Isolator Question & Answers February 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 Hint 2). Where we can find Isolators? Electrical Distribution Industries House All Mentioned Above Hint 3). What is used in electrical substations to provide isolation? Connector Disconnector Clamper Adapter Hint 4). Which switch is used to isolate the devices for safety purposes? Connector Disconnector Clamper Adapter Hint 5) Electric arc suppression is absent in ___________? Connector Disconnector Clamper Adapter Hint 6). Breaking capacity is low in __________? Connector Disconnector Clamper Adapter Hint 7). IEC 62271-102 is the standard of ___________? Connector Disconnector Clamper Adapter Hint 8). Lockout-tagout is possible in ____________? Connector Disconnector Clamper Adapter Hint 9). Greater voltage with-standing capability must be in ____________? Connector Disconnector Clamper Adapter Hint 10). How the isolators are operated? Automatic Manual Programming a & b Hint 11). When does an isolator can open the circuit? During Load No Load Adding Loads Removing Loads Hint 12). What is placed at the circuit breaker ends? Connector Disconnector Clamper Adapter Hint 13). How do the isolators are classified? Based on System Requirement Based on Power System Position Based on Circuit Current a & b Hint 14). Which isolator belongs to the category of system requirements? Pantograph Transfer Bus Side Line Side Bus Side Hint 15). What are the various isolators based on the requirement of the system? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 16). In how many types the isolators are classified based on the location of power systems? Four Three Two None Hint 17). Which Isolator has a connection with the Main bus? Pantograph Transfer Bus Side Line Side Bus Side Hint 18). Which isolators are present at the feeders? Pantograph Transfer Bus Side Line Side Bus Side Hint 19). Which Isolator has a connection with the Transfer bus? Pantograph Transfer Bus Side Line Side Bus Side Hint 20). How many stacks of post insulators are present in Double-break isolators? Four Three Two None Hint 21). Isolators are __________? Uni-line Double-line Triple-line Multiple-line Hint 22). The non-conductive separations that inhibit the flow of current occur in _______? Connector Disconnector Clamper Adapter Hint 23). What blocks the high common-mode voltages in the signals? Connector Disconnector Clamper Adapter Hint 24). What can block the voltage potential? Connector Disconnector Clamper Adapter Hint 25). What is the necessity of using Electrical isolation? Block Hazardous Voltages Transfer Break Ground Loops Allow Voltage Transfer a & b Hint Isolator MCQs for Interviews 26). How Galvanic Isolation can be accomplished? Addition of Distance Clearance Insulating Material All Mentioned Above Hint 27). How the isolation can be performed on signals? Physical Separation Insulating Material Conducting Material a & b Hint 28). What is the example of a Galvanic Isolator? Resistor Capacitor Inductor Transformer Hint 29). What is bulkier than the capacitive isolators? Resistor Capacitor Inductor Transformer Hint 30). What prevents the circuit from electric shocks? Four Three Two None Hint 31). Galvanic isolators block _______________? Low Voltage DC Current High Voltage DC Current Zero Voltage AC Current High Voltage AC Current Hint 32). What is allowed to pass through Galvanic isolators? AC Fault Currents High Voltage DC Current Zero Voltage AC Current High Voltage AC Current Hint 33). How many terminals are used for connection & disconnection in single break isolators? Four Three Two One Hint 34). Which isolator has a movable terminal at the center? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 35). No mechanism of locking in ____________? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 36). What is used on the circuit breaker on both sides? Connector Disconnector Clamper Adapter Hint 37). What is connected between the line & feeder? Connector Disconnector Clamper Adapter Hint 38). What is used if the main bus-side isolators are not available? Pantograph Transfer Bus Side Line Side Bus Side Hint 39). Which isolators are used in circuit breakers? Transfer Bus Side Line Side Bus Side a & c Hint 40). What are the isolators based on the voltage of the line? Low Voltage Isolators High Voltage Isolators Medium Voltage Isolators All Mentioned Above Hint 41). Which isolator can withstand 11kV voltages? Low Voltage Isolators High Voltage Isolators Medium Voltage Isolators All Mentioned Above Hint 42). Medium Voltage isolators can withstand __________? 11 kV 11kV-66kV 66kV-330kV 330kV Hint 43). How many loads of post-insulators are present in Double Break Isolators? Four Three Two None Hint 44). 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 Hint 45). In how many parts the arm contacts in Single Break Isolators are divided? Four Three Two None Hint 46). What do the arms of the Single Break Isolator contain? Male Contact Female Contact No Contact a & b Hint 47). Which isolator does not require more space? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 48). Which isolator is used in switchgear installation? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 49). Insulation medium is not required by ___________? Connector Disconnector Clamper Adapter Hint 50). Trap charges are easier to eliminate in __________? Connector Disconnector Clamper Adapter Hint Isolator MCQs for Students 51). The main & moving both contacts are present in ___________? Connector Disconnector Clamper Adapter Hint 52). Which of these devices does not require a Current rating? Relay Circuit Breaker Load Break Switch Isolator Hint 53). When does an isolator provide isolation to supplied power? Inspection Maintenance Repair All Mentioned Above Hint 54). What removes the charges trapped? Relay Circuit Breaker Load Break Switch Isolator Hint 55). Relay system is not required in ____________? MCB Circuit Breaker Load Break Switch Isolator Hint 56). During switching overvoltage is not rise in __________? Relay Circuit Breaker Load Break Switch Isolator Hint 57). Which type of switches of isolation are used in substations? Low Voltage High Voltage Medium Voltage Zero Voltage Hint 58). 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 Hint 59). What contains the Earth switch? Connector Disconnector Clamper Adapter Hint 60). Isolators are __________? Costly Cheap Higher Cost Increased Cost Hint 61). How many poles of isolators are available? Four Three Two All Mentioned Above Hint 62). Turning ON or OFF the isolators is _________? Automatic Manual Both a & b Programmed Hint 63). Isolator’s function if the current flowing through the device is _______? Infinite 10 A Finite Zero Hint 64). What ensures the max. safety while maintaining the circuit? Connector Disconnector Clamper Adapter Hint 65). Overload protection is not possible in ___________? Circuit Breakers Isolators MCBs Adapters Hint 66). Which devices cannot break loads? Circuit Breakers Isolators MCBs Adapters Hint 67). Which is operated after circuit breakers? Loads Isolators MCBs Adapters Hint 68). For manual usage what should be the limited voltage for isolators? 100 kV 125 kV 145 kV 245 kV Hint 69). What happens to the capacity of breaking in isolators? High Less More Severe Hint 70). ___________ lacks the inbuilt ‘arc suppressing system’? Circuit Breakers Isolators MCBs Adapters Hint 71). What requires maintenance frequently? Circuit Breakers Isolators MCBs Adapters Hint 72). Industrial sectors mostly use ______? Circuit Breakers Isolators MCBs Adapters Hint 73). Why there are low withstanding capacities in isolators? On-Load Off-Load No Load a & b Hint 74). The poles used in isolators are __________? High Less Low No Poles Hint 75). Which isolator is used to provide connectivity among the busbars? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint Isolator MCQs for Exams 76). Pantograph isolators are __________? Single Break Double break Vertical Type a & c Hint 77). ____________ have a dead mechanism at the center? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 78). Which isolator was installed that minimize the area of the substation? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 79). What is the medium utilized by Isolator? Vacuum Air SF6 Gas Other Gases Hint 80). What can be disconnected using Isolators? Bus Bars Circuit Breakers Transformers All Mentioned Above Hint 81). Insertion loss should be least in ___________ of the microwave? Connector Disconnector Clamper Adapter Hint 82). What allows the constant impedances at the transmitter? Connector Disconnector Clamper Adapter Hint 83). What minimizes the interferences between the incident & reflected wave? Connector Disconnector Clamper Adapter Hint 84). What permits microwave power to transmit in a single direction? Connector Disconnector Clamper Adapter Hint 85). Electrical Isolators provide _______________? Signal Combination Signal Isolation Signal Transmission Signal Allocation Hint 86). Which isolators are used in Electrical trains? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 87). Isolator must be ______as the circuit breakers in a circuit will be open? Open Close Neither a nor b Can’t Say Hint 88). At which conditions do isolators operate? No Load Full Load Severe Load Medium Load Hint 89). Electrical substations use ________ switch to disconnect power transformers. Circuit Breakers Isolators MCBs Adapters Hint 90). Isolators are used in ___________? Main Power Switch Local Control Switch Fuse Alternative Protective Circuit Hint 91). Where we can find Electrical isolators? Transformers Transmission Lines Grids All Mentioned Above Hint 92). Which isolators are abundantly used in the substations? Pantograph Type Isolators Single Break Isolators Double Break Isolators All Mentioned Above Hint 93). Isolators are utilized in ____________? Low Voltage Devices High Voltage Devices Medium Voltage Devices All Mentioned Above Hint 94). What are the important elements of an Isolator? Insulation Material Structure Data Transfer Method All Mentioned Above Hint 95). What is the downside of Isolators? Cleaning is Difficult Internal Surface Sanitising is Difficult Cleaning Become Easier a & b Hint 96). The isolator matrix will not be __________? Asymmetric Unitary Symmetric Lossless Hint 97). The power reflecting from the source will be absorbed __________? Connector Isolator Clamper Adapter Hint 98). Dc signals are blocked by __________? Connector Isolator Clamper Adapter Hint 99). Which can be operated manually? Connector Isolator Clamper Adapter Hint 100). What separates the sub-station fault section? Connector Isolator Clamper Adapter Hint Read More about Isolator Time's up
