Isolator Question & AnswersFebruary 16, 2023 By Wat Electrical This article lists 100 Isolator MCQs for engineering students. All the Isolator 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, or interviews, or professionals who would like to brush up on the fundamentals of Isolator.A switch that is operated manually and can isolate the sub-station fault section is referred to as an Isolator. It is also known as a Disconnector. Two distinct parts of the power circuits or the instruments are isolated using Isolators. The separation of parts can be either electrical or physical and sometimes can be both. When it is no load in the circuit it can be opened using electrical switches called Isolators. These circuits should not be opened when there is a flowing current detected in the circuit. These Isolators are installed at the ends of Circuit breakers such that they can be repaired without risks.Depending on applications isolators are categorized as Double break, single break & Pantograph. Based on the location of power systems these isolators are classified into three distinct types. They are Bus side, Line side & Transfer bus-side isolators.There is a major difference between the circuit breaker & isolator. The circuit is detached during Off-load conditions in isolators whereas it is isolated for ON-load conditions in circuit breakers. But both follow the similar detachment principle. Isolators are used in the transmission lines to insulate them from conductors. 1). What is an Isolator? Connector Disconnector Clamper Adapter None Hint2). Where we can find Isolators? Electrical Distribution Industries House All Mentioned Above None Hint3). What is used in electrical substations to provide isolation? Connector Disconnector Clamper Adapter None Hint4). Which switch is used to isolate the devices for safety purposes? Connector Disconnector Clamper Adapter None Hint5) Electric arc suppression is absent in ___________? Connector Disconnector Clamper Adapter None Hint6). Breaking capacity is low in __________? Connector Disconnector Clamper Adapter None Hint7). IEC 62271-102 is the standard of ___________? Connector Disconnector Clamper Adapter None Hint8). Lockout-tagout is possible in ____________? Connector Disconnector Clamper Adapter None Hint9). Greater voltage with-standing capability must be in ____________? Connector Disconnector Clamper Adapter None Hint10). How the isolators are operated? Automatic Manual Programming a & b None Hint11). When does an isolator can open the circuit? During Load No Load Adding Loads Removing Loads None Hint12). What is placed at the circuit breaker ends? Connector Disconnector Clamper Adapter None Hint13). How do the isolators are classified? Based on System Requirement Based on Power System Position Based on Circuit Current a & b None Hint14). Which isolator belongs to the category of system requirements? Pantograph Transfer Bus Side Line Side Bus Side None Hint15). What are the various isolators based on the requirement of the system? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint16). In how many types the isolators are classified based on the location of power systems? Four Three Two None None Hint17). Which Isolator has a connection with the Main bus? Pantograph Transfer Bus Side Line Side Bus Side None Hint18). Which isolators are present at the feeders? Pantograph Transfer Bus Side Line Side Bus Side None Hint19). Which Isolator has a connection with the Transfer bus? Pantograph Transfer Bus Side Line Side Bus Side None Hint20). How many stacks of post insulators are present in Double-break isolators? Four Three Two None None Hint21). Isolators are __________? Uni-line Double-line Triple-line Multiple-line None Hint22). The non-conductive separations that inhibit the flow of current occur in _______? Connector Disconnector Clamper Adapter None Hint23). What blocks the high common-mode voltages in the signals? Connector Disconnector Clamper Adapter None Hint24). What can block the voltage potential? Connector Disconnector Clamper Adapter None Hint25). What is the necessity of using Electrical isolation? Block Hazardous Voltages Transfer Break Ground Loops Allow Voltage Transfer a & b None HintIsolator MCQs for Interviews26). How Galvanic Isolation can be accomplished? Addition of Distance Clearance Insulating Material All Mentioned Above None Hint27). How the isolation can be performed on signals? Physical Separation Insulating Material Conducting Material a & b None Hint28). What is the example of a Galvanic Isolator? Resistor Capacitor Inductor Transformer None Hint29). What is bulkier than the capacitive isolators? Resistor Capacitor Inductor Transformer None Hint30). What prevents the circuit from electric shocks? Four Three Two None None Hint31). Galvanic isolators block _______________? Low Voltage DC Current High Voltage DC Current Zero Voltage AC Current High Voltage AC Current None Hint32). What is allowed to pass through Galvanic isolators? AC Fault Currents High Voltage DC Current Zero Voltage AC Current High Voltage AC Current None Hint33). How many terminals are used for connection & disconnection in single break isolators? Four Three Two One None Hint34). Which isolator has a movable terminal at the center? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint35). No mechanism of locking in ____________? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint36). What is used on the circuit breaker on both sides? Connector Disconnector Clamper Adapter None Hint37). What is connected between the line & feeder? Connector Disconnector Clamper Adapter None Hint38). What is used if the main bus-side isolators are not available? Pantograph Transfer Bus Side Line Side Bus Side None Hint39). Which isolators are used in circuit breakers? Transfer Bus Side Line Side Bus Side a & c None Hint40). What are the isolators based on the voltage of the line? Low Voltage Isolators High Voltage Isolators Medium Voltage Isolators All Mentioned Above None Hint41). Which isolator can withstand 11kV voltages? Low Voltage Isolators High Voltage Isolators Medium Voltage Isolators All Mentioned Above None Hint42). Medium Voltage isolators can withstand __________? 11 kV 11kV-66kV 66kV-330kV 330kV None Hint43). How many loads of post-insulators are present in Double Break Isolators? Four Three Two None None Hint44). When do Double Break Isolators get disconnected? Male Contact Rotating in Opposite Direction Male Contact Rotating in Same Direction Male Contact does not Rotate Male Contact is Constant None Hint45). In how many parts the arm contacts in Single Break Isolators are divided? Four Three Two None None Hint46). What do the arms of the Single Break Isolator contain? Male Contact Female Contact No Contact a & b None Hint47). Which isolator does not require more space? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint48). Which isolator is used in switchgear installation? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint49). Insulation medium is not required by ___________? Connector Disconnector Clamper Adapter None Hint50). Trap charges are easier to eliminate in __________? Connector Disconnector Clamper Adapter None HintIsolator MCQs for Students51). The main & moving both contacts are present in ___________? Connector Disconnector Clamper Adapter None Hint52). Which of these devices does not require a Current rating? Relay Circuit Breaker Load Break Switch Isolator None Hint53). When does an isolator provide isolation to supplied power? Inspection Maintenance Repair All Mentioned Above None Hint54). What removes the charges trapped? Relay Circuit Breaker Load Break Switch Isolator None Hint55). Relay system is not required in ____________? MCB Circuit Breaker Load Break Switch Isolator None Hint56). During switching overvoltage is not rise in __________? Relay Circuit Breaker Load Break Switch Isolator None Hint57). Which type of switches of isolation are used in substations? Low Voltage High Voltage Medium Voltage Zero Voltage None Hint58). The insulator's ability that minimizes the current flow for high voltages applied is referred to as ___________? Low Voltage Isolation Voltage Medium Voltage Zero Voltage None Hint59). What contains the Earth switch? Connector Disconnector Clamper Adapter None Hint60). Isolators are __________? Costly Cheap Higher Cost Increased Cost None Hint61). How many poles of isolators are available? Four Three Two All Mentioned Above None Hint62). Turning ON or OFF the isolators is _________? Automatic Manual Both a & b Programmed None Hint63). Isolator’s function if the current flowing through the device is _______? Infinite 10 A Finite Zero None Hint64). What ensures the max. safety while maintaining the circuit? Connector Disconnector Clamper Adapter None Hint65). Overload protection is not possible in ___________? Circuit Breakers Isolators MCBs Adapters None Hint66). Which devices cannot break loads? Circuit Breakers Isolators MCBs Adapters None Hint67). Which is operated after circuit breakers? Loads Isolators MCBs Adapters None Hint68). For manual usage what should be the limited voltage for isolators? 100 kV 125 kV 145 kV 245 kV None Hint69). What happens to the capacity of breaking in isolators? High Less More Severe None Hint70). ___________ lacks the inbuilt ‘arc suppressing system’? Circuit Breakers Isolators MCBs Adapters None Hint71). What requires maintenance frequently? Circuit Breakers Isolators MCBs Adapters None Hint72). Industrial sectors mostly use ______? Circuit Breakers Isolators MCBs Adapters None Hint73). Why there are low withstanding capacities in isolators? On-Load Off-Load No Load a & b None Hint74). The poles used in isolators are __________? High Less Low No Poles None Hint75). Which isolator is used to provide connectivity among the busbars? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None HintIsolator MCQs for Exams76). Pantograph isolators are __________? Single Break Double break Vertical Type a & c None Hint77). ____________ have a dead mechanism at the center? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint78). Which isolator was installed that minimize the area of the substation? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint79). What is the medium utilized by Isolator? Vacuum Air SF6 Gas Other Gases None Hint80). What can be disconnected using Isolators? Bus Bars Circuit Breakers Transformers All Mentioned Above None Hint81). Insertion loss should be least in ___________ of the microwave? Connector Disconnector Clamper Adapter None Hint82). What allows the constant impedances at the transmitter? Connector Disconnector Clamper Adapter None Hint83). What minimizes the interferences between the incident & reflected wave? Connector Disconnector Clamper Adapter None Hint84). What permits microwave power to transmit in a single direction? Connector Disconnector Clamper Adapter None Hint85). Electrical Isolators provide _______________? Signal Combination Signal Isolation Signal Transmission Signal Allocation None Hint86). Which isolators are used in Electrical trains? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint87). Isolator must be ______as the circuit breakers in a circuit will be open? Open Close Neither a nor b Can’t Say None Hint88). At which conditions do isolators operate? No Load Full Load Severe Load Medium Load None Hint89). Electrical substations use ________ switch to disconnect power transformers. Circuit Breakers Isolators MCBs Adapters None Hint90). Isolators are used in ___________? Main Power Switch Local Control Switch Fuse Alternative Protective Circuit None Hint91). Where we can find Electrical isolators? Transformers Transmission Lines Grids All Mentioned Above None Hint92). Which isolators are abundantly used in the substations? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above None Hint93). Isolators are utilized in ____________? Low Voltage Devices High Voltage Devices Medium Voltage Devices All Mentioned Above None Hint94). What are the important elements of an Isolator? Insulation Material Structure Data Transfer Method All Mentioned Above None Hint95). What is the downside of Isolators? Cleaning is Difficult Internal Surface Sanitising is Difficult Cleaning Become Easier a & b None Hint96). The isolator matrix will not be __________? Asymmetric Unitary Symmetric Lossless None Hint97). The power reflecting from the source will be absorbed __________? Connector Isolator Clamper Adapter None Hint98). Dc signals are blocked by __________? Connector Isolator Clamper Adapter None Hint99). Which can be operated manually? Connector Isolator Clamper Adapter None Hint100). What separates the sub-station fault section? Connector Isolator Clamper Adapter None HintRead More about Isolator Time's up
