Electrical Engineering MCQs (Part-49)

What is the primary purpose of lightning arresters in substations?

A To store electrical energy
B To protect equipment from voltage surges
C To regulate current flow
D To step down voltage levels

What is the function of a surge capacitor in substations?

A To increase reactive power
B To absorb transient surges
C To step up voltage
D To isolate faulty circuits

Which device is used to control the flow of power between two systems in a substation?

A Isolator
B Circuit breaker
C Power transformer
D Load break switch

What is the purpose of a double-busbar system in substations?

A To handle higher fault currents
B To provide operational flexibility and redundancy
C To store electrical energy
D To measure current levels

What is the purpose of a compact substation?

A A substation with no transformers
B A fully enclosed substation designed for limited spaces
C A substation with only renewable energy integration
D A temporary substation

Which type of relay is used for distance protection in transmission lines?

A Differential relay
B Distance relay
C Overcurrent relay
D Earth fault relay

What is the typical frequency of power systems in most countries?

A 50 Hz or 60 Hz
B 45 Hz
C 100 Hz
D 25 Hz

What is the role of a SCADA system in substations?

A To protect against lightning strikes
B To monitor and control substation operations remotely
C To step down voltage
D To increase power factor

Which test evaluates the dielectric strength of substation equipment?

A Power factor test
B High-voltage test
C Load test
D Relay test

What is the purpose of substation maintenance?

A To increase transmission losses
B To ensure equipment reliability and safety
C To improve energy consumption
D To disconnect loads

What does SCADA stand for?

A Supervisory Control and Data Access
B Supervisory Control and Data Acquisition
C Systematic Control and Data Automation
D Safety Control and Data Analysis

What is the primary function of SCADA in substations?

A To protect against overvoltage
B To monitor and control substation operations remotely
C To step down voltage levels
D To regulate frequency

What is the purpose of communication systems in substations?

A To improve grounding systems
B To ensure real-time data transfer and control
C To step up voltage levels
D To regulate reactive power

What is meant by power flow in an electrical network?

A The flow of current between two points
B The transfer of active and reactive power in a system
C The transmission of frequency
D The step-up of voltage levels

Which type of relay is used for fault management in transmission lines?

A Differential relay
B Distance relay
C Overcurrent relay
D Earth fault relay

What is insulation coordination in substations?

A The regulation of grounding systems
B The process of selecting the correct insulation for equipment based on voltage levels and surges
C The synchronization of breakers
D The management of current flow

Why are safety protocols important in substations?

A To improve efficiency
B To ensure the safety of personnel and equipment
C To reduce energy losses
D To step up voltage levels

What is reactive power control in substations?

A Managing active power in the system
B Regulating power used for electric and magnetic fields
C Controlling frequency
D Monitoring fault currents

What is the purpose of voltage control in a substation?

A To prevent frequency fluctuation
B To maintain system voltage within permissible limits
C To step up voltage levels
D To detect faults

What is substation automation?

A Manual control of substation equipment
B The integration of advanced digital technologies for remote operation and monitoring
C The reduction of reactive power in substations
D The storage of electrical energy

What is the role of energy storage integration in substations?

A To regulate current flow
B To store electrical energy for use during demand fluctuations
C To step up voltage levels
D To detect faults

Which device is essential for renewable energy interconnection in substations?

A Busbar
B Inverter
C Circuit breaker
D Lightning arrester

What is the purpose of fault management in substations?

A To increase current flow
B To detect, isolate, and clear faults in the system
C To reduce voltage levels
D To synchronize the grid

What is the function of intelligent electronic devices (IEDs) in substations?

A To store electrical energy
B To enhance automation and protection through data collection and control
C To step down voltage levels
D To measure insulation strength

Which device is used to improve power factor in substations?

A Circuit breaker
B Capacitor bank
C Relay
D Transformer

What is the role of voltage regulators in substations?

A To isolate faulty sections
B To automatically adjust voltage levels to maintain stability
C To store electrical energy
D To monitor fault currents

Which communication protocol is widely used in substation automation?

A Modbus
B IEC 61850
C HTTP
D Ethernet

What is a load flow study in power systems?

A The analysis of fault currents
B The study of active and reactive power distribution in a network
C The synchronization of breakers
D The design of insulation coordination

What is the purpose of backup protection in substations?

A To regulate voltage
B To operate when primary protection fails
C To control frequency
D To measure power flow

What is an earth fault relay used for?

A To monitor insulation strength
B To detect leakage currents to the ground
C To step down voltage levels
D To regulate reactive power

What is the main purpose of energy storage systems in substations?

A To reduce power losses
B To store electricity for peak demand or outages
C To regulate system frequency
D To step up voltage

Which type of communication system is essential for SCADA operations?

A Fiber optic communication
B Satellite communication
C Wireless LAN
D Bluetooth

What is the primary role of reactive power in electrical systems?

A To provide energy for lighting systems
B To maintain voltage levels and support power transfer
C To store energy for future use
D To isolate faulty circuits

What is the function of a load dispatch center in power systems?

A To step down voltage levels for distribution
B To monitor and control the generation and distribution of electricity
C To isolate faulty sections
D To test insulation coordination

Which protocol is used for real-time data exchange in substation automation?

A IEC 61850
B TCP/IP
C Modbus RTU
D HTTP

What does the term “fault current” mean in power systems?

A Normal operating current
B High current caused by a fault in the system
C Current used for reactive power control
D Backup current during outages

What is the role of substation automation in modern power systems?

A To eliminate manual operations entirely
B To enable remote monitoring, control, and fault diagnosis
C To improve insulation strength
D To store reactive power

What is the purpose of fault isolation in substations?

A To reduce power factor
B To separate faulted sections from the healthy system
C To step up voltage levels
D To store electrical energy

What is voltage regulation in a substation?

A The process of stabilizing system frequency
B The adjustment of voltage levels to maintain stability
C The reduction of reactive power
D The monitoring of current flow

What is the main purpose of insulation coordination in substations?

A To reduce current flow
B To ensure all equipment insulation can withstand expected voltage surges
C To step up voltage levels
D To improve grounding systems

Why are safety protocols important in substations?

A To improve efficiency
B To ensure the safety of personnel and equipment
C To reduce energy losses
D To step up voltage levels

What is the purpose of capacitor banks in substations?

A To step down voltage levels
B To provide reactive power and improve power factor
C To detect fault currents
D To monitor insulation coordination

What does “substation reliability” refer to?

A The ability of a substation to operate without maintenance
B The ability to maintain uninterrupted power supply with minimal faults
C The capability to step up voltage levels
D The integration of renewable energy sources

Which substation component manages the flow of power between two systems?

A Circuit breaker
B Power transformer
C Isolator
D Lightning arrester

What is a critical feature of renewable energy substations?

A Use of oil circuit breakers
B Integration of DC-to-AC inverters for grid compatibility
C Absence of grounding systems
D Exclusive use of overhead lines

What is the function of intelligent electronic devices (IEDs) in substations?

A To store electrical energy
B To enhance automation and protection through data collection and control
C To step down voltage levels
D To measure insulation strength

What is the role of substation automation in modern power systems?

A To eliminate manual operations entirely
B To enable remote monitoring, control, and fault diagnosis
C To improve insulation strength
D To store reactive power

What is the purpose of fault isolation in substations?

A To reduce power factor
B To separate faulted sections from the healthy system
C To step up voltage levels
D To store electrical energy

What is voltage regulation in a substation?

A The process of stabilizing system frequency
B The adjustment of voltage levels to maintain stability
C The reduction of reactive power
D The monitoring of current flow

What is the main purpose of insulation coordination in substations?

A To reduce current flow
B To ensure all equipment insulation can withstand expected voltage surges
C To step up voltage levels
D To improve grounding systems