Thermal circuit breaker has?

by

1 Answer

Answer :

Thermal circuit breaker has delayed trip action.

by

Related questions

The arc temperature in Oil Circuit Breaker may reach up to_______.

Description : 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 

The number of cycles in which a high speed circuit breaker can complete its operation is

Description : 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

A circuit breaker is designed to protect an electrical circuit from damage caused by :

Description : 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

The Minimum Oil Circuit Breaker (MOCB) is named because of :

Description : 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 

For selecting a circuit breaker, ______ should be determined.

Description : 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) 

ln a minimum oil circuit breaker the oil is used

Description : 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

Arc in a circuit breaker is interrupted at?

Last Answer : Arc in a circuit breaker is interrupted at zero current.

The arc voltage produced in A.C. circuit breaker is always?

Last Answer : The arc voltage produced in A.C. circuit breaker is always in phase with the arc current.

In a circuit breaker the basic problem is to?

Last Answer : In a circuit breaker the basic problem is to transmit large power.

Ionization in circuit breaker is facilitated by?

Last Answer : Ionization in circuit breaker is facilitated by high temperature, increase of mean free path, increasing field strength.

The voltage appearing across the contacts after opening of the circuit breaker is called______voltage.

Last Answer : The voltage appearing across the contacts after opening of the circuit breaker is called recovery voltage.

Air blast circuit breaker is used for?

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

Magnetic circuit breaker has ______ trip action.

Last Answer : Magnetic circuit breaker has instantaneous trip action.

The arcing contacts in a circuit breaker are made of?

Last Answer : The arcing contacts in a circuit breaker are made of copper tungsten alloy.

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.

Explain about Circuit Breaker

Description : 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.

How to Reset a Circuit Breaker

Description : 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.

How to Install a Circuit Breaker

Description : 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.

Explain working of static AC circuit breaker.

Description : 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.

Explain working of AC circuit breaker using SCR with circuit diagram.

Description : 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.

State function of starter and ELCB. (Earth Leakage Circuit Breaker)

Description : 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.

Breaking capacity of a circuit breaker is usually expressed in terms of

Description : 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

The arc voltage in a circuit breaker is :

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

Which of the following is used in a circuit breaker as the medium in which the arc forms?

Description : 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

Thermal overload relays are used to protect the motor against over current due to?

Last Answer : Thermal overload relays are used to protect the motor against overcurrent due to heavy loads.

A thermal protection switch can protect against?

Last Answer : A thermal protection switch can protect against overload.

Explain the thermal triggering method of SCR. Enlist different triggering methods of SCR.

Description : Explain the thermal triggering method of SCR. Enlist different triggering methods of SCR.

Last Answer : Types of Triggering: 1) Forward voltage triggering 2) Thermal triggering (Temperature triggering) 3) Radiation triggering (Light triggering) 4) dv/dt triggering 5) Gate triggering ... generated leakage current increases. This current gets multiplied internally and thyristor is turned on. 

Define thermal runaway.

Description : Define thermal runaway.

Last Answer : Thermal runaway  The problem with increasing temperature causing increasing collector current is that more current increase the power dissipated by the transistor which, in turn, increases its temperature ... self-reinforcing cycle is known as thermal runaway, which may destroy the transistor. 

Classify condensers used in thermal power station. Explain each type in brief.

Description : Classify condensers used in thermal power station. Explain each type in brief. 

Last Answer : Types of condenser: Classification: 1. Jet Condenser (Mixing Type) 2. Surface condenser (non Mixing type)  Explanation:-   1. Jet Condenser (Mixing Type) In Jet condenser the steam ... there in no direct contact between the steam and cooling water. This condensate is reused in boiler. 

"Efficiency of thermal power station is low". — Justify.

Description : "Efficiency of thermal power station is low". — Justify. 

Last Answer : Justification: Efficiency of thermal power station is low":- Overall efficiency of T.P.P depends upon efficiency of boiler, turbine and alternator. The heat produced due to combustion of coal ... losses in thermal power plant is 71%, So efficiency of thermal power plant is less about 29% 

State advantages of Pulverized coal w.r.t. thermal power plant.

Description : State advantages of Pulverized coal w.r.t. thermal power plant. 

Last Answer : Advantages of Pulverized coal w.r.t. thermal power plant.  1. Due to pulvarization amount of fuel required to produce same amount of heat reduces. 2. Time required for combution reduces ... of air and thorough mixing of air and fuel, very high-combustion temperatures can be attained.

State the function of super heater of a thermal power plant.

Description : State the function of super heater of a thermal power plant. 

Last Answer : Function of Super heater: -  Its function is to increase the temperature of steam by absorbing heat from exhausted hot flue gases.

Describe thermal runaway of transistor and explain how it can be avoided.

Description : Describe thermal runaway of transistor and explain how it can be avoided.

Last Answer : Concept of thermal runaway:  1.We know that  IC = β IB + (1+ β) ICO  Where ICO is the leakage current and ICO is strongly dependent on temperature. 2. Leakage current approximately doubles for ...   Thermal runaway can be avoided by : 1) Using stabilization circuitry 2) Heat sink 

State the function of cooling tower and condenser in thermal power station.

Description : State the function of cooling tower and condenser in thermal power station.

Last Answer : 1. Condenser:   Function of condenser is to convert exhaust steam again into water by reducing its temperature with the help of cold water. Also it reduces back pressure of steam turbine 2 ... tower : The function of cooling tower is to reduce the temperature of water coming from condenser.

Write any four advantages and four disadvantages of thermal power plant.

Description : Write any four advantages and four disadvantages of thermal power plant.

Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

Explain ash disposal and dust collection in a thermal power plant.

Description : Explain ash disposal and dust collection in a thermal power plant.

Last Answer : Ash disposal:-  Various methods of disposal of ash are:  Mechanical handling system.  Pneumatic system. Hydraulic system  Steam jet system  Commonly used ash handling ... be done either manually or automatically.  This removed fly ash is collected in separate container

State any four factors governing Selection of site for thermal power station.

Description : State any four factors governing Selection of site for thermal power station. 

Last Answer : Following Factors are to be considered:- 1. It should locate near coal mine. 2. Sufficient quantity of water should be available. 3. Sufficient large space should be available. 4. It should be located ... laws of the land and the town planning. 14. The interests of national defense must be served.

The overall efficiency of Thermal Power Plant is equal to _______________ .

Description : The overall efficiency of Thermal Power Plant is equal to _______________ .  (A) Regenerative Cycle Efficiency (B) Renkine Cycle Efficiency (C) Carnot cycle efficiency (D) None of the above

Last Answer : The overall efficiency of Thermal Power Plant is equal to Regenerative Cycle Efficiency. 

In a thermal power plant, ash is collected in

Description : In a thermal power plant, ash is collected in

Last Answer : In a thermal power plant, ash is collected in hoppers or bunkers

The unit heat rate characteristic of a thermal power unit shows :

Description : The unit heat rate characteristic of a thermal power unit shows :  (A) Heat input per kWh of output versus the megawatt output of unit  (B) Heat input per kW of output versus the megawatt output ... hour output of unit  (D) Heat input per kW of output versus the megawatt hour output of unit

Last Answer : The unit heat rate characteristic of a thermal power unit shows : Heat input per kWh of output versus the megawatt output of unit 

If the % reactance upto the fault point is 20%, then the short circuit current will be

Description : 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

Which of the following circuit breakers has high reliability & minimum maintenance?

Description : 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 

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

A fuse in a motor circuit provides protection against?

Last Answer : A fuse in a motor circuit provides protection against short-circuit and overload.

Air blast circuit breakers for 400 kV power system are designed to operate in?

Last Answer : Air blast circuit breakers for 400 kV power system are designed to operate in 50 millisecond.

The short circuit in any winding of the transformer is the result of?

Last Answer : The short circuit in any winding of the transformer is the result of impulse voltage.

The time of closing the cycle, in modern circuit breakers is?

Last Answer : The time of closing the cycle, in modern circuit breakers is 0.003 sec.

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.

Circuit breakers are essentially?

Last Answer : Circuit breakers are essentially current carrying contacts called electrodes.

Circuit breakers usually operate under?

Last Answer : Circuit breakers usually operate under transient state of short-circuit current.