) Account for the pressure variation side the pipeline

Description : Disc compensators are provided in large diameter fuel gas carrying pipelines to (A) Keep the pipe in proper orientation (B) Make the pipe joint leak-proof (C) Account for contraction/expansion ... due to temperature changes of the surroundings (D) Account for the pressure variation side the pipeline

Last Answer : (C) Account for contraction/expansion of pipe due to temperature changes of the surroundings

In order to improve the power factor ___ device is employed in the substation a) Synchronous condenser b) Synchronous reactor c) Series Capacitors d) None of the above

Description : In order to improve the power factor ___ device is employed in the substation a) Synchronous condenser b) Synchronous reactor c) Series Capacitors d) None of the above

Last Answer : Ans: A

In a distribution system, in order to improve power factor, the synchronous capacitors are installed?

Last Answer : In a distribution system, in order to improve power factor, the synchronous capacitors are installed at the receiving end.

A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected, this is caused by _____________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. capacitors inside the meter storing charges

Description : A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected, this is caused by _____________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. capacitors inside the meter storing charges

Last Answer : Answer: A

The length cf air gap to be provided in ______ is primarily determined by power factor consideration. (a) d.c. series motor . (b) d.c. shunt motor (c) induction motor (d) synchronous motor

Description : The length cf air gap to be provided in ______ is primarily determined by power factor consideration. (a) d.c. series motor . (b) d.c. shunt motor (c) induction motor (d) synchronous motor

Last Answer : (c) induction motor

The Bandwidth of an RC-coupled amplifier is limited by: A) coupling capacitors at the low frequency end and bypass capacitors at the high frequency end B) coupling capacitors at the high frequency end and bypass capacitors at the low frequency end C) bypass and coupling capacitors at the low frequency end and shunt capacitors at the high frequency end and D) shunt capacitors at the low frequency end and bypass as well as coupling capacitors at the high frequency end.

Description : The Bandwidth of an RC-coupled amplifier is limited by: A) coupling capacitors at the low frequency end and bypass capacitors at the high frequency end B) coupling capacitors at the high frequency ... at the low frequency end and bypass as well as coupling capacitors at the high frequency end.

Last Answer : C) bypass and coupling capacitors at the low frequency end and shunt capacitors at the high frequency end and

What type of electric motor is commonly used to start small auxiliary diesel engines? A. synchronous B. series C. shunt D. cage

Description : What type of electric motor is commonly used to start small auxiliary diesel engines? A. synchronous B. series C. shunt D. cage

Last Answer : Answer: B

The speed-torque characteristics of a DC series motor are approximately similar to those of the _________motor. (A) universal (B) synchronous (C) DC shunt (D) two-phase

Description : The speed-torque characteristics of a DC series motor are approximately similar to those of the _________motor. (A) universal (B) synchronous (C) DC shunt (D) two-phase

Last Answer : Ans: A Universal motor has same characteristics as DC series motor and also known as an a.c series motor.

A motor which can conveniently be operated at lagging as well as leading power factors is the (A) squirrel cage induction motor. (B) wound rotor induction motor. (C) synchronous motor. (D) DC shunt motor.

Description : A motor which can conveniently be operated at lagging as well as leading power factors is the (A) squirrel cage induction motor. (B) wound rotor induction motor. (C) synchronous motor. (D) DC shunt motor.

Last Answer : (C) synchronous motor.

What kind of concerns is associated with temperature pinch points in condensers?

Description : What kind of concerns is associated with temperature pinch points in condensers?

Last Answer : Be extra careful when condensers are designed with a small pinch point. A pinch point is the smallest temperature difference on a temperature vs heat content plot that shows both streams. If the actual ... is 8 0F, there can be a 16% drop in heat transfer. Source: Gulley Computer Associates

To limit the current flow through a DC voltmeter to as low a value as possible, the moving coil circuit is provided with a/an _____________. A. high series resistance B. high parallel resistance C. series inductor D. external shunt

Description : To limit the current flow through a DC voltmeter to as low a value as possible, the moving coil circuit is provided with a/an _____________. A. high series resistance B. high parallel resistance C. series inductor D. external shunt

Last Answer : Answer: A

What for series and shunt compensation provided in EHV transmission lines?

Description : What for series and shunt compensation provided in EHV transmission lines?

Last Answer : Answer: Series capacitance is provided in EHV lines to artificially reduce the series reactance of the line so as to improve stability, voltage regulation and transmission efficiency Shunt compensation ... reduce the line susceptance so as to improve the voltage regulation under light load condition

In a substation the following equipment is not installed (a) exciters (b) series capacitors (c) shunt reactors (d) voltatre transformers

Description : In a substation the following equipment is not installed (a) exciters (b) series capacitors (c) shunt reactors (d) voltatre transformers

Last Answer : (a) exciters

Which of the following equipment, for regulating the voltage in distribution feeder, will be most economical ? (a) Static condenser (b) Synchronous condenser (c) Tap changing transformer (d) Booster transformer

Description : Which of the following equipment, for regulating the voltage in distribution feeder, will be most economical ? (a) Static condenser (b) Synchronous condenser (c) Tap changing transformer (d) Booster transformer

Last Answer : (d) Booster transformer

When replacing component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its base B. there is a danger of phosphor poisoning should 'B''s bulb break C. component 'D' must be closed during the replacement to provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Description : When replacing component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its ... provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Last Answer : Answer: D

Capacitors are used on the output of the power supply in today's consoles to _____________. A. filter out 'ripple' B. prevent overloads C. act as a permanent load D. decrease the average value of the output voltage

Description : Capacitors are used on the output of the power supply in today's consoles to _____________. A. filter out 'ripple' B. prevent overloads C. act as a permanent load D. decrease the average value of the output voltage

Last Answer : Answer: A

When changing out component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its base B. there is a danger of phosphor poisoning should 'B''s bulb break C. component 'D' must be closed during the replacement to provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Description : When changing out component 'B' of the circuit shown in the illustration, it is important to know that ____________. EL-0081 A. it is polarity sensitive and must be inserted as indicated on its ... provide the capacitor's initial charge D. it must match the circuit voltage and component 'C' wattage

Last Answer : Answer: D

Two contributors of electronic console failures are heat and vibration. To combat some of their effects, preventive maintenance procedures should include ______________. A. systematic rotation of circuit cards with those from spares to allow component cooling B. periodic changing or cleaning of console ventilation and control room air conditioning filters C. weekly tightening of console foundation bolts and changing of the air in the control room D. all of the above

Description : Two contributors of electronic console failures are heat and vibration. To combat some of their effects, preventive maintenance procedures should include ______________. A. systematic rotation of circuit cards with those ... bolts and changing of the air in the control room D. all of the above

Last Answer : Answer: B

______are designed specifically for capturing, creating, editing and manipulating images? A. Spreadsheets B. Word Processor C. Image Editors D. None of the above

Description : ______are designed specifically for capturing, creating, editing and manipulating images? A. Spreadsheets B. Word Processor C. Image Editors D. None of the above

Last Answer : C. Image Editors

The contents of ______are lost when the computer turns off: a) storage b) input c) output d) memory e) None of The Above

Description : The contents of ______are lost when the computer turns off: a) storage b) input c) output d) memory e) None of The Above

Last Answer : d) memory

On an engine throttle control system, the auxiliary control circuits are provided with devices to prevent excessive overtravel of the pilot valve by the synchronous motor. These devices are called _________________. A. overlap sensors B. limit switches C. overtravel relays D. proximity switches

Description : On an engine throttle control system, the auxiliary control circuits are provided with devices to prevent excessive overtravel of the pilot valve by the synchronous motor. These devices are called _________________. A. overlap sensors B. limit switches C. overtravel relays D. proximity switches

Last Answer : Answer: B

What is the proper procedure for suppressing electrical noise in a mobile station? A. Apply shielding and filtering where necessary B. Insulate a all plain sheet metal surfaces from each other C. Apply anti-static spray liberally to all nonmetallic D. Install filter capacitors in series with all dc wiring

Description : What is the proper procedure for suppressing electrical noise in a mobile station? A. Apply shielding and filtering where necessary B. Insulate a all plain sheet metal surfaces from each other C. ... -static spray liberally to all nonmetallic D. Install filter capacitors in series with all dc wiring

Last Answer : A. Apply shielding and filtering where necessary

How harmonics generated in electrical power distribution system?

Description : How harmonics generated in electrical power distribution system?

Last Answer : Harmonic frequencies are integral multiples of the fundamental supply frequency, i.e. for a fundamental of 50 Hz, the third harmonic would be 150 Hz and the fifth harmonic would be 250 ... the corresponding application guides, since the electricity grid's protection system should cut off the fault.

What are the disadvantages of the harmonics present in the inverter system?

Description : What are the disadvantages of the harmonics present in the inverter system?

Last Answer : a. Harmonic currents will lead to excessive heating in the induction motors. This will reduce the load carrying capacity of the motor. b. If the control and the regulating circuits are not ... affected. d. On critical loads, torque pulsation produced by the harmonic current can be useful.

The purpose of amortisseur windings in a synchronous motor is to ______________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor

Description : The purpose of amortisseur windings in a synchronous motor is to ______________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor

Last Answer : Answer: C

Amortisseur windings are installed in a synchronous motor to _____________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor

Description : Amortisseur windings are installed in a synchronous motor to _____________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor

Last Answer : Answer: C

While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. This indicates the _____________. A. motor has started properly B. field windings are grounded C. slip rings are dirty D. power transmission cables are grounded

Description : While starting a main propulsion synchronous motor, the ammeter pegs out at maximum and then returns to the proper value after synchronization. This indicates the _____________. A. motor has started ... field windings are grounded C. slip rings are dirty D. power transmission cables are grounded

Last Answer : Answer: A

What do you mean by harmonics?

Description : What do you mean by harmonics?

Last Answer : Definition for a harmonic is-a sinusoidal component of a periodic wave or quantity having a frequency that is an integral multiple of the fundamental frequency. The main sources of ... as they may cause overheating of capacitors and nearby generators and interfere with telecommunication systems.

What are the reasons for harmonics in the motor?

Description : What are the reasons for harmonics in the motor?

Last Answer : Generally even harmonics are not expected to be present in three phase motors. Triple-n harmonics like 3rd, 9th, 15th etc. are also not expected. The dominant odd harmonics expected are 5th ... harmonic winding faults, short circuits. Hot spots in rotor or stator also may indicate higher harmonics.

Harmonics are eliminated by using a) Skewing of rotor b) Distribution winding c) Short pitch winding d) All of the above

Description : Harmonics are eliminated by using a) Skewing of rotor b) Distribution winding c) Short pitch winding d) All of the above

Last Answer : Ans: All of the above

The introduction of interpoles in between the main pole improves the performance of d.c. machines, because (A) The interpole produces additional flux to augment the developed torque. (B) The flux waveform is improved with reduction in harmonics. (C) The inequality of air flux on the top and bottom halves of armature is removed. (D) A counter e.m.f. is induced in the coil undergoing commutation.

Description : The introduction of interpoles in between the main pole improves the performance of d.c. machines, because (A) The interpole produces additional flux to augment the developed torque. (B) The flux waveform is ... armature is removed. (D) A counter e.m.f. is induced in the coil undergoing commutation.

Last Answer : Ans: D Counter e.m.f is produced, it neutralizes the reactive emf.

The speed of a synchronous motor is varied by _____________. A. interchanging any two of the three live leads B. changing the voltage of the system C. changing the input frequency D. increasing the field excitation

Description : The speed of a synchronous motor is varied by _____________. A. interchanging any two of the three live leads B. changing the voltage of the system C. changing the input frequency D. increasing the field excitation

Last Answer : Answer: C

An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from _____________. A. one line terminal to each coil lead in succession B. one field coil to each adjacent field coil in turn C. any suitable ground to any available line lead D. any field pole to each field coil lead

Description : An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from ... C. any suitable ground to any available line lead D. any field pole to each field coil lead

Last Answer : Answer: A

A short in the shunt field of a DC motor is best located by _____________. A. visual inspection of the commutator B. applying AC voltage to each field coil and measuring the voltage drop across each field coil C. using a growler and hacksaw blade D. isolating each coil from the others and using a megohmmeter

Description : A short in the shunt field of a DC motor is best located by _____________. A. visual inspection of the commutator B. applying AC voltage to each field coil and measuring the voltage drop across ... using a growler and hacksaw blade D. isolating each coil from the others and using a megohmmeter

Last Answer : Answer: B

The direction of rotation of the winch shown in the illustration is changed by reversing the _____________. EL-0102 A. direction of current through the shunt field B. polarity of voltage at 'S1' and 'S2' C. direction of current through the armature D. polarity of voltage at 'L1' and 'L2'

Description : The direction of rotation of the winch shown in the illustration is changed by reversing the _____________. EL-0102 A. direction of current through the shunt field B. polarity of voltage at 'S1' and 'S2' C. direction of current through the armature D. polarity of voltage at 'L1' and 'L2'

Last Answer : Answer: C

One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for polarity using a/an ____________. A. iron bar across each field B. magnetic compass placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections

Description : One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for ... placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections

Last Answer : Answer: B

The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. separate exciter in a series with the shunt field C. carbon pile regulator in series with the load D. balance coil diverting neutral current through the shunt field

Description : The simplest method of controlling the terminal voltage of compound-wound DC generator is with a _____________. A. hand-operated field rheostat connected in series with the shunt field circuit B. ... in series with the load D. balance coil diverting neutral current through the shunt field

Last Answer : Answer: A

When 220V dc shunt alternator generating the voltage at rated value. If direction of rotation is reversed, then alternator will a) Build up its voltage with same polarity b) Build up its voltage with opposite polarity c) No build up of voltage d) None

Description : When 220V dc shunt alternator generating the voltage at rated value. If direction of rotation is reversed, then alternator will a) Build up its voltage with same polarity b) Build up its voltage with opposite polarity c) No build up of voltage d) None

Last Answer : Ans: No build up of voltage

Voltage feed back amplifier is a a) Shunt-Shunt b) Shunt-Series c) Series-Shunt d) Series- Series

Description : Voltage feed back amplifier is a a) Shunt-Shunt b) Shunt-Series c) Series-Shunt d) Series- Series

Last Answer : Ans: Shunt-Shunt

A d.c. shunt motor runs at no load speed of 1140 r.p.m. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full load speed in r.p.m. is (A) 1080 (B) 1203 (C) 1000 (D) 1200

Description : A d.c. shunt motor runs at no load speed of 1140 r.p.m. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full load speed in r.p.m. is (A) 1080 (B) 1203 (C) 1000 (D) 1200

Last Answer : (A) 1080

A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of the machine as a motor will be (A) 800 rpm. (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.

Description : A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of ... . (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.

Last Answer : (C) less than 800 rpm.

Which of Betnovate-C and fona plus gel is more harmful to the skin ? Which has more side effects ?

Description : Which of Betnovate-C and fona plus gel is more harmful to the skin ? Which has more side effects ?

Last Answer : These two creams are very effective for acne according to the advice of doctors. As far as I know, Fona Plus Gel is the best. You can safely use it. It also has fewer side effects.

Which of Betnovate-C and fona plus gel is more harmful to the skin ? Which has more side effects ? Which of these two should I use ?

Last Answer : These two creams are very effective for acne according to the advice of doctors. As far as I know, Fona Plus Gel is the best. You can safely use it. It also has fewer side effects.

For measurements on high voltage capacitors, the suitable bridge is?

Last Answer : For measurements on high voltage capacitors, the suitable bridge is Schering bridge.

A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Description : A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Last Answer : (a) series wound generator

A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Description : A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Last Answer : (a) series wound generator

To reduce short circuit fault currents are used. (a) reactors (b) resistors (c) capacitors (d) none of the above

Description : To reduce short circuit fault currents are used. (a) reactors (b) resistors (c) capacitors (d) none of the above

Last Answer : (a) reactors