For interrupting capacitive currents which Circuit Breaker (CB) is used a) SF6 CB b) Oil CB c) Vacuum CB d) Air blast CB

For interrupting capacitive currents which Circuit Breaker (CB) is used
a) SF6 CB
b) Oil CB
c) Vacuum CB
d) Air blast CB
by

1 Answer

Answer :

Ans: Vacuum CB
by

Related questions

Which of the following circuit breakers has high reliability and minimum maintenance ? (a) Air blast circuit breakers (b) Circuit breaker with SF6 gas (c) Vacuum circuit breakers (d) Oil circuit breakers

Description : Which of the following circuit breakers has high reliability and minimum maintenance ? (a) Air blast circuit breakers (b) Circuit breaker with SF6 gas (c) Vacuum circuit breakers (d) Oil circuit breakers

Last Answer : (b) Circuit breaker with SF6 gas

Air blast circuit breaker is used for (a) over currents (b) short duty (c) intermittant duty (d) repeated duty

Description : Air blast circuit breaker is used for (a) over currents (b) short duty (c) intermittant duty (d) repeated duty

Last Answer : (d) repeated duty

Which of the following medium is employed for extinction of arc in air circuit breaker ? (a) Water (b) Oil (c) Air (d) SF6

Description : Which of the following medium is employed for extinction of arc in air circuit breaker ? (a) Water (b) Oil (c) Air (d) SF6

Last Answer : (c) Air

What are the advantages of air blast circuit breaker over oil circuit breaker?

Description : What are the advantages of air blast circuit breaker over oil circuit breaker?

Last Answer : o The risk of fire is diminished o The arcing time is very small due to rapid buildup of dielectric strength between contacts o The arcing products are completely removed by the blast whereas oil deteriorates with successive operations

What Is Sf6 Circuit Breaker?

Description : What Is Sf6 Circuit Breaker?

Last Answer : SF6 is Sulpher hexa Flouride gas.. if this gas is used as arc quenching medium in a Circuitbreaker me SF6 CB.

What is the purpose of compressed air in SF6 breaker?

Description : What is the purpose of compressed air in SF6 breaker?

Last Answer : This used for drive for opening and closing of the contacts. (Arc quenching is taken care by SF6 gas) 

The interrupting time of a circuit breaker is the period between the instant of

Description : The interrupting time of a circuit breaker is the period between the instant of  (A) initiation of short circuit and the arc extinction on an opening operation (B) energizing of the trip circuit ... of primary arc contacts (D) energizing of the trip circuit and the parting of primary arc contacts

Last Answer : The interrupting time of a circuit breaker is the period between the instant of energizing of the trip circuit and the arc extinction on an opening operation

What are the types of air blast circuit breaker?

Description : What are the types of air blast circuit breaker?

Last Answer : Arial-blast type Cross blast Radial-blast

What are the levels of SF6 gas in 220 kV breaker and their significance?

Description : What are the levels of SF6 gas in 220 kV breaker and their significance?

Last Answer : 7 kg/cm2 - normal pressure 5.2 bar - alarm 5.0 bar - closing/tripping operation blocked. 

Describe the construction of SF6 circuit breaker with neat diagram.

Description : Describe the construction of SF6 circuit breaker with neat diagram.

Last Answer : Construction of SF6 Circuit Breaker : A sulphur hexafluoride (SF6) circuit breaker consists of fixed and moving contacts enclosed in a chamber. The chamber is called arc interruption ... contact, moving contact and arcing horn are coated with a copper-tungsten arc-resistant material. 

Explain construction and working of SF6 circuit breaker.

Description : Explain construction and working of SF6 circuit breaker.

Last Answer : Construction: A sulphur hexafluoride (SF6) circuit breaker consists of fixed and moving contacts enclosed in a chamber. The chamber is called arc interruption chamber, which contains the ... arc being extinguished. Finally the gas enters the contact space increasing the dielectric strength.

what is SF6 circuit breaker?

Description : what is SF6 circuit breaker?

Last Answer : SF6 is Sulpher hexa Fluoride gas. If this gas is used as arc quenching medium in a Circuit breaker means SF6 CB.

Why we use Vacuum Circuit Breaker in High Transmission System and not Air Circuit Breaker?

Description : Why we use Vacuum Circuit Breaker in High Transmission System and not Air Circuit Breaker?

Last Answer : A:Vacuum has high arc quenching property compare to air . The dielectric strength of vacuum is equal to 8 times than air . Hence vacuum circuit breaker is used in High voltage line and air circuit breaker is used in low voltage lines.

An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. cause the slip rings to melt C. cause a low voltage differential to develop between the armature and the bus D. cause high currents to be induced in the field windings

Description : An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. ... between the armature and the bus D. cause high currents to be induced in the field windings

Last Answer : Answer: D

Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling? A. The rotor of the loaded alternator will hunt. B. Severe cross currents will occur which could cause damage. C. The rotor of the incoming alternator will stop. D. Both alternators will parallel 180° out of phase.

Description : Which of the following problems will occur if the circuit breaker of the incoming alternator is closed and it is 180° out of phase with the loaded alternator when paralleling? A. The rotor of the ... The rotor of the incoming alternator will stop. D. Both alternators will parallel 180° out of phase.

Last Answer : Answer: B

The arc resulting from the tripping of a circuit breaker is prevented from damaging the contacts by _____________. A. designing the contacts to open slowly B. directing the arc into an arc chute C. an inverse timed thermal trip for short circuit currents D. instantaneous magnetic trip for overload currents

Description : The arc resulting from the tripping of a circuit breaker is prevented from damaging the contacts by _____________. A. designing the contacts to open slowly B. directing the arc into an ... an inverse timed thermal trip for short circuit currents D. instantaneous magnetic trip for overload currents

Last Answer : Answer: B

Air blast circuit breaker is used for?

Last Answer : Air blast circuit breaker is used for repeated duty.

Periodic testing of circuit breakers is necessary to assure that a correctly rated and properly installed unit _________________. A. can trip faster as it increases in age B. will continue to provide the original degree of protection C. does not exceed its interrupting capacity D. be able to withstand at least 125% of applied voltage

Description : Periodic testing of circuit breakers is necessary to assure that a correctly rated and properly installed unit _________________. A. can trip faster as it increases in age B. will continue to provide ... not exceed its interrupting capacity D. be able to withstand at least 125% of applied voltage

Last Answer : Answer: B

What is vacuum circuit breaker? Define with cause and where be use it Device?

Description : What is vacuum circuit breaker? Define with cause and where be use it Device?

Last Answer : A breaker is normally used to break a circuit. While breaking the circuit, the contact terminals will be separated. At the time of separation an air gap is formed in between the terminals. Due to ... CB is having vacuum pressure the arc formation is interrupted. VCB's can be used up to 11kv.

What are the disadvantages of MOCB over a bulk oil circuit breaker?

Description : What are the disadvantages of MOCB over a bulk oil circuit breaker?

Last Answer : o The degree of carbonization is increased due to smaller quantity of oil o There is difficulty of removing the gases from the contact space in time o The dielectric strength of the oil deteriorates rapidly due to high degree of carbonization.

What are the advantages of MOCB over a bulk oil circuit breaker?

Description : What are the advantages of MOCB over a bulk oil circuit breaker?

Last Answer : • It requires lesser quantity of oil • It requires smaller space • There is a reduced risk of fire • Maintenance problem are reduced

Fuses are rated in _____________. A. voltage B. amperage C. interrupting capacity D. all the above

Description : Fuses are rated in _____________. A. voltage B. amperage C. interrupting capacity D. all the above

Last Answer : Answer: D

What is the use of vacuum breaker?

Description : What is the use of vacuum breaker? 

Last Answer : In case of loss of seal oil to generator seals vacuum breaker is used to bring TG to rest very quickly.

The electrical diagram shown in the illustration is used to depict a/an ____________. EL-0015 A. resistance circuit B. inductive circuit C. stepdown circuit D. capacitive circuit

Description : The electrical diagram shown in the illustration is used to depict a/an ____________. EL-0015 A. resistance circuit B. inductive circuit C. stepdown circuit D. capacitive circuit

Last Answer : Answer: D

An AC circuit has a capacitive reactance of 30 ohms in addition to an inductive reactance of 40 ohms connected in series. What is the reactance of the circuit? A. 8.37 ohms B. 10.00 ohms C. 50.00 ohms D. 70.00 ohms

Description : An AC circuit has a capacitive reactance of 30 ohms in addition to an inductive reactance of 40 ohms connected in series. What is the reactance of the circuit? A. 8.37 ohms B. 10.00 ohms C. 50.00 ohms D. 70.00 ohms

Last Answer : Answer: B

In the illustrated circuit, one advantage of the capacitor coupling over direct coupling is ____________. EL-0048 A. as the frequency decreased the capacitive reactance (Xc) increases B. the amplifier becomes more efficient at lower capacitance. C. the arrangement allows the coupling of the signal while it isolates the biasing of each stage. D. good frequency response.

Description : In the illustrated circuit, one advantage of the capacitor coupling over direct coupling is ____________. EL-0048 A. as the frequency decreased the capacitive reactance (Xc) increases B. the amplifier becomes ... of the signal while it isolates the biasing of each stage. D. good frequency response.

Last Answer : Answer: C

Voltage will always lead current in a/an ______________. A. capacitive circuit B. inductive circuit C. magnetic circuit D. resistive circuit

Description : Voltage will always lead current in a/an ______________. A. capacitive circuit B. inductive circuit C. magnetic circuit D. resistive circuit

Last Answer : Answer: B

Decreasing the frequency in a capacitive circuit while maintaining a constant circuit voltage, will result in a/an _____________. A. increase in apparent power B. decrease in circuit current C. decrease in capacitive reactance D. decrease in total impedance

Description : Decreasing the frequency in a capacitive circuit while maintaining a constant circuit voltage, will result in a/an _____________. A. increase in apparent power B. decrease in circuit current C. decrease in capacitive reactance D. decrease in total impedance

Last Answer : Answer: B

An AC circuit has capacitance arranged in series. If the line voltage remains constant, the capacitive reactance value can be varied by changing the _____________. A. line frequency B. resistance C. number of commutating poles D. number of interpoles

Description : An AC circuit has capacitance arranged in series. If the line voltage remains constant, the capacitive reactance value can be varied by changing the _____________. A. line frequency B. resistance C. number of commutating poles D. number of interpoles

Last Answer : Answer: A

The component labeled 'CR1' in the circuit shown in the illustration __________________. EL-0085 A. varies its anode/cathode polarity depending on 'RL' current B. rectifies the varying voltage from the collector of 'Q1' C. acts as a low capacitive reactance to smooth ripple D. establishes a constant reference voltage for the base of 'Q1'

Description : The component labeled 'CR1' in the circuit shown in the illustration __________________. EL-0085 A. varies its anode/cathode polarity depending on 'RL' current B. rectifies the varying voltage from the ... reactance to smooth ripple D. establishes a constant reference voltage for the base of 'Q1'

Last Answer : Answer: D

The combined effect of inductive reactance, capacitive reactance, and resistance in an AC series circuit is known as _____________. A. reactance B. total reactance C. impedance D. resonance

Description : The combined effect of inductive reactance, capacitive reactance, and resistance in an AC series circuit is known as _____________. A. reactance B. total reactance C. impedance D. resonance

Last Answer : Answer: C

AC circuits possess characteristics of resistance, inductance, and capacitance. The capacitive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Description : AC circuits possess characteristics of resistance, inductance, and capacitance. The capacitive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: A

In series RLC circuit at resonant a) Voltage is in phase with current b) Current is maximum c) Inductive reactance = Capacitive reactance d) All of the above

Description : In series RLC circuit at resonant a) Voltage is in phase with current b) Current is maximum c) Inductive reactance = Capacitive reactance d) All of the above

Last Answer : Ans: All of the above

Air Blast Circuit Breakers Advantages Disadvantages

Description : Air Blast Circuit Breakers Advantages Disadvantages

Last Answer : Air Blast Circuit Breakers Advantages Disadvantages In air blast circuit breakers, compressed air at a pressure of 20-30 kg/cm2 is employed as an arc quenching medium. Air blast circuit breakers ... air blast circuit breaker current chopping problem exists There is a problem of re-striking voltage

The current zero interruption, in oil and air blast circuit breakers, is achieved by (a) lengthening of the gap (b) cooling and blast effect (c) both (a) and (b) (d) deionizing the oil with forced air (e) none of the above

Description : The current zero interruption, in oil and air blast circuit breakers, is achieved by (a) lengthening of the gap (b) cooling and blast effect (c) both (a) and (b) (d) deionizing the oil with forced air (e) none of the above

Last Answer : (c) both (a) and (b)

On which of the following routine tests are conducted ? (a) Oil circuit breakers (b) Air blast circuit breakers (c) Minimum oil circuit breakers (d) All of the above

Description : On which of the following routine tests are conducted ? (a) Oil circuit breakers (b) Air blast circuit breakers (c) Minimum oil circuit breakers (d) All of the above

Last Answer : (d) All of the above

The current zero interruption, in oil and air blast circuit breakers, is achieved by?

Description : The current zero interruption, in oil and air blast circuit breakers, is achieved by?

Last Answer : The current zero interruption, in oil and air blast circuit breakers, is achieved by lengthening of the gap, cooling and blast effect.

Which of the listed precautions should be taken when cleaning the internals of a motor with compressed air? A. Open the machine on both ends so as to allow the air and dust to escape. B. Be certain that the circuit breaker is opened and tagged on the feeder panel. C. Be certain that the air is clean and as dry as possible. D. All of the above.

Description : Which of the listed precautions should be taken when cleaning the internals of a motor with compressed air? A. Open the machine on both ends so as to allow the air and dust to escape. B. Be certain that the ... panel. C. Be certain that the air is clean and as dry as possible. D. All of the above.

Last Answer : Answer: D

Which of the following is the least expensive protection for overcurrent is low voltage system ? (a) Rewireable fuse (b) Isolator (c) Oil circuit breaker (d) Air break circuit breaker (e) None of the above

Description : Which of the following is the least expensive protection for overcurrent is low voltage system ? (a) Rewireable fuse (b) Isolator (c) Oil circuit breaker (d) Air break circuit breaker (e) None of the above

Last Answer : (a) Rewireable fuse

Write down specification and applications of Air blast C. B. and Vacuum C. B.

Description : Write down specification and applications of Air blast C. B. and Vacuum C. B.

Last Answer : Specifications of Circuit Breaker: i) Service type: Indoor / Outdoor ii) No. of Poles: 1 or 3 iii) Nominal System Voltage: iv) Highest System Voltage: v) Rated normal current; vi) ... Vacuum Circuit Breaker: Vacuum circuit breakers are used in electrical systems operating at 11kV, 25kV and 33kV.

The horizontal line which cuts across 'L1' shown in figure 'A' of the illustration indicates a/an ______________. EL-0091 A. iron core B. saturable core C. air gap D. capacitive coupling

Description : The horizontal line which cuts across 'L1' shown in figure 'A' of the illustration indicates a/an ______________. EL-0091 A. iron core B. saturable core C. air gap D. capacitive coupling

Last Answer : Answer: B

What are the characteristic of SF6 gas?

Description : What are the characteristic of SF6 gas?

Last Answer : It has good dielectric strength and excellent arc quenching property. It is inert, non-toxic, noninflammable and heavy. At atmospheric pressure, its dielectric strength is 2.5 times that of air. At three times atmospheric pressure, its dielectric strength is equal to that of the transformer oil.

What is meant by electro negativity of SF6 gas?

Description : What is meant by electro negativity of SF6 gas?

Last Answer : SF6 has high affinity for electrons. When a free electron comes and collides with a neutral gas molecule, the electron is absorbed by the neutral gas molecule and negative ion is formed. This is called as electro negativity of SF6 gas.

What are the properties of SF6 gas?

Description : What are the properties of SF6 gas?  

Last Answer : This is inert gas. Odorless, non-toxic, colourless, stable, non-inflammable and density is more hence high dielectric strength. The special property of this gas is Electro negativity. This gas ... more slow in conduction, so that resistance in medium is increases and get arc get extinguishes. 

What is the significance of SF6 gas pressure in 6.6kV breakers?

Description : What is the significance of SF6 gas pressure in 6.6kV breakers?

Last Answer : Density gauge Green – correct SF6 pressure (3 –3.5bar) Yellow – pressure for breaking system fault current (refilling should be done) Red – SF6 pressure less than 2 bar, which indicates leak in the system. 

What are the properties of SF6 gas?

Description : What are the properties of SF6 gas?  

Last Answer : Physical properties 1. Colourless 2. Odorless 3. Non-toxic. Pure SF6 gas is not harmful to the health. 4. Non-inflammable. 5. Density- more gas density, 5 times ... advantages offer increased safety, reduction in size, weight, noiseless operation, easy installation, handling and maintenance. 

Which of the listed pairs of materials make the best insulators? A. dry air and a vacuum B. tin and lead C. doped silicon and germanium D. paper and oil

Description : Which of the listed pairs of materials make the best insulators? A. dry air and a vacuum B. tin and lead C. doped silicon and germanium D. paper and oil

Last Answer : Answer: D

The following is/are the characteristics of SF6 circuit breakers:

Description : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above

Last Answer : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above