Please Log in or Register for more.


153 views

1 Answer

Answer :

Thermal circuit breaker has delayed trip action.

Like 0 like

Please log in or register to answer this question.

Related Questions


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 

Show More

117 views 1 answer







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

Show More

637 views 1 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
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

Show More

106 views 1 answer







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 

Show More

162 views 1 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) 
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) 

Show More

78 views 1 answer







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

Show More

83 views 1 answer








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

Show More

83 views 1 answer








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

Show More

315 views 1 answer








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

Show More

121 views 1 answer








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

Show More

304 views 1 answer








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

Show More

419 views 1 answer








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

Show More

78 views 1 answer








Last Answer : Magnetic circuit breaker has instantaneous trip action.

Show More

217 views 1 answer








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

Show More

116 views 1 answer







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.

Show More

95 views 2 answers







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.

Show More

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.

Show More

10 views 1 answer







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.

Show More

13 views 1 answer







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.

Show More

209 views 1 answer







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.

Show More

936 views 1 answer







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.

Show More

457 views 1 answer







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

Show More

268 views 1 answer







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

Show More

134 views 1 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
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

Show More

116 views 1 answer








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

Show More

253 views 1 answer








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

Show More

233 views 1 answer







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. 

Show More

220 views 1 answer







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. 

Show More

69 views 1 answer







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. 

Show More

136 views 1 answer







"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% 

Show More

105 views 1 answer







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.

Show More

98 views 1 answer







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.

Show More

87 views 1 answer







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 

Show More

540 views 2 answers







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.

Show More

315 views 1 answer







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%; }

Show More

168 views 3 answers







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

Show More

90 views 1 answer







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.

Show More

187 views 2 answers







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. 

Show More

445 views 1 answer







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

Show More

112 views 1 answer







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 

Show More

80 views 1 answer







What is thermal runaway of a transistor?

Show More

78 views 0 answers







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

Show More

3.0k views 1 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 
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 

Show More

298 views 1 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
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

Show More

109 views 1 answer








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

Show More

157 views 1 answer








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

Show More

209 views 1 answer








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

Show More

174 views 1 answer








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

Show More

123 views 1 answer







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.

Show More

437 views 1 answer








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

Show More

327 views 1 answer






Show More⇦ PreviousNext ⇨