Circuit Breaker Question & AnswersApril 1, 2023 By Wat Electrical This article lists 100 Circuit Breaker MCQs for engineering students. All the Circuit Breaker Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of Circuit Breaker.In large-scale or small-scale electrical appliances, there might be any situation where the electric device might break down or might lead to a short circuit damaging the interfaced devices in any environment. This leads to huge damage if not controlled at right time. Hence to protect these electrical devices from major breakdown, an electrical control device is designed named a circuit breaker. These devices are the major component or heart of any electrical system.A circuit breaker is a device that protects an electric circuit where high current flows. The names of the circuit breaker include fuse, OCPD, and switch. They are classified into different types such as air CB, oil CB, SF6 CB, Vacuum CB, and more based on their application.Their properties vary based on their design of CB. For example, a vacuum based circuit breaker where it has characteristics such as good interruption stabilizing the circuit and dielectric-based recovery. It benefits in terms of advantages of reliability, zero fire hazard, and zero noise. The applications of circuit breakers include plant protection, power sharing, and high current application.1). Which of the following electric parameter does a circuit breaker protects in an electric circuit? Current Voltage Resistance Impedance None Hint2). Which of the following are connections to circuit breakers? Power distribution grids Power plants Ground connects All the above None Hint3). A power plant ends are also called? Hot wire Cold wire Expanded wire Both a and b None Hint4). On which principle does a circuit breaker works on? Switch Diode Fuse All the above None Hint5). Which are the class of circuit breakers? AC CB DC CB HV CB All the above None Hint6). A circuit breaker operates ____ ways? Manually Automatically Un-interrupt Both a and b None Hint7). Which of the following is the function of circuit breaker? Control Protect Switch All the above None Hint8). A flow of maximum current over its limit causes ___ to the circuit? Equipment damage Network damage Short circuits All the above None Hint9). ___ happens while large quantity current interruption among switching? Large arcing Break down Shorting Zero bias condition None Hint10). A circuit type breaker comprises of ____ type of contacts? Fixed Dynamic Static All the above None Hint11). _____ type of stored energy type is present in an circuit breaker? Kinetic Potential Dynamic All the above None Hint12). How many conditions does a circuit breaker consist of? 1 2 3 4 None Hint13). In which condition of circuit breaker does contacts get in connects? Open Closed Short Both b and c None Hint14). Which of the following is the energy form a circuit breaker stores the energy? Metal spring deformation Air compressed Hydraulic based pressure All the above None Hint15). The energy in circuit breaker is volatile during? Source input Operation Load connection Both b and c None Hint16). The potential energy and circuit breaker speed are _________ proportional? Directly Indirectly Equal Constant None Hint17). Which of the following are the types of coils in circuit breaker? Tripping Close Open Both a and b None Hint18). The energy that is released in a circuit breaker is which form? kinetic Potential Constant Both a and b None Hint19). Which of the following components is responsible for storing potential energy charge in a circuit breaker? Spring charging based motor Air based compressor AC equipment All the above None Hint20). According to electrical principle a circuit breaker carries ___ type of current? Large rated Fault power based Small rated Both a and b None Hint21). Which are the ways to increase the dielectric strength based media in a circuit breaker contacts? Compress ionized arcing media Cooling arcing media Replacing ionized based arcing media via fresh gasses All the above None Hint22). ____ portion of process must be included in operation od circuit breaker? Quenching Pinching Breaking Both a and b None Hint23). ___ are the classifications of serviced based circuit breaker? Outdoor based circuit breaker Indoor based circuit breaker Hydraulic based circuit breaker Both a and b None Hint24). ______are the classifications of mechanism based circuit breaker? Outdoor based circuit breaker Indoor based circuit breaker Hydraulic based circuit breaker Both a and b None Hint25). Which of the following are the voltage based circuit breakers? High voltage based Low voltage based Medium voltage based All the above None HintCircuit Breaker MCQs for Students26). Which of the following are the quenching media based circuit breakers? Oil Air SF6 All the above None Hint27). Which of the following is the max temperature of oil based circuit breaker? 5000oK 500oK 100oK 20000oK None Hint28). Up to which condition the circuit breaker operates well? When resistance is sufficient When capacitance is well When inductance is good When charging happens None Hint29). Which situation does a circuit breaker prevents? Circuit cut-off Circuit threshold Circuit resistance Both a and b None Hint30). Which of the following are the components of circuit breaker? Electrodes Relay ARC All the above None HintRead more about Over load relay31). At which condition does arc principle in a circuit breaker occurs? Faulty condition Breakdown condition Constant operation condition All the above None Hint32). In a circuit breaker, when contacts are not connected then the area between contacts is _____? Decreased Increased Medium Closed None Hint33). ____ exists when gap between contacts occurs? Large potential Low potential High voltage High current None Hint34). What is the relation between potential variation and dielectric strength at the time of electron moment? Potential variation > dielectric strength Potential variation < dielectric strength Potential variation = dielectric strength Potential variation > 1/dielectric strength None Hint35). Which of the following are high voltage based circuit breakers? Oil circuit breaker Air break Air blast SF6 None Hint36). Which of the following is the example of oil circuit breaker? Bulk oil CB Low oil CB Air blast Both a and b None Hint37). Which of the following are the examples of oil less type CB? Air break Air blast SF6 All the above None Hint38). Which of the following is the example of DC based circuit breaker? HDVC Oil circuit breaker Oil-less circuit breaker Both a and b None Hint39). ___ is the medium type in an air type circuit breaker? Quenching Oil Gas All the above None Hint40). Which is the voltage level of air type circuit breaker? 15KV 10KV 20KV 25KV None Hint41). Which of the following are air type circuit breakers? Plain air based circuit breaker Air blast based circuit breaker Axial blast circuit breaker All the above None Hint42). Which of the following type of circuit breaker operates at a voltage of 245kV? Plain air based circuit breaker Air blast based circuit breaker Axial blast circuit breaker Both b and c None Hint43). Which is the other name for plain type air circuit breaker? Cross blast based circuit breaker Bent circuit breaker Bow circuit breaker Both a and c None Hint44). Which are the components of plain air based circuit breakers? Chamber Contacts Arc chute All the above None Hint45). Which component of plain air type CB drives the device? Chamber Contacts Arc chute All the above None Hint46). Which of the following are the components of arc chute circuit breaker? Compartments Metallic separations Splitters All the above None Hint47). The arc voltages generated in plain air circuit breaker is _____ than system based voltage? Higher Lower Zero Equal None Hint48). Plain air type circuit breaker is compatible only for ___ type of applications? Low voltage High voltage Low resistance High resistance None Hint49). Which are the components of air blast type circuit breaker? Piston Closing spring Isolator All the above None Hint50). Which of the following are the advantages of air based blast circuit breaker? Risk free Quenching of arch is speed Low maintenance All the above None HintCircuit Breaker Questions for Interviews51). Which of the following are the disadvantages of air blast type circuit breaker? Greater capacity air compressor Air leakage More maintenance in critical condition All the above None Hint52). Which of the following are the applications of air circuit breaker? Plant protection Power sharing High current applications All the above None Hint53). In SF6 circuit breaker what does SF stands for? Sulfur hexafluoride Silicon Hexafluoride Salt Hexafluoride Sulfur hydrogen None Hint54). Which of the following is the property of SF6 CB? Insulating Electro negativity Greater affinity All the above None Hint55). Which of the following is the equation of SF6 Circuit breaker? SF6 + e = SF6 SF6 + e = SF5- + F SF6 - e = SF5- + F Both a and b None Hint56). ____ components are heavier in SF6 based circuit breaker? Negative ions Free electrons Protons Neutrons None Hint57). The particles which are energized and moved results in _____current via gas? Conducting Non-conducting Insulating Both b and c None Hint58). SF6 based circuit breaker is deployed in ____ type of voltage based electrical power systems? High Low Medium Both a and c None Hint59). Which is the voltage range of SF6 based circuit breaker? 33KV to 800KV -33KV to 800KV 313KV to 800KV 33KV to 890KV None Hint60). SF6 is _____ times efficient than arc quenching based media? 50 90 99 100 None Hint61). Which of the following type of SF6 circuit breaker operates on application up to 220 V? Single Interrupter Two interrupter Four interrupter Five interrupter None Hint62). Which of the following type of SF6 circuit breaker operates on application up to 400 V? Single Interrupt Two interrupter Four interrupter Five interrupter None Hint63). Which of the following type of SF6 circuit breaker operates on application up to 715 V? Single Interrupter Two interrupter Four interrupter Five interrupter None Hint64). Vacuum in a vacuum based circuit breaker _____ the arc? Terminates Extincts Clamps Clips None Hint65). Which of the following property is excellent in vacuum based CB? Electric Conductivity Dielectric All the above None HintRead more about Dielectric Materials66). Which of the following are the characteristics of Vacuum based circuit breaker? Good interruption Stabilizes the circuit Dielectric based recovery All the above None Hint67). Which of the following are the components of vacuum circuit breaker? Electrodes Arc shield Insulating vessel All the above None Hint68). What is the arc value generated in vacuum based circuit breaker? 10^-7 to 10^-5 Torr 10^7 to 10^-5 Torr 10^-7 to 10^5 Torr 10^7 to 10^5 Torr None Hint69). During arc extinguished process in vacuum based circuit breaker _____ is generated? Electrons Metallic vapor Ions All the above None Hint70). Which of the following are the advantages of Vacuum based circuit breakers? Reliable Zero fire hazard Zero noise All the above None Hint71). Which gas form is decomposed in a oil based circuit breaker? Nitrogen Hydrogen Oxygen All the above None Hint72). Which of the following are the types of oil based circuit breaker? Bulk oil Minimum oil Maximum oil Both a and b None Hint73). Which of the following are the advantages of bulk oil based circuit breakers? Excellent decomposition Greater dielectric strength Absorption of arc energy All the above None Hint74). Which of the following are the disadvantages of bulk oil based circuit breakers? Limits high speed based interruption Long arcing based time High noise Both a and b None Hint75). Which of the following are the advantages of minimum oil based circuit breaker? Low maintenance Auto and manual operation Occupies less space All the above None HintCircuit Breaker MCQs for Exams76). Which of the following are the disadvantages of minimum oil based circuit breaker? Carbonization Explosion of device Difficult to remove gas between spaces All the above None Hint77).Which of the following are the types of voltage based circuit breakers? High voltage Low voltage Medium voltage Both a and b None Hint78). Which of the following is high voltage based circuit breaker voltage value? >1000V 200V 300V 400V None Hint79). Which of the following is the subclass of high voltage based CB? 75kV 123kV 150kV Both a and b None Hint80). Which of the following is low voltage based circuit breaker voltage value? <1000V 200V 300V 400V None Hint81). Which is the class of installation based CB? Enclosed air Open air Short Both a and b None Hint82). ___ is the voltage level of operation of installation based CB? High Low Medium Zero None Hint83). Which of the following are application of enclosed based CB? Internal building Weather impervious compounds Holding equipment Both a and b None Hint84). Which of the following is the external based design CB? Dead tank Live tank Near tank Both a and b None Hint85). At____ potential in a dead tank based CB the switching equipment is placed? Base Maximum Minimum Zero None Hint86). At____ potential in a live tank based CB the switching equipment is placed? Base Maximum Minimum Zero None Hint87). Which of the following are the enclosed substances of dead tank CB? Shielding medium Interrupters Tires Both a and b None Hint88). ___ is a switching device type CB? Oil Air Bulk oil HVDC None Hint89). ___ happens in HVDC when there is a damage? Isolates mechanical contacts Breaks the devices Explodes All the above None Hint90). Which of the following are the components of HVDC circuit? Inductor Circuit breaker Switch All the above None HintRead more about Inductor91). ___ is zero in HVDC based CB? Power dissipation Resistance Reactance Capacitance None Hint92). Which of the following are the issues observed in HVDC CB? Obstruction of arc based re-striking In-temperance based stored energy Produces artificial based null current All the above None Hint93). ____ CB observe device functionality to operate? Standard CB Live tank CB HVDC CB Oil CB None Hint94). Which are the types of Standard based CB? Single pole based Double pole based Multi pole Both a and b None Hint95). Which are the features of single pole based CB? Household appliances Safeguards via one energized wire Capacity of 15 to 30 amps All the above None Hint96). Which of the following are the double pole based CB features? Operates up to 120V/ 240V 15amps to 30 amps current Heaters All the above None Hint97). Which of the following are the protective relay characteristics? Over current Reverse power Under frequency All the above None Hint98). Which of the following is the units of resistance? Ohms Farads Watts Henrys None HintRead more about Electrical Resistance99). Which of the following is the names of circuit breaker? Fuse OCPD Switch All the above None Hint100). Abbreviate OCPD of CB? Over current protection Device Over circuit protection device Out current protection Device All the above None Hint Time's up
