1 Answer

Answer :

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

Related questions

Description : What is the purpose of Overload Protection in a motor circuit?

Last Answer : Ans. The Overload Protection is used in a motor circuit to protect it from sustained over currents.

Description : A fuse wire should have :  (A) Low specific resistance and high melting point (B) Low specific resistance and low melting point (C) High specific resistance and high melting point (D) High specific resistance and low melting point

Last Answer : A fuse wire should have : High specific resistance and low melting point

Description : ln HRC fuse the time between cut-off and final current zero is called

Last Answer : ln HRC fuse the time between cut-off and final current zero is called the arcing time

Last Answer : The fuse blows off by melting.

Last Answer : The fuse rating is expressed in terms of current.

Last Answer : H.R.C. fuse, as compared to a rewirable fuse, has no ageing effect, high speed of operation, high rupturing capacity.

Last Answer : A fuse is connected in series with circuit.

Last Answer : The material used for fuse must have low melting point and high specific resistance.

Last Answer : The main function of a fuse is to prevent excessive currents.

Description : A relay used for protection of motors against overload is :  (A) Impedance relay (B) Electromagnetic attraction type (C) Thermal relay (D) Buchholz's relay

Last Answer : D

Description : For protection of rotating machines against lightning surges _______ is used.  (1) lightning arrester (2) capacitor (3) combination of lightning arrester and capacitor (4) lightning conductor and arrester

Last Answer : For protection of rotating machines against lightning surges combination of lightning arrester and capacitor is used. 

Description : Reactance relay is normally preferred for protection against

Last Answer : Reactance relay is normally preferred for protection against earth faults

Description : Surge absorbers are used for protection against

Last Answer : Surge absorbers are used for protection against low voltage high frequency oscillations

Last Answer : The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.

Last Answer : For the protection of power station buildings against direct strokes the requirements are interception, conduction and dissipation.

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

Last Answer : If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens this will make armature to take heavy current, possibly burning it.

Last Answer : Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a magnetic relay.

Description : Blind spot is a point in the zones of protection where

Last Answer : Blind spot is a point in the zones of protection where No protection is available.

Description : A negative sequence relay is used for protection of  (1) Generator (3) Motor (2) Transformer (4) Long Transmission lines

Last Answer : A negative sequence relay is used for protection of Generator 

Last Answer : Protection by fuses is generally not used beyond 100 A .

Last Answer : Overfluxing protection is recommended for generator transformer of the power plant.

Last Answer : Over voltage protection is recommended for hydro-electric generators, steam turbine generators, gas turbine generators.

Last Answer : The single phasing relays are used for the protection of three phase motors.

Last Answer : Discrimination between main and back up protection is provided by the use of relays which are slow.

Last Answer : The delay fuses are used for the protection of motors.

Description : Primary and Backup Protection

Last Answer : Primary and Backup Protection  B,D,G,I are the primary protection. A,C,H,J are the backup protection. About 90% of faults are clear by Primary Protection. So ... ordinated backup (primary is at various station  and backup is at control room with computer)

Description : What is fuse?

Last Answer : Ans. Fuse is used to protect an electric circuit when the rated current exceeds in the circuit the fuse wire melts and opens the circuit.

Description : State any two advantages of MCB over Fuse. State the standard specifications of MCB available in the market.  

Last Answer : Following advantages of MCB over Fuse: 1. No need of replacement of fuse wire. 2. Manually restore of supply is simple. 3. Fault understanding by visual inspection 4. More safe than fuse The standard specifications of ... 6A, 10A,16A,20A, 25A, 30A, 32A, 40A, 50A, 60A and 63A 6. 250V and 450 v

Description : State the material used for making (1) Magnetic Core (2) Fuse element  

Last Answer : The material used for making of:  (1) Magnetic Core : Iron, cobalt, Nickel, CRGO, HRGO , silicon steel  (2) Fuse Element: Tin- lead wire, Tinned copper wire 

Description : Write applications of each of the following:(i) Fuse (ii) MCB (iii) MCCB.

Last Answer : i) Applications of fuse:  * Used in domestic installations to provide short circuit protection.  * Used in commercial / Industrial installations to provide overload and short circuit protection.  * Used in ...  * Rectifiers panels,  * U.P.S, Electronic equipment,  * Motors,  * Furnaces

Description : Give the function of fuse and switch.

Last Answer : Functions of fuse:  * To break the circuit under fault condition.  * To provide overcurrent protection to the circuit.  * To provide short circuit protection to the circuit.  * To provide ...  * To make the electric circuit manually.  * To break the electric circuit manually.

Description : What is a fuse ?

Last Answer :  A Fuse is a protective device which prevent overloading of current in a circuit.

Description : what is HRC fuse?

Last Answer : HRC (High Rupturing Capacity) fuse HRC fuse is High Rupturing Capacity fuse. At the time of fault it disconnect the circuit very fast. Filling powder is silica sand. No flashover ... speed response Reliable No maintenance CheaperDisadvantages:- We have to replace it manually after each operation.

Description : Can anyone recommend a good, durable protection case for iPod Touch 4th gen?

Last Answer : I would highly recommend an Otterbox case. I have the Defender series case for my 3gen iPod touch. It's not perfect, but it provides better protection than any other case I've seen, and I like the ... ago, but that was only because I dropped my iPod and the case cracked. The ipod was fine though.

Description : Car Leather Protection

Last Answer : Your girlfriend and your leather car interior have many things in common. Both are tough but incredibly sensitive. Both are cold and are very hard to please. Both need a lot of attention and ... differences too. Unlike your girlfriend, leather is not something you want to get down and dirty with.

Description : Explain in detail over-voltage protection.

Last Answer : Over-voltage protection: Over-voltage protection to the thyristor is provided using: i) R-C Snubber circuit ii) Non-linear resistor Thyrector A) Snubber Circuit: It is basically a ... returns to its high resistance state. Thyrector is normally placed across the supply terminals.

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

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 

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 

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

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

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

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 

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) 

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Description : ln a minimum oil circuit breaker the oil is used

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

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

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

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