Vacuum Circuit Breaker Question & Answers May 3, 2023 By Wat Electrical This article lists 100 Vacuum Circuit Breaker MCQs for engineering students. All the Vacuum 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 Vacuum Circuit Breaker. A circuit breaker interrupts an electric-based circuit to avert excess current. They are classified based on the type of insulation used such as air CB, vacuum CB, etc, and system rating criteria. The purpose of a vacuum-based CB is to safeguard the electric device from a breakdown in case of heavy current flow in the circuit, or heavily loaded added to the circuit and arc fault. The components of vacuum CB include a fixed member, movable member, arc shield, bellows, and insulating vessel. In a vacuum-based circuit breaker vacuum is used as an insulator. The properties of a vacuum circuit breaker include dielectric recovery, interruption of high frequency, and arc instability. The advantages of a vacuum-based circuit breaker include zero noise, zero fire hazard, and low power control. They are deployed in industrial networks, medium voltage power distribution, and switching loads. 1). A circuit breaker interrupts ______ to avert from excess current? Electric circuit Magnetic circuit Electo-magnetic circuit All the above None Hint 2). ____ is the condition for unwanted current in the circuit? Overload Half load Semi load Both b and c None Hint 3). Based on which criteria does a circuit breaker is designed? System rating Power consumption Load All the above None Hint 4). A circuit breaker is a type of device? Switching Resistor Breakdown Fuse None Hint 5). Which of the following are the primary types of circuit breakers? AC DC ADC Both a and b None Hint 6). Which of the following are DC based circuit breaker? HVDC High voltage CB Low voltage CB Oil Circuit Breaker None Hint 7). Which of the following are AC based circuit breaker? High voltage CB Low voltage CB Oil Circuit Breaker All the above None Hint 8). Which of the following are examples of high voltage circuit breakers? Oil Circuit breaker Air circuit breaker Oil Less Circuit Breaker Both a and c None Hint 9). Which of the following are the types of oil based circuit breaker? Bulk oil circuit breaker Low oil circuit breaker Air based circuit breaker Both a and b None Hint 10). The purpose of vacuum in a vacuum based CB is ____ the arc? Extinct Expel Break Close None Hint 11). Which of the following are the properties of vacuum circuit breaker? Dielectric recovery Interruption of high frequency Arc instability All the above None Hint 12). The 2 contacts in a vacuum based CB are ____ during in normal operating condition? Closed Open Shorted Both a and b None Hint 13). Which of the following are the components of vacuum CB? Fixed member Movable member Arch shield All the above None Hint 14). Which of the following component in vacuum CB is energized when contacts are separated? Trip coil Insulating vessels Arc shield All the above None Hint 15). Which is the reason for extinguishing of arc in vacuum circuit breaker? Production of electrons Production of metallic vapors Production of ions All the above None Hint 16). Which of the following are the types of SF6 based circuit breaker? Single interrupter Two interrupter Four interrupter All the above None Hint 17). Which of the following are advantages of vacuum based circuit breaker? Zero noise Zero fire hazard Low power control All the above None Hint 18). Which of the following are the properties of contact substances in a vacuum based CB? Greater density Less contact resistance Low Chopping level All the above None Hint 19). Which of the following substance is used in vacuum CB chamber? Steel Carbon Aluminum Cobalt None Hint 20). _____ quantity of vapour pressure decreases the metal vapour with in chamber of a Vacuum CB? High Low Medium Zero None Hint 21). _____ should be maintained less for greater longitivity of a vacuum CB? Gas quantity Vapour Boiling point Both a and b None Hint 22). Which of the following substances are used while designing Vacuum circuit breaker contacts? Copper - Bismuth Copper - Chrome Copper Both a and b None Hint 23). The moving contact within vacuum based is integrated with control mechanism using? Stainless steel bellow Iron bellow Cobalt bellow All the above None Hint 24). ___ avoids leakage within vacuum CB ? Permanent sealing Covering with ceramic substance Covering with glass All the above None Hint 25). Which of the following is the abnormal conditions where Vacuum CB contacts are separated? Arc struck Ionization Material contacts All the above None Hint Vacuum Circuit Breaker MCQ for Exams 26). ____ is different in vacuum CB compared to other CB? Arc interruption Design Control Resistance None Hint 27). Vapour density in vacuum based CB is _______ when current decreases? Decreases Increases Zero Constant None Hint 28). The arc in vacuum based CB is ____ when small amount of current is interrupted? Parallel paths Serial paths Hybrid paths None Hint 29). When current is high in vacuum based circuit breaker then the arc is concentrated in ____ quantity region? Small Large Medium No region None Hint 30). ___ influences the chopping levels in a vacuum based CB? Thermal conductivity Electron emission Instability High current None Hint 31). The insulating substance of a vacuum based CB is used for extinction _____ type of arc? High Low Medium Zero None Hint 32).Which of the following is the extraordinary property of vacuum based circuit breaker? Superior dielectric medium Increase in strength when circuit breaker is opened Superior conducting medium Both a and b None Hint Read more about Dielectric materials 33). A condition where vacuum CB operates with maximum efficiency? Maximum Minimum Constant Zero None Hint 34). ___ is the pressure value in a vacuum based circuit breaker? 10 ^-4 10^-5 10^-6 10^-8 None Hint 35). A vacuum based circuit breaker is not superior than ___ type of circuit breakers? SF6 Air Water Both a and b None Hint 36). The extraordinary properties of vacuum based CB provides _______ ? Proficient operation Minimum weight Less cost All the above None Hint 37). Which of the following are the interfaced components of a vacuum based circuit breaker? Interrupter Terminals Support insulators All the above None Hint 39). Design of vacuum based circuit breaker is classified based on? Manufacturing Deploying Non-deploying All the above None Hint 40). Which of the following are the types of vacuum based circuit breakers? Mitsubishi Siemens Capacitive Both a and b None Hint 41). Which of the following are the features of Mitsubhi based vacuum circuit breaker? Wide product lineup range Labeling of materials Easy maintenance All the above None Hint 42). Which of the following are the advantages of Mistsubishi based vacuum circuit breaker? Greater safety Reliability Protection All the above None Hint 43). Which of the following is siemens based circuit breaker? SION 3AE5 SON 2AE5 SIN 2AE8 Both b and c None Hint 44). Which of the following is the application of siemens based vacuum CB? Industrial networks Medium voltage power distribution Switching load All the above None Hint 45). Which of the following is the advantage of solid structure of a siemens based CB? Least depth Width dimension Minimizes panels usage All the above None Hint 46). Which of the following is the main feature of siemen based CB? Compact in design High reliability Greater service life All the above None Hint 47). Testing of vacuum circuit breaker test _____? Performance Overall tripping system Substances Both a and b None Hint 48). Which of the following are the types of test performed on vacuum based CB? Contact resistance High potential withstand Leak rate test All the above None Hint 49). Which of the following are the errors observed in a vacuum based circuit breaker? Earth fault Short circuit Under voltage All the above None Hint 50). Endurance of a Vacuum CB is _____? High Low Zero Medium None Hint Vacuum Circuit Breaker MCQ for Interviews 51). In vacuum CB the endurance value is ___ for mechanical? High Low Medium Zero None Hint 52). ___ are used as protective components in vacuum based circuit breaker? Relays Fuses Load Both a and b None Hint 53). Which of the following is the medium voltage value of vacuum based circuit breaker? 11kV to 3kV 12kV to 4kV 20kV to 100kV None Hint 54). Which of the following media does not suits vacuum based circuit breaker? Air Water SF6 Both a and c None Hint 55). __ are classification of vacuum based circuit breakers constructions? Fixed Moving Arc shield All the above None Hint 56). When silver based mirror is formed on the glass covering the vacuum circuit then it indicates? Device loosing vacuum Device gaining vacuum Device breakdown Both b and c None Hint 57). Presence of fault in vacuum based circuit breaker ___ the contacts? Separates Merges Collides All the above None Hint 58). Due to ____ property vapour is filled in vacuum based CB? Ionization Condensation Evaporation Both b and c None Hint 59). Pulling the contacts away in a vacuum based CB ____ the temperature value? Increases Decreases Zero Constant None Hint 60). The vapour density in vacuum base CB relies on ____? Arcing current Non arcing current Gaseous current All the above None Hint 61). Interruption of current is ___ when there are several arc paths? Small Large Medium Zero None Hint 62). A circuit breaker is ____ type of device? Electrical Electronic Mechanical Both a and b None Hint 63). ___ is the condition that defines an electric circuit has larger current? Over current Under current Zero current Both b and c None Hint 64). ___ protects circuits wiring from electric damage? Fuses Relays Circuit breaker All the above None Hint Read more about Overload Relays 65). Which of the following are the reasons for over current? Short circuit Excessive load arc fault All the above None Hint 66). A fuse is a ___ type of device? Electronic Electrical Mechanical Both a and b None Hint 67). A fuse is a ___ type of component? Passive Active Both a and b Non-passive None Hint 68). A fuse is a _____ type of operating device? Automatic Manual Passive Both b and c None Hint 69). A fuse comprises of ___ elements? Metal strip Wire fuse Non-combustible housing All the above None Hint 70). __ substances are used for developing fuse elements? Zinc Copper Silver All the above None Hint 71). Which of the following are the characteristics of a fuse? Rated current Time vs current characteristics I2t value All the above None Hint 72). A CB in small devices protect ____? Low current based circuits Household based appliances Individual appliances All the above None Hint 73). Low voltage based circuit breakers use ___ as insulating medium? Water Air Oil Gas None Hint 74). Abbreviate MCB? Miniature circuit breaker Maxima circuit breaker Mint circuit breaker All the above None Hint 75). A miniature based CB comprises of ___components? Arc chutes Metal plates Magnetic coil All the above None Hint Vacuum Circuit Breaker for Students 76). A magnetic based blowout coils in a miniature based circuit breaker is also called? Permanent magnet Non-permanent magnet Ferro magnet All the above None Hint 77). Which of the following is used as major substance in a gas based circuit breaker? Sulfur hexafluoride Sulfur bi-carbonate Sulfur dioxide Both b and c None Hint 78). Sulfur hexafluoride substance is used in ____ type of rating circuit? Higher Lower Medium Zero None Hint 79). Air based circuit breakers use ____ to remove the arc? compressed air Compressed water High current input All the above None Hint 80). Circuit breakers are rated via ____ ? Normal current Short circuit current Open circuit current Both a and b None Hint 81). Which property differs in short and normal circuit conditions? Max Prospective current Min prospective current Zero prospective current Both b and c None Hint 82). Electric arc is also called? Arc discharge Arc charge Bi-charge Di-charge None Hint 83). Arc discharge is generated via _____? Thermionic emission Field emission Light incident Both a and b None Hint 84). ___ is produced when current passes though air in a circuit breaker? Light Water Gas Liquid None Hint 85). Arc suppression methods is deployed for ___ purpose? Minimize arc suppression duration Maximize arc suppression duration Minimize likelihood of arc formation Both a and c None Hint 86). Which of the following are the applications of electric arcs in manufacturing process? Electric arc welding Electric arc furnance Steel recycling All the above None Hint 87). Which of the following are the applications of electric? Welding plasma cutting Arc lamp Movie projectors All the above None Hint 88). ___ is defined as the electric discharge with high current density? Electric arc Electric power Electric resistance Electric capacitance None Hint 89). A drawn arc in a electric arc is aroused due to ____ component? Electrodes Wire Vacuum Air None Hint 90). Which of the following is the voltage value that a air based circuit breaker handles? 1000V Less than 1000V 2000V 3000V None Hint 91). Which of the following are the classification of circuit breakers? Air circuit breaker Two pole based miniature circuit breaker Four one based miniature circuit breaker All the above None Hint 92). _____ connects multiple generators source through electric grid? Circuit breaker Switch Capacitor Resistor None Hint 93). A device which connects multiple heavy electric substance to protect from breakdown. AC DC ADC DAC None Hint 94). Impedance is represented via combination of? Resistance Reactance Capacitance Both a and b None Hint 95). ___ is the reciprocal of impedance? Admittance Reactance Capacitance Inductance None Hint 96). Admittance is ___ quantity? Scalar Vector Non-scalar Both a and c None Hint 97). Which of the following are the SI units of admittance? Siemens Ohms Farads Meters None Hint 98). ___ is device used to measure electric impedance? Analyzers Oscillators Multimeters All the above None Hint 99). ____ type of circuit breaker are examples of low voltage CB? Miniature CB Molded case CB Low voltage power CB All the above None Hint 100). Which of the following is the current value of molded based case circuit breaker? 1600A 1200A 3000 A 1405A None Hint For More MCQs Oil Circuit Breaker Question & Answers. SF6 Circuit Breaker Question & Answers. Circuit Breaker Question & Answers. Time's up
