Electrical Engineering MCQs (Part-51)

What is the purpose of a sectionalized busbar system?

A To divide the substation into separate voltage levels
B To enhance reliability by allowing sections to operate independently
C To reduce insulation requirements
D To eliminate the need for circuit breakers

What is the typical voltage range for a transmission substation?

A Below 33 kV
B 110 kV to 765 kV
C 11 kV to 33 kV
D Above 1000 kV

Which component protects substations from lightning surges?

A Lightning arrester
B Circuit breaker
C Capacitor bank
D Isolator

What is the role of tap changers in transformers?

A To regulate voltage levels
B To store electrical energy
C To step up current flow
D To detect faults

What does “substation reliability” ensure?

A That all faults are ignored
B That the system operates continuously with minimal outages
C That all equipment is replaced regularly
D That voltage levels are always stepped up

What is the primary purpose of a high-voltage circuit breaker?

A To step up voltage levels
B To interrupt large fault currents
C To measure current flow
D To store electrical energy

What is the typical voltage range for a transmission substation?

A Below 33 kV
B 110 kV to 765 kV
C 11 kV to 33 kV
D Above 1000 kV

Which component protects substations from lightning surges?

A Lightning arrester
B Circuit breaker
C Capacitor bank
D Isolator

What is the role of tap changers in transformers?

A To regulate voltage levels
B To store electrical energy
C To step up current flow
D To detect faults

What does “substation reliability” ensure?

A That all faults are ignored
B That the system operates continuously with minimal outages
C That all equipment is replaced regularly
D That voltage levels are always stepped up

What is the primary function of a transmission substation?

A To step up voltage for long-distance transmission
B To step down voltage for local distribution
C To store energy for peak demand
D To improve power factor

What is the typical purpose of a distribution substation?

A To transmit electricity across regions
B To step down voltage for residential and commercial use
C To regulate frequency
D To increase fault currents

Which substation component protects equipment from voltage surges caused by lightning?

A Circuit breaker
B Lightning arrester
C Transformer
D Capacitor bank

What is the purpose of substation maintenance?

A To store reactive power
B To ensure reliable operation and prevent equipment failure
C To reduce voltage levels
D To disconnect faulty circuits

What does “fault isolation” mean in a substation?

A Disconnecting faulted sections while maintaining power supply to healthy areas
B Disconnecting the entire system during a fault
C Increasing voltage levels during a fault
D Reducing reactive power during a fault

What is a sectionalized busbar system?

A A busbar that operates at high voltage
B A busbar divided into sections for reliability and flexibility
C A busbar designed for renewable energy substations
D A busbar with automatic grounding systems

What is the role of a relay in a substation?

A To regulate voltage levels
B To detect faults and signal circuit breakers
C To measure reactive power
D To step up current flow

What is the function of a capacitor bank in a substation?

A To step down voltage levels
B To provide reactive power and improve power factor
C To measure current flow
D To isolate faults

What is the purpose of routine maintenance in a substation?

A To step up voltage levels
B To prevent equipment failures and ensure smooth operation
C To monitor power flow
D To reduce insulation strength

What is the role of tap changers in transformers?

A To adjust transformer winding to regulate voltage
B To store electrical energy
C To step down current flow
D To provide reactive power

What is a dielectric strength test used for in substations?

A To measure current flow
B To determine the insulation’s ability to withstand high voltages
C To regulate voltage levels
D To improve power factor

What is the purpose of substation fault isolation?

A To disconnect faulty sections while maintaining power to healthy parts of the system
B To disconnect the entire system during a fault
C To increase power factor
D To store electrical energy

What is a power transformer used for in a transmission substation?

A To step up voltage levels for long-distance transmission
B To store electrical energy
C To measure power flow
D To isolate faulty sections

What is the main advantage of sectionalized busbars in substations?

A They reduce power losses significantly
B They allow parts of the busbar to operate independently, improving reliability
C They integrate renewable energy sources directly
D They eliminate the need for circuit breakers

What is the typical voltage range for high-voltage substations?

A Below 33 kV
B 110 kV to 765 kV
C 11 kV to 33 kV
D Above 1000 kV

What is the purpose of a high-voltage circuit breaker?

A To step up voltage levels
B To interrupt large fault currents
C To measure power flow
D To provide reactive power

What is the main advantage of compact substations?

A Lower cost
B Smaller size and suitability for urban areas
C Higher voltage handling capacity
D Easier maintenance

What is the function of a tap changer in transformers?

A To adjust transformer winding to regulate voltage
B To store electrical energy
C To step down current flow
D To provide reactive power

What is the typical voltage range for high-voltage substations?

A Below 33 kV
B 110 kV to 765 kV
C 11 kV to 33 kV
D Above 1000 kV

What is the role of an isolator in a substation?

A To interrupt fault currents
B To disconnect equipment for maintenance under no-load conditions
C To regulate voltage
D To store electrical energy

What is the primary purpose of substation layout design?

A To maximize power losses
B To optimize equipment placement and operational efficiency
C To reduce insulation costs
D To regulate current flow

Which component in a substation is used to step up or step down voltage levels?

A Relay
B Transformer
C Circuit breaker
D Lightning arrester

What is the main function of a circuit breaker in a substation?

A To regulate voltage levels
B To interrupt electrical flow during faults
C To store energy for peak demand
D To monitor power factor

What is the purpose of an isolator in a substation?

A To interrupt high fault currents
B To disconnect equipment during maintenance under no-load conditions
C To regulate voltage
D To measure insulation resistance

Which component distributes power to multiple circuits in a substation?

A Relay
B Busbar
C Capacitor bank
D Transformer

What is the role of relays in substation protection systems?

A To regulate current flow
B To detect faults and signal circuit breakers
C To provide reactive power
D To step down voltage levels

What is insulation coordination in substations?

A Matching insulation levels to expected voltage stresses
B Synchronizing circuit breakers
C Reducing reactive power in the system
D Increasing current flow during faults

What is the purpose of grounding systems in substations?

A To increase voltage levels
B To provide a safe path for fault currents to the ground
C To measure insulation resistance
D To improve power factor

Which device is used to protect substation equipment from voltage surges caused by lightning?

A Circuit breaker
B Lightning arrester
C Isolator
D Capacitor bank

What is the function of a capacitor bank in a substation?

A To step up voltage levels
B To provide reactive power and stabilize voltage
C To detect faults
D To disconnect faulty sections

What is SCADA in a substation?

A A system for storing electrical energy
B A real-time system for monitoring, control, and data acquisition
C A device to regulate reactive power
D A protocol for managing circuit breakers

What is the purpose of fault isolation in a substation?

A To increase system voltage
B To disconnect faulted sections while keeping the rest of the system operational
C To improve insulation coordination
D To store reactive power

What is the purpose of an emergency shutdown system in a substation?

A To safely disconnect power in critical situations
B To safely disconnect power in critical situations
C To measure voltage fluctuations
D To regulate reactive power

What is the function of a relay in a substation?

A To regulate current flow
B To detect faults and signal circuit breakers
C To provide reactive power
D To step down voltage levels

What does “substation reliability” mean?

A The ability of a substation to operate continuously with minimal interruptions
B The ability of a substation to operate continuously with minimal interruptions
C The ability to step up voltage during faults
D The efficiency of grounding systems

What is the role of a high-voltage circuit breaker?

A To step down voltage levels
B To interrupt high fault currents safely
C To provide reactive power
D To regulate frequency

Which substation type is fully enclosed and suitable for urban areas?

A Transmission substation
B Compact substation
C High-voltage substation
D Renewable energy substation

What is the function of a tap changer in a transformer?

A To step down voltage levels
B To adjust transformer winding to regulate voltage
C To provide reactive power
D To interrupt fault currents

What is the purpose of an emergency shutdown system in a substation?

A To safely disconnect power in critical situations
B To safely disconnect power in critical situations
C To measure voltage fluctuations
D To regulate reactive power

What is the main advantage of compact substations?

A Lower cost of operation
B Smaller size and suitability for urban areas
C Higher voltage handling capability
D Increased reactive power