The arc voltage in a circuit breaker is :
Last Answer : The arc voltage in a circuit breaker is : in phase with the arc current
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134 views
1 answer
asked
Apr 29, 2018
by
anonymous

The arc temperature in Oil Circuit Breaker may reach up to_______. (A) 5,000° K (B) 8,000° K (C) 10,000° K (D) None of the above
Last Answer : The arc temperature in Oil Circuit Breaker may reach up to 5,000° K
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117 views
1 answer
asked
May 8, 2018
by
anonymous

Last Answer : Arc in a circuit breaker is interrupted at zero current.
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83 views
1 answer
asked
Mar 20, 2018
by
anonymous

Which of the following is used in a circuit breaker as the medium in which the arc forms? A) Insulating gas B) Insulating oil C) Vacuum D) All the above
Last Answer : Which of the following is used in a circuit breaker as the medium in which the arc forms? A) Insulating gas B) Insulating oil C) Vacuum D) All the above
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116 views
1 answer
asked
Apr 29, 2018
by
anonymous

Last Answer : The voltage appearing across the contacts after opening of the circuit breaker is called recovery voltage.
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418 views
1 answer
asked
Mar 20, 2018
by
anonymous

Arc in a circuit behaves as?
Last Answer : Arc in a circuit behaves as a resistance decreasing with voltage rise across the arc.
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284 views
1 answer
asked
Mar 19, 2018
by
anonymous

The number of cycles in which a high speed circuit breaker can complete its operation is (A) 3 to 8 (B) 10 to 18 (C) 20 to 30 (D) 40 to 50
Last Answer : The number of cycles in which a high speed circuit breaker can complete its operation is 3 to 8
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637 views
1 answer
asked
May 8, 2018
by
anonymous

A circuit breaker is designed to protect an electrical circuit from damage caused by : (A) Over load (B) Short circuit (C) Over current (D) All of the above
Last Answer : A circuit breaker is designed to protect an electrical circuit from damage caused by : (A) Over load (B) Short circuit (C) Over current (D) All of the above
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106 views
1 answer
asked
May 8, 2018
by
anonymous

The Minimum Oil Circuit Breaker (MOCB) is named because of : (A) Reduced requirement of oil (B) Reduced requirement of air (C) All of the above (D) None of the above
Last Answer : The Minimum Oil Circuit Breaker (MOCB) is named because of : Reduced requirement of oil
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161 views
1 answer
asked
May 8, 2018
by
anonymous

For selecting a circuit breaker, ______ should be determined. (A) initial current that flows on occurrence of a short circuit only (B) transient current that flows at the time of circuit interruption only (C) resonant frequency only (D) (A) and (B)
Last Answer : For selecting a circuit breaker, ______ should be determined. (A) initial current that flows on occurrence of a short circuit only (B) transient current that flows at the time of circuit interruption only (C) resonant frequency only (D) (A) and (B)
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78 views
1 answer
asked
Apr 30, 2018
by
anonymous

ln a minimum oil circuit breaker the oil is used
Last Answer : ln a minimum oil circuit breaker the oil is used to act as circuit breaking medium only
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83 views
1 answer
asked
Apr 26, 2018
by
anonymous

Last Answer : In a circuit breaker the basic problem is to transmit large power.
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121 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Ionization in circuit breaker is facilitated by high temperature, increase of mean free path, increasing field strength.
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304 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Air blast circuit breaker is used for repeated duty.
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78 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Magnetic circuit breaker has instantaneous trip action.
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217 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Thermal circuit breaker has delayed trip action.
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153 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : The arcing contacts in a circuit breaker are made of copper tungsten alloy.
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116 views
1 answer
asked
Mar 19, 2018
by
anonymous

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.
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94 views
2 answers
asked
Dec 4, 2017
by
anonymous

Explain about Circuit Breaker
Last Answer : Ans: CIRCUIT BREAKERS: In the case of outdoor type installation, the circuit breakers have fixed location and the station layout is such that adequate section clearances are always available from ... carried out as above, every circuit breaker will be completely overhauled after five year interval.
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24 views
1 answer

How to Reset a Circuit Breaker
Last Answer : How to Reset a Circuit Breaker All is well with the lights and your electrical appliances one minute, then everything falls into pitch-black darkness the next moment. When a room in your house ... electrical fires. With these tips, a power surge does not have to be a permanent inconvenience.
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10 views
1 answer
asked
May 15, 2021
by
anonymous

How to Install a Circuit Breaker
Last Answer : How to Install a Circuit Breaker A circuit breaker is an essential component of a home's electric system. When power surges occur, it trips then shuts off the electricity, preventing ... -functional electrical system. Just make sure you take proper safety precautions when installing this device.
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13 views
1 answer
asked
May 14, 2021
by
anonymous

Explain working of static AC circuit breaker.
Last Answer : Static AC Circuit breaker: The circuit configuration of static AC circuit breaker using SCR is shown in the figure. When switch S' is closed, the SCRs T1 and T2 are fired in positive ... non-availability of gate current. Thus the maximum time delay for breaking the circuit is one half-cycle.
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208 views
1 answer
asked
May 21, 2020
by
anonymous

Explain working of AC circuit breaker using SCR with circuit diagram.
Last Answer : AC Circuit Breaker: The circuit configuration of static AC circuit breaker using SCR is shown in the figure. When switch S' is closed, the SCRs T1 and T2 are fired in positive ... to non-availability of gate current. Thus the maximum time delay for breaking the circuit is one half-cycle.
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936 views
1 answer
asked
Oct 13, 2019
by
anonymous

State function of starter and ELCB. (Earth Leakage Circuit Breaker)
Last Answer : i) Function of Starter:- 1. To prevent the high starting current OR to minimize the starting current. 2. To give supply failure protection 3. To give over load and short circuit protection ... an installation and cut off the circuit from power supply and avoid electrical shock to the person.
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456 views
1 answer
asked
Sep 18, 2018
by
anonymous

Breaking capacity of a circuit breaker is usually expressed in terms of (1) Ampere (2) Volts (3) MW (4) MVA
Last Answer : Breaking capacity of a circuit breaker is usually expressed in terms of MVA
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268 views
1 answer
asked
Apr 30, 2018
by
anonymous

Source transformation Replace the circuit with voltage source in series with a single resistor
Last Answer : Source transformation Replace the circuit with voltage source in series with a single resistor
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247 views
1 answer
asked
Mar 21, 2020
by
anonymous

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
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334 views
1 answer
asked
Apr 29, 2018
by
anonymous

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
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2.0k views
1 answer
asked
Apr 29, 2018
by
anonymous

What is the RMS voltage in a series RL circuit, if the voltage across R and L is 256 V and 192 V respectively? A) 320 V B) 448 V C) 64 V D) None of these
Last Answer : What is the RMS voltage in a series RL circuit, if the voltage across R and L is 256 V and 192 V respectively? A) 320 V B) 448 V C) 64 V D) None of these
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145 views
1 answer
asked
Apr 29, 2018
by
anonymous

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
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105 views
1 answer
asked
Apr 29, 2018
by
anonymous

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
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289 views
1 answer
asked
Apr 25, 2018
by
anonymous

What should I get for my first welder, arc or stick?
Last Answer : ‘pends, I think you should get the arc.
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0 views
1 answer
asked
Feb 27
by
anonymous

Compare the AC and DC Arc lamps.
Last Answer : AC Arc Lamp DC Arc Lamp Cross section area of electrode is same Cross section area of electrode is positive rod is twice that of negative rod Series inductor is used for stability ... supply is used for DC arc lamp Luminous efficiency is less Luminous efficiency is high
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247 views
1 answer
asked
May 3, 2020
by
anonymous

Compare between Resistance welding and Arc welding on any six points.
Last Answer : Sr.No Parameters Resistance Welding Arc Welding 1 Type of welding Plastic/Pressure/Non-fusion welding Fusion/Non pressure welding 2 Principle of heat developed Heat ... It is suitable for mass production It is suitable for heavy job, maintenance and repair work
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112 views
1 answer
asked
Oct 12, 2018
by
anonymous

Write the purpose of coal and ash handling unit. Also write different activities that arc carried out in this unit.
Last Answer : Purpose of coal and ash handling unit :- To transport coal from coal storage to power plant. A large quantity of ash about 10 to 30 % produced in furnace, the removal of ash from boiler furnace ... disposed off. Various methods of disposal of ash: Mechanical system. Pneumatic system.
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56 views
1 answer
asked
Sep 8, 2018
by
anonymous
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Arc resistance (1) increases with increase in arc current (2) decrease with increase in arc current (3) is independent of arc current (4) is independent of arc length
Last Answer : Arc resistance decrease with increase in arc current
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76 views
1 answer
asked
May 1, 2018
by
anonymous

For arc welding current range is usually (1) 10 to 15 A (2) 30 to 40 A (3) 50 to 100 A (4) 100 to 350 A
Last Answer : For arc welding current range is usually 100 to 350 A
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184 views
1 answer
asked
Apr 30, 2018
by
anonymous

Identify the correct combination of respective Electric arc welding and Electric resistance welding methods : (A) Butt welding and Seam welding (B) Hydrogen shielding and Projection welding (C) Seam welding and Coated electrode welding (D) Coated electrode welding and Hydrogen shielding
Last Answer : Identify the correct combination of respective Electric arc welding and Electric resistance welding methods : (A) Butt welding and Seam welding (B) Hydrogen shielding and Projection welding ... Seam welding and Coated electrode welding (D) Coated electrode welding and Hydrogen shielding
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162 views
1 answer
asked
Apr 30, 2018
by
anonymous

The supply for arc welding is :
Last Answer : The supply for arc welding is : Low voltage, high current ac or dc voltage
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93 views
1 answer
asked
Apr 29, 2018
by
anonymous

Refer to the circuit below. The total absorbed (consumed) power is:
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19 views
0 answers

A battery of e.m.f. 12V supplies a current of 5A for 2 minutes. How much energy is supplied in this time?
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30 views
0 answers

The arc voltage produced in A.C. circuit breaker is always (a) in phase with the arc current (b) lagging the arc current by 90" (c) leading the arc current by 90° (d) none of the above
Last Answer : (a) in phase with the arc current
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30 views
1 answer

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 : Which of the following medium is employed for extinction of arc in air circuit breaker ?(a) Water (b) Oil(c) Air (d) SF6
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325 views
1 answer
asked
May 26, 2018
by
anonymous
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If the % reactance upto the fault point is 20%, then the short circuit current will be
Last Answer : If the % reactance upto the fault point is 20%, then the short circuit current will be 5 times the full load current
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3.0k views
1 answer
asked
May 8, 2018
by
anonymous

Which of the following circuit breakers has high reliability & minimum maintenance? (A) Bulk oil type CB (B) Air blast CB (C) Vacuum CB (D) Sulphur hexafluoride CB
Last Answer : Which of the following circuit breakers has high reliability & minimum maintenance? (A) Bulk oil type CB (B) Air blast CB (C) Vacuum CB (D) Sulphur hexafluoride CB
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296 views
1 answer
asked
May 8, 2018
by
anonymous

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
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108 views
1 answer
asked
May 8, 2018
by
anonymous

Last Answer : A fuse in a motor circuit provides protection against short-circuit and overload.
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157 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Air blast circuit breakers for 400 kV power system are designed to operate in 50 millisecond.
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209 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The short circuit in any winding of the transformer is the result of impulse voltage.
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174 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The time of closing the cycle, in modern circuit breakers is 0.003 sec.
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123 views
1 answer
asked
Mar 20, 2018
by
anonymous
