Q.1 Which of the following is NOT a type of renewable energy source?
Solar photovoltaic
Natural gas
Wind turbine
Hydropower
Explanation - Natural gas is a fossil fuel, not a renewable source like solar, wind, or hydro.
Correct answer is: Natural gas
Q.2 What does PV stand for in the context of renewable energy?
Photovoltaic
Power Voltage
Passive Voltage
Peak Value
Explanation - PV is short for Photovoltaic, referring to technology that converts sunlight directly into electricity.
Correct answer is: Photovoltaic
Q.3 Which device stores electrical energy for later use in a power system?
Transformer
Battery
Capacitor
Motor
Explanation - A battery chemically stores energy and can release it as electricity when needed.
Correct answer is: Battery
Q.4 What is a common benefit of integrating wind turbines into a smart grid?
Reduced noise pollution
Increased fuel consumption
Higher peak load
Reduced need for storage
Explanation - Wind turbines are relatively quiet compared to combustion generators, helping lower noise pollution.
Correct answer is: Reduced noise pollution
Q.5 Which communication protocol is commonly used in smart meter networks?
Wi‑Fi
Zigbee
Bluetooth
Ethernet
Explanation - Zigbee offers low power consumption and mesh networking suitable for smart meter deployments.
Correct answer is: Zigbee
Q.6 In a microgrid, what is the role of a ‘controller’?
Generate electricity
Store energy
Regulate power flow
Measure voltage
Explanation - The controller monitors and adjusts power flows to maintain stability within the microgrid.
Correct answer is: Regulate power flow
Q.7 Which of these is a major challenge when integrating solar PV into a bulk power system?
Solar panels produce constant output
Solar generation is intermittent
Solar energy is stored in the atmosphere
Solar panels require no maintenance
Explanation - Solar output varies with clouds, time of day, and seasons, creating variability in the grid.
Correct answer is: Solar generation is intermittent
Q.8 What does the term ‘DER’ stand for in grid terminology?
Distributed Energy Resources
Direct Energy Relay
Dynamic Electric Relay
Digital Energy Regulator
Explanation - DER refers to small-scale power sources located close to load, such as rooftop solar or small wind turbines.
Correct answer is: Distributed Energy Resources
Q.9 Which of the following best describes ‘demand response’?
Increasing demand during peak hours
Reducing demand when supply is low
Maintaining constant demand
Adding more generators
Explanation - Demand response programs shift or cut load during periods when supply is constrained, improving reliability.
Correct answer is: Reducing demand when supply is low
Q.10 Which type of storage is most suitable for long‑term seasonal energy storage?
Lithium‑ion batteries
Flywheel
Hydrogen
Supercapacitors
Explanation - Hydrogen can store large amounts of energy for months or seasons, unlike batteries that lose capacity over time.
Correct answer is: Hydrogen
Q.11 What is the main advantage of a HVDC (High‑Voltage Direct Current) link in renewable integration?
Higher transmission losses
Better voltage regulation
Lower costs for long distances
Higher maintenance
Explanation - HVDC lines reduce losses over long distances, making them ideal for connecting remote renewables to the grid.
Correct answer is: Lower costs for long distances
Q.12 Which renewable source is most affected by seasonal variations?
Wind power
Solar PV
Hydropower
Geothermal
Explanation - Wind speeds vary more significantly with seasons compared to solar irradiance or geothermal output.
Correct answer is: Wind power
Q.13 What is the purpose of a ‘phasor measurement unit (PMU)’ in smart grids?
Generate electricity
Measure voltage and frequency in real time
Control transformer tap settings
Store energy
Explanation - PMUs provide synchronized, high‑resolution measurements of power system parameters for stability analysis.
Correct answer is: Measure voltage and frequency in real time
Q.14 Which technology is commonly used to convert DC power from solar panels to AC for the grid?
Rectifier
Inverter
Conductor
Capacitor
Explanation - An inverter converts DC output from PV modules into AC compatible with the utility grid.
Correct answer is: Inverter
Q.15 A wind turbine’s power output is proportional to which power of the wind speed?
1st power
2nd power
3rd power
4th power
Explanation - Power extracted from wind scales with the cube of wind speed, making small speed changes significant.
Correct answer is: 3rd power
Q.16 Which of the following is NOT a typical component of a battery management system (BMS)?
Cell balancing
Thermal management
Voltage regulation
Power factor correction
Explanation - A BMS monitors and controls battery cells but does not directly manage power factor.
Correct answer is: Power factor correction
Q.17 What does the acronym ‘SCADA’ stand for in power system operations?
Supervisory Control And Data Acquisition
Smart Control And Distribution Automation
Signal Control And Data Analysis
Solar Control And Data Array
Explanation - SCADA systems collect real‑time data and provide remote control over power system assets.
Correct answer is: Supervisory Control And Data Acquisition
Q.18 Which factor primarily limits the use of tidal energy?
Seasonal variability
Predictability
Limited geographic locations
High maintenance costs
Explanation - Tidal power requires specific coastal sites, limiting its widespread deployment.
Correct answer is: Limited geographic locations
Q.19 What is the main purpose of a ‘smart inverter’ in a PV system?
Increase panel output
Regulate grid voltage and frequency
Store excess energy
Generate wind power
Explanation - Smart inverters can provide grid services such as voltage support, frequency response, and fault ride‑through.
Correct answer is: Regulate grid voltage and frequency
Q.20 Which of these is an example of a variable renewable energy source?
Solar PV
Onshore wind
Geothermal
Hydropower
Explanation - Solar PV output depends on sunlight, making it variable, while geothermal and hydropower are more constant.
Correct answer is: Solar PV
Q.21 What is the typical output frequency of the U.S. electric grid?
50 Hz
60 Hz
75 Hz
100 Hz
Explanation - The U.S. grid operates at 60 cycles per second (60 Hz).
Correct answer is: 60 Hz
Q.22 Which of the following best describes a ‘grid‑forming’ inverter?
An inverter that follows a grid signal
An inverter that can create its own voltage and frequency
An inverter that only supplies power to local loads
An inverter that stores energy
Explanation - Grid‑forming inverters establish voltage and frequency reference, allowing islanded operation.
Correct answer is: An inverter that can create its own voltage and frequency
Q.23 Which type of renewable energy typically requires the largest land area per MW installed?
Solar PV
Wind turbine
Hydropower
Geothermal
Explanation - Solar PV needs extensive panels spread over large areas, more so than the other listed sources.
Correct answer is: Solar PV
Q.24 Which component in a battery inverter ensures that the battery does not over‑discharge?
Current limiter
Voltage supervisor
Battery management system
Thermal fuse
Explanation - A BMS monitors state‑of‑charge to prevent excessive discharge.
Correct answer is: Battery management system
Q.25 What is the role of a ‘differential protection relay’ in a smart grid?
Detect voltage imbalances
Detect overcurrent in a faulted phase
Protect against voltage surges
Regulate power factor
Explanation - Differential relays compare currents in series components to detect faults.
Correct answer is: Detect overcurrent in a faulted phase
Q.26 Which renewable source is most likely to cause voltage flicker on the grid?
Wind turbines
Solar panels
Hydropower plants
Geothermal plants
Explanation - Rapid wind speed changes can cause sudden output variations, leading to voltage flicker.
Correct answer is: Wind turbines
Q.27 What is the primary function of a ‘step‑down transformer’ in a distribution system?
Increase voltage
Decrease voltage
Store energy
Convert AC to DC
Explanation - Step‑down transformers reduce high transmission voltages to distribution levels.
Correct answer is: Decrease voltage
Q.28 Which of the following best describes an ‘energy arbitrage’ strategy?
Buying energy at high prices and selling it at low prices
Storing energy when prices are low and selling when prices are high
Generating renewable energy continuously
Never selling energy back to the grid
Explanation - Energy arbitrage exploits price differentials to profit from storage.
Correct answer is: Storing energy when prices are low and selling when prices are high
Q.29 Which of the following is NOT typically a benefit of battery storage in a smart grid?
Load leveling
Frequency regulation
Increase system inertia
Instantaneous energy supply
Explanation - Batteries have little mechanical inertia; they mainly provide rapid power support.
Correct answer is: Increase system inertia
Q.30 What is the main reason for using ‘phased array antennas’ in power line communication?
To increase range
To reduce interference
To provide multiple data channels
To lower cost
Explanation - Phased arrays can steer signals to avoid interfering with other devices.
Correct answer is: To reduce interference
Q.31 Which of the following is a key advantage of using ‘demand‑side management’?
Reduces system losses
Increases peak load
Improves reliability
Decreases renewable integration
Explanation - By shifting or reducing load, the system becomes more stable and reliable.
Correct answer is: Improves reliability
Q.32 What type of inverter is needed when connecting a wind turbine directly to a power line?
Grid‑forming inverter
Grid‑following inverter
Battery inverter
Standalone inverter
Explanation - A grid‑following inverter synchronizes with the grid and feeds power into it.
Correct answer is: Grid‑following inverter
Q.33 Which of the following is a characteristic of a ‘photovoltaic cell’?
It generates electricity from wind
It converts light to electrical energy
It stores electricity in a chemical form
It requires a battery to operate
Explanation - Photovoltaic cells produce direct current when exposed to sunlight.
Correct answer is: It converts light to electrical energy
Q.34 What is a major drawback of using large‑scale solar farms?
High output variability
Limited scalability
High initial land cost
High maintenance of turbines
Explanation - Solar farms require vast land areas, which can be expensive or hard to acquire.
Correct answer is: High initial land cost
Q.35 Which component of a wind turbine directly converts kinetic energy into electrical energy?
Blades
Generator
Yaw drive
Tower
Explanation - The generator transforms the rotational mechanical energy into electricity.
Correct answer is: Generator
Q.36 What does ‘N-1 security’ mean in power system operations?
The system can withstand the loss of one line or component
The system must add one extra generator
The system must operate with one extra voltage level
The system can handle one extra load
Explanation - N-1 security ensures reliability by maintaining operation after a single outage.
Correct answer is: The system can withstand the loss of one line or component
Q.37 Which of the following is NOT a benefit of integrating storage with renewable energy?
Time‑shift of renewable power
Improved voltage stability
Elimination of renewable resources
Peak shaving
Explanation - Storage complements renewables; it does not remove them from the system.
Correct answer is: Elimination of renewable resources
Q.38 What is the main function of a ‘phasor measurement unit (PMU)’ in a smart grid?
Generate power
Measure power system phasors in real time
Store energy
Control load
Explanation - PMUs provide high‑speed measurements of voltage and current for monitoring and control.
Correct answer is: Measure power system phasors in real time
Q.39 Which of the following is an example of a ‘distributed energy resource’ (DER)?
Large power plant
Rooftop solar panel
Hydro reservoir
Transmission line
Explanation - DERs are small, decentralized generation or storage units near the load.
Correct answer is: Rooftop solar panel
Q.40 Which of these is a type of communication protocol used in power line communications?
Ethernet
Power Line Carrier (PLC)
Bluetooth
USB
Explanation - PLC uses existing power lines for data transmission in grid communications.
Correct answer is: Power Line Carrier (PLC)
Q.41 Which renewable resource has the highest capacity factor among the options?
Onshore wind
Solar PV
Offshore wind
Geothermal
Explanation - Geothermal power plants operate continuously, giving them a high capacity factor.
Correct answer is: Geothermal
Q.42 Which of the following is NOT a function of a smart meter?
Record energy consumption
Transmit data to utilities
Generate electricity
Enable dynamic pricing
Explanation - Smart meters measure consumption, not generate power.
Correct answer is: Generate electricity
Q.43 What is the main reason for using ‘battery‑backed UPS systems’ in grid infrastructure?
To provide backup power during outages
To increase transmission voltage
To reduce solar panel output
To store wind energy
Explanation - UPS systems supply power when the main grid fails, maintaining critical services.
Correct answer is: To provide backup power during outages
Q.44 Which of the following is a typical application of ‘power electronic converters’?
Water purification
Signal processing
AC to DC conversion
Mechanical steering
Explanation - Power electronics convert and control electrical power between different forms.
Correct answer is: AC to DC conversion
Q.45 In a microgrid, what is the purpose of a ‘black start’ capability?
To start the grid after a blackout without external supply
To reduce power consumption
To increase grid frequency
To control voltage levels
Explanation - Black‑start allows the system to restart using internal or distributed sources.
Correct answer is: To start the grid after a blackout without external supply
Q.46 Which of the following best describes a ‘grid‑forming inverter’?
An inverter that follows a grid voltage reference
An inverter that can set its own voltage and frequency
An inverter that only stores energy
An inverter that measures current
Explanation - Grid‑forming inverters establish the grid's reference, enabling islanded operation.
Correct answer is: An inverter that can set its own voltage and frequency
Q.47 What is the primary goal of ‘frequency regulation’ in a power system?
Maintain voltage level
Maintain system frequency near nominal
Increase load
Reduce power loss
Explanation - Frequency regulation keeps the system’s frequency close to its target (e.g., 60 Hz).
Correct answer is: Maintain system frequency near nominal
Q.48 Which of these is a challenge associated with offshore wind farms?
High soil resistance
Limited wind speeds
Harsh marine environment
Low power output
Explanation - Saltwater and waves increase corrosion and maintenance demands.
Correct answer is: Harsh marine environment
Q.49 What does the term ‘net metering’ refer to in the context of residential solar PV?
Paying a flat rate for solar electricity
Measuring solar output only
Credit for excess solar power sent to the grid
Measuring consumption only
Explanation - Net metering allows homeowners to offset their consumption by sending surplus energy back to the grid.
Correct answer is: Credit for excess solar power sent to the grid
Q.50 Which of the following is NOT a characteristic of a ‘grid‑following inverter’?
It synchronizes with grid voltage
It can supply power without grid reference
It supports voltage regulation
It is used in renewable integration
Explanation - Grid‑following inverters depend on an existing grid to operate.
Correct answer is: It can supply power without grid reference
Q.51 What is a typical purpose of a ‘smart controller’ in a residential PV system?
To generate electricity
To monitor and optimize power flow
To store energy
To convert DC to AC
Explanation - Smart controllers manage energy usage, maximizing self‑consumption and reducing grid draw.
Correct answer is: To monitor and optimize power flow
Q.52 Which of the following technologies is used for long‑distance transmission of renewable power?
Low‑Voltage DC
High‑Voltage DC (HVDC)
Standard AC
Magnetic induction
Explanation - HVDC reduces losses over long distances and connects remote renewable sites to the grid.
Correct answer is: High‑Voltage DC (HVDC)
Q.53 Which of the following is a benefit of using a ‘smart grid’?
Higher power losses
Reduced load forecasting
Improved reliability and efficiency
Increased fossil fuel use
Explanation - Smart grids provide real‑time monitoring and control for better operations.
Correct answer is: Improved reliability and efficiency
Q.54 What is the main function of a ‘dynamic line rating (DLR)’ system?
Set a fixed line capacity
Adjust line ratings based on real‑time weather
Reduce line temperature
Increase line voltage
Explanation - DLR updates the allowable load on a line based on current conditions.
Correct answer is: Adjust line ratings based on real‑time weather
Q.55 Which type of inverter is required for a wind turbine that operates without a grid connection?
Grid‑forming inverter
Grid‑following inverter
Battery inverter
Standalone inverter
Explanation - Grid‑forming inverters can create a stable voltage and frequency for isolated operation.
Correct answer is: Grid‑forming inverter
Q.56 What does ‘capacity factor’ describe for a power plant?
Maximum possible output
Average output relative to nameplate capacity
Peak output during a crisis
Minimum output during low demand
Explanation - Capacity factor indicates how often a plant runs near its maximum output.
Correct answer is: Average output relative to nameplate capacity
Q.57 Which of the following best describes the term ‘frequency droop’?
Decrease in frequency as load increases
Increase in frequency as load increases
Constant frequency regardless of load
Sudden frequency drop to zero
Explanation - Frequency droop is a control method where generator output reduces as frequency drops.
Correct answer is: Decrease in frequency as load increases
Q.58 What is a main advantage of ‘demand response programs’?
Increases renewable penetration
Raises electricity prices
Reduces grid congestion
Increases fossil fuel use
Explanation - By shifting or cutting load, demand response eases stress on the grid.
Correct answer is: Reduces grid congestion
Q.59 Which of the following is a common communication medium for smart grid data?
Wi‑Fi
Power Line Communication (PLC)
Fiber Optic
All of the above
Explanation - Smart grids use multiple communication methods, including Wi‑Fi, PLC, and fiber.
Correct answer is: All of the above
Q.60 Which component of a solar PV system is responsible for converting DC to AC?
Inverter
Panel
Controller
Battery
Explanation - The inverter performs DC‑to‑AC conversion for grid or load compatibility.
Correct answer is: Inverter
Q.61 What is the main challenge of ‘intermittent renewable sources’?
Constant power output
Predictable generation
Variable output over time
Unlimited storage
Explanation - Intermittent sources like solar and wind produce power unpredictably, affecting grid balance.
Correct answer is: Variable output over time
Q.62 Which of the following best explains ‘grid resilience’?
Speed of power generation
Ability to recover quickly from disturbances
High power factor
Large transmission lines
Explanation - Grid resilience refers to how swiftly the system returns to normal operation after a fault.
Correct answer is: Ability to recover quickly from disturbances
Q.63 Which of the following is a benefit of using ‘bifacial solar panels’?
Higher efficiency due to light from both sides
Lower cost than standard panels
No need for inverters
They work only at night
Explanation - Bifacial panels can capture reflected light, increasing overall output.
Correct answer is: Higher efficiency due to light from both sides
Q.64 What is the primary purpose of a ‘load‑sharing’ scheme in a distributed generation system?
To balance power among generators
To increase voltage
To control frequency
To store energy
Explanation - Load sharing ensures each generator contributes appropriately to the total load.
Correct answer is: To balance power among generators
Q.65 Which of the following best describes a ‘grid‑connected inverter’?
An inverter that operates without the grid
An inverter that synchronizes with the grid
An inverter that stores energy
An inverter that measures current
Explanation - Grid‑connected inverters supply power to the grid while following its voltage and frequency.
Correct answer is: An inverter that synchronizes with the grid
Q.66 What is the main function of a ‘differential protection relay’?
Detect overcurrent in a faulted phase
Monitor voltage levels
Control power factor
Regulate temperature
Explanation - Differential relays compare currents to identify faults, disconnecting the faulted section.
Correct answer is: Detect overcurrent in a faulted phase
Q.67 Which of the following best describes the term ‘PV module output power’?
Maximum possible power at any time
Power produced under standard test conditions
Average power over a year
Power produced at night
Explanation - PV module rating is measured under STC (1000 W/m² irradiance, 25 °C, AM 1.5 spectrum).
Correct answer is: Power produced under standard test conditions
Q.68 What is the main advantage of ‘energy forecasting’ in renewable integration?
Reduces wind speed
Predicts renewable output for planning
Increases solar panel size
Eliminates storage needs
Explanation - Forecasting allows grid operators to anticipate generation, reducing variability risks.
Correct answer is: Predicts renewable output for planning
Q.69 Which of the following is NOT a typical characteristic of a ‘grid‑forming inverter’?
It sets its own voltage reference
It can operate in islanded mode
It relies on grid reference for operation
It can supply frequency support
Explanation - Grid‑forming inverters establish their own voltage/frequency without needing an external grid.
Correct answer is: It relies on grid reference for operation
Q.70 Which device is used to protect power electronic converters from overvoltage?
Fuse
Surge arrester
Capacitor
Inductor
Explanation - Surge arresters clamp high voltage spikes, protecting sensitive electronics.
Correct answer is: Surge arrester
Q.71 Which of the following best describes a ‘phased‑array antenna’?
A single large antenna
An array of antennas whose signals can be electronically steered
A cable‑based antenna
An antenna that only transmits, not receives
Explanation - Phased‑array antennas adjust phase shifts to steer beams without mechanical movement.
Correct answer is: An array of antennas whose signals can be electronically steered
Q.72 What does the term ‘grid stability’ refer to?
Consistent voltage and frequency
High power output
Large storage capacity
Long transmission lines
Explanation - Stability ensures that voltage and frequency stay within acceptable limits for safe operation.
Correct answer is: Consistent voltage and frequency
Q.73 Which of the following is a potential drawback of battery storage?
Limited cycle life
No environmental impact
Unlimited capacity
Low cost
Explanation - Batteries degrade with each charge‑discharge cycle, limiting their lifespan.
Correct answer is: Limited cycle life
Q.74 What is a primary function of a ‘smart inverter’ in a PV system?
To reduce panel temperature
To regulate grid voltage and frequency
To increase panel area
To store excess energy
Explanation - Smart inverters provide grid services like voltage support and reactive power control.
Correct answer is: To regulate grid voltage and frequency
Q.75 Which of the following is a common application of ‘microgrids’?
Powering large cities
Remote or critical sites like hospitals
Generating nuclear power
Producing oil
Explanation - Microgrids can supply reliable power to isolated or critical facilities.
Correct answer is: Remote or critical sites like hospitals
Q.76 Which of the following is a key benefit of integrating ‘HVDC’ links into the grid?
Reduced transmission losses over long distances
Higher frequency operation
Increased reliance on fossil fuels
Decreased stability
Explanation - HVDC reduces line losses, making long‑range power transport more efficient.
Correct answer is: Reduced transmission losses over long distances
Q.77 What is a major advantage of using ‘flywheel energy storage’?
Long‑term energy storage
High power density and fast response
Low cost
No maintenance
Explanation - Flywheels deliver energy in seconds, ideal for frequency regulation.
Correct answer is: High power density and fast response
Q.78 Which of the following is a typical application of ‘phaser measurement units (PMUs)’?
To monitor voltage, current, and frequency in real time
To store energy
To generate power
To control transformer taps
Explanation - PMUs provide high‑speed synchronized measurements for grid monitoring.
Correct answer is: To monitor voltage, current, and frequency in real time
Q.79 Which of the following best describes ‘demand response’?
Increasing load when renewable output is high
Reducing load during low renewable output
Keeping load constant at all times
Adding more generators
Explanation - Demand response programs shift or reduce consumption when supply is constrained.
Correct answer is: Reducing load during low renewable output
Q.80 Which of the following is a characteristic of a ‘grid‑following inverter’?
It can create its own voltage reference
It synchronizes with an external grid reference
It does not need a grid connection
It only stores energy
Explanation - Grid‑following inverters rely on an existing grid for voltage and frequency.
Correct answer is: It synchronizes with an external grid reference
Q.81 What is the main advantage of ‘battery‑backed UPS’ systems?
Increases load
Provides backup power during outages
Reduces grid frequency
Stores renewable energy for months
Explanation - UPS systems keep critical loads running when the main grid fails.
Correct answer is: Provides backup power during outages
Q.82 Which of the following is a benefit of ‘smart meter’ deployment?
Real‑time energy consumption data
Higher consumption
Manual meter reading
No impact on the grid
Explanation - Smart meters enable accurate, timely billing and demand management.
Correct answer is: Real‑time energy consumption data
Q.83 Which of the following is NOT a typical characteristic of a ‘smart inverter’?
Can provide reactive power support
Can adjust output frequency
Can store energy
Can communicate with other devices
Explanation - Inverters convert DC to AC; they do not store energy themselves.
Correct answer is: Can store energy
Q.84 What is the main benefit of using a ‘dynamic line rating’ system?
Maintains fixed line capacity
Adapts line capacity to real‑time conditions
Reduces line temperature
Increases line voltage
Explanation - DLR increases or decreases line capacity based on weather and temperature data.
Correct answer is: Adapts line capacity to real‑time conditions
Q.85 Which of the following is a major challenge of integrating wind power into the grid?
Constant output
Large land use
Variable output and low inertia
Unlimited storage
Explanation - Wind’s variability and lack of mechanical inertia can destabilize the grid.
Correct answer is: Variable output and low inertia
Q.86 Which of the following best describes a ‘grid‑forming inverter’s capability for islanding?
It can disconnect from the grid and operate independently
It requires a grid to operate
It can only operate in a connected mode
It cannot provide any grid support
Explanation - Grid‑forming inverters can create a local grid reference when the main grid fails.
Correct answer is: It can disconnect from the grid and operate independently
Q.87 Which of the following is a benefit of ‘hydropower’ as a renewable resource?
Low variability
No water usage
High land cost
High maintenance
Explanation - Hydropower output can be controlled, providing stable generation with low variability.
Correct answer is: Low variability
Q.88 Which of the following best explains the term ‘capacity factor’?
Maximum output of a plant
Average output relative to nameplate capacity
Minimum output during low demand
Total installed capacity of a region
Explanation - Capacity factor measures how often a plant operates near its maximum possible output.
Correct answer is: Average output relative to nameplate capacity
Q.89 What is a primary role of ‘smart grid’ communication networks?
Providing high‑speed internet
Enabling real‑time data exchange for grid control
Running HVAC systems
Increasing fossil fuel consumption
Explanation - Communication networks support real‑time monitoring and control of the grid.
Correct answer is: Enabling real‑time data exchange for grid control
Q.90 Which of the following is a common application for ‘hydrogen storage’ in renewable grids?
Short‑term frequency regulation
Seasonal energy storage
Instantaneous load shedding
Real‑time power factor correction
Explanation - Hydrogen can store energy for months or seasons, ideal for seasonal variability.
Correct answer is: Seasonal energy storage
Q.91 Which of the following best describes a ‘smart controller’ in a residential PV system?
An inverter that converts DC to AC
A device that monitors and optimizes power flow
A battery that stores energy
A transformer that steps up voltage
Explanation - Smart controllers manage consumption and generation to maximize self‑use and grid interaction.
Correct answer is: A device that monitors and optimizes power flow
Q.92 Which of the following is NOT a typical characteristic of a ‘grid‑following inverter’?
It requires a voltage reference from the grid
It can provide voltage support to the grid
It can operate independently of the grid
It can deliver active power to the grid
Explanation - Grid‑following inverters need an external grid reference for operation.
Correct answer is: It can operate independently of the grid
Q.93 Which of the following is an example of a renewable energy source that can be used for energy storage?
Wind turbines
Solar panels
Hydropower reservoirs
Biogas plants
Explanation - Pumped‑storage hydropower uses reservoirs to store and release energy as needed.
Correct answer is: Hydropower reservoirs
Q.94 Which of the following is a typical benefit of integrating ‘energy storage’ with renewable generation?
Eliminate need for grid
Increase power losses
Improve grid reliability
Reduce renewable penetration
Explanation - Storage buffers variability, smoothing output and enhancing reliability.
Correct answer is: Improve grid reliability
Q.95 What is the main purpose of a ‘smart meter’ in a residential setting?
Generate electricity
Record and transmit energy consumption
Store energy
Control appliances
Explanation - Smart meters measure consumption and send data to utilities for billing and monitoring.
Correct answer is: Record and transmit energy consumption
Q.96 Which of the following is a key component of a ‘photovoltaic system’?
Inverter
Transformer
Battery
All of the above
Explanation - PV systems typically include panels, inverter, and often a battery or transformer.
Correct answer is: All of the above
Q.97 Which of the following best explains the term ‘frequency droop’?
Decrease in frequency as load increases
Increase in frequency as load increases
No change in frequency
Sudden frequency drop to zero
Explanation - Frequency droop is a control strategy where generator output decreases as frequency drops.
Correct answer is: Decrease in frequency as load increases
Q.98 What is the main advantage of using ‘smart grid’ technology?
Higher losses
Real‑time monitoring and control
Increased fossil fuel use
Lower reliability
Explanation - Smart grids enable dynamic monitoring, improved reliability, and efficient resource integration.
Correct answer is: Real‑time monitoring and control
Q.99 Which of the following best describes a ‘grid‑forming inverter’s ability to provide inertia?
It provides infinite inertia
It provides synthetic inertia via fast frequency response
It has no inertia at all
It reduces inertia to zero
Explanation - Grid‑forming inverters can emulate inertia by rapidly adjusting output to frequency changes.
Correct answer is: It provides synthetic inertia via fast frequency response
Q.100 Which of the following is NOT a typical advantage of using renewable energy sources?
Reduced greenhouse gas emissions
Dependence on weather conditions
Lower operating costs after installation
High reliability
Explanation - Renewable sources can be intermittent, affecting reliability without proper integration.
Correct answer is: High reliability
Q.101 Which of the following is a main function of a ‘battery management system (BMS)’?
Control voltage of the grid
Monitor and balance state of charge in battery cells
Generate power
Store energy
Explanation - A BMS tracks each cell’s state and ensures balanced charging and discharging.
Correct answer is: Monitor and balance state of charge in battery cells
Q.102 What is the main benefit of integrating 'hydro power' with solar PV?
Increases solar panel cost
Provides steady power to balance solar intermittency
Reduces water usage
Decreases grid frequency
Explanation - Hydro plants can quickly adjust output to complement variable solar generation.
Correct answer is: Provides steady power to balance solar intermittency
Q.103 Which of the following best describes a ‘smart grid’s capability for real‑time data exchange?
It uses analog signals only
It can transmit data over power lines or fiber optics
It operates without any communication
It uses only telephone lines
Explanation - Smart grids utilize power line communication (PLC) and fiber for data transmission.
Correct answer is: It can transmit data over power lines or fiber optics
Q.104 Which of the following is a primary challenge for 'intermittent renewable sources' like solar and wind?
Continuous output
Predictable generation
Variable output over time
Unlimited storage
Explanation - Intermittent sources produce power that fluctuates with weather and time of day.
Correct answer is: Variable output over time
Q.105 What is the main purpose of a 'phasing relay' in a power system?
Detect overvoltage
Synchronize phase angles
Control current
Measure frequency
Explanation - Phasing relays ensure proper phase alignment between sources before connecting them.
Correct answer is: Synchronize phase angles
Q.106 Which of the following best describes a 'grid‑following inverter’s operation mode?
It sets its own voltage reference
It synchronizes with the grid’s voltage and frequency
It operates offline only
It provides only reactive power
Explanation - Grid‑following inverters align their output with the existing grid reference.
Correct answer is: It synchronizes with the grid’s voltage and frequency
Q.107 Which of the following is an example of a 'demand response' action?
Turning off lights during peak hours
Increasing load during low generation periods
Adding more generators
Generating more solar power
Explanation - Demand response reduces consumption during high‑cost periods to balance supply and demand.
Correct answer is: Turning off lights during peak hours
Q.108 What is the main role of 'energy storage' in a smart grid?
Increasing grid frequency
Storing excess renewable energy for later use
Generating solar power
Controlling voltage at the source
Explanation - Energy storage smooths variability by holding surplus power until it is needed.
Correct answer is: Storing excess renewable energy for later use
Q.109 Which of the following best explains 'power electronic converters'?
Devices that convert electrical power from one form to another
Devices that generate electricity
Devices that store energy
Devices that measure voltage
Explanation - Power electronics convert AC to DC or DC to AC, control power flow, and shape waveforms.
Correct answer is: Devices that convert electrical power from one form to another
Q.110 Which of the following is NOT a typical feature of a 'smart inverter'?
Voltage and frequency support
Real‑time communication with the grid
Storage of excess energy
Rapid response to grid changes
Explanation - Inverters convert DC to AC; storage is handled by batteries or other storage devices.
Correct answer is: Storage of excess energy
Q.111 What is a 'black start' capability?
The ability to restart the grid without external power
The ability to start the grid using external power only
The ability to shut down the grid during a blackout
The ability to increase grid voltage automatically
Explanation - Black start allows the grid to recover from a full blackout using internal sources.
Correct answer is: The ability to restart the grid without external power
Q.112 Which of the following best describes 'frequency regulation'?
Maintaining voltage at a constant level
Keeping system frequency within acceptable limits
Increasing system power
Reducing load demand
Explanation - Frequency regulation ensures that the grid’s frequency stays close to its nominal value.
Correct answer is: Keeping system frequency within acceptable limits
Q.113 Which of the following is a common method for forecasting renewable output?
Random guess
Weather prediction models
Constant output assumption
Ignoring variability
Explanation - Forecasting relies on weather data to predict how much power a renewable will generate.
Correct answer is: Weather prediction models
Q.114 What does 'N-1 security' guarantee in power systems?
The system can handle the loss of one component
The system can add one more generator
The system can operate without any component
The system can handle two simultaneous faults
Explanation - N‑1 security means the grid remains operational after the failure of any single element.
Correct answer is: The system can handle the loss of one component
Q.115 Which of the following is a major benefit of 'battery storage' in a residential PV system?
Higher cost of electricity
Reduced self‑consumption
Increased backup power during outages
Higher power losses
Explanation - Batteries provide backup power when the grid fails, keeping critical loads running.
Correct answer is: Increased backup power during outages
Q.116 What is the primary function of a 'phaser measurement unit (PMU)'?
Generate power
Store energy
Monitor voltage, current, and frequency in real time
Control transformers
Explanation - PMUs provide high‑speed, synchronized measurements to support grid monitoring.
Correct answer is: Monitor voltage, current, and frequency in real time
Q.117 Which of the following best describes 'smart grid's use of data analytics?
Storing data for future use only
Using data to improve grid operations, forecasting, and reliability
Ignoring data for simplicity
Only used for billing
Explanation - Data analytics helps operators optimize resources, predict outages, and enhance reliability.
Correct answer is: Using data to improve grid operations, forecasting, and reliability
Q.118 Which of the following best describes a 'grid‑forming inverter’ in a microgrid?
An inverter that follows the grid voltage
An inverter that can generate its own voltage and frequency
An inverter that only stores energy
An inverter that measures current
Explanation - Grid‑forming inverters act as a local voltage source and can operate in island mode.
Correct answer is: An inverter that can generate its own voltage and frequency
Q.119 Which of the following best describes a 'differential protection relay'?
A relay that compares currents in a circuit to detect faults
A relay that measures voltage only
A relay that controls the transformer tap
A relay that stores energy
Explanation - Differential relays detect faults by comparing current entering and leaving a protected zone.
Correct answer is: A relay that compares currents in a circuit to detect faults
Q.120 Which of the following is NOT a typical communication protocol used in smart grids?
Modbus
DNP3
Bluetooth
IEC 61850
Explanation - Bluetooth is not commonly used in utility‑grade communications due to range and reliability constraints.
Correct answer is: Bluetooth
Q.121 What is the main advantage of 'dynamic line rating (DLR)'?
Fixed line capacity
Real‑time capacity adjustment based on weather conditions
Reduction in line temperature
Increasing voltage on the line
Explanation - DLR updates the safe operating limits of lines to reflect actual environmental conditions.
Correct answer is: Real‑time capacity adjustment based on weather conditions
Q.122 Which of the following best explains the term 'grid resilience'?
Ability to recover quickly from disturbances
Ability to increase load during peak times
Ability to increase voltage limits
Ability to reduce frequency
Explanation - Grid resilience refers to how quickly the system can return to normal after an event.
Correct answer is: Ability to recover quickly from disturbances
Q.123 Which of the following is NOT a benefit of using 'pumped‑storage hydropower' for renewable integration?
Long‑term energy storage
Fast response to frequency changes
High capital cost
Large land requirement
Explanation - While pumped‑storage can respond relatively quickly, it is slower than batteries for frequency regulation.
Correct answer is: Fast response to frequency changes
Q.124 What is the primary function of a 'smart controller' in a residential PV system?
Monitor and optimize power flow between PV, battery, and grid
Generate electricity from the battery
Store excess solar power
Convert DC to AC
Explanation - Smart controllers manage how energy is used, stored, and exported to maximize self‑consumption.
Correct answer is: Monitor and optimize power flow between PV, battery, and grid
Q.125 Which of the following is a typical application of 'phaser measurement units (PMUs)' in a smart grid?
Real‑time monitoring of voltage, current, and frequency
Storing excess solar power
Generating wind power
Controlling transformer tap settings
Explanation - PMUs provide real‑time data that enable dynamic control and protection of the grid.
Correct answer is: Real‑time monitoring of voltage, current, and frequency
Q.126 Which of the following best describes the 'frequency droop' control strategy?
Decrease output as frequency increases
Increase output as frequency decreases
Keep output constant regardless of frequency
Eliminate frequency changes
Explanation - Droop control reduces frequency deviations by adjusting generator output proportionally.
Correct answer is: Increase output as frequency decreases
Q.127 Which of the following is NOT typically a benefit of integrating 'energy storage' with renewable generation?
Improved grid reliability
Increased renewable penetration
Higher power losses
Reduced need for peaking plants
Explanation - Energy storage usually reduces overall losses by smoothing generation, not increasing them.
Correct answer is: Higher power losses
Q.128 What is the primary purpose of a 'phasing relay' in a power system?
Synchronize phase angles between different parts of the grid
Detect overvoltage
Control current
Measure frequency
Explanation - Phasing relays ensure that two systems are in phase before they are connected.
Correct answer is: Synchronize phase angles between different parts of the grid
Q.129 Which of the following best describes a 'grid‑forming inverter’ in an islanded microgrid?
It follows an external grid reference
It can act as a voltage source and regulate frequency
It operates only when connected to the main grid
It provides only reactive power
Explanation - Grid‑forming inverters provide voltage reference and can maintain operation when isolated.
Correct answer is: It can act as a voltage source and regulate frequency
Q.130 Which of the following is a major advantage of using 'smart inverters' in renewable systems?
They provide voltage regulation and reactive power support
They generate more power than standard inverters
They store energy
They have no communication capability
Explanation - Smart inverters can actively support grid voltage, frequency, and provide reactive power.
Correct answer is: They provide voltage regulation and reactive power support
Q.131 Which of the following best describes 'energy arbitrage'?
Buying energy at high prices and selling it at low prices
Selling energy at high prices and buying it at low prices
Storing energy when prices are low and selling when prices are high
Storing energy all the time
Explanation - Energy arbitrage exploits price differences between times of high and low demand.
Correct answer is: Storing energy when prices are low and selling when prices are high
Q.132 Which of the following is a major challenge of 'intermittent renewable sources' such as wind and solar?
Constant power output
Predictable generation schedule
Variable output over time
Unlimited storage capacity
Explanation - Their output depends on weather and time, causing variability in supply.
Correct answer is: Variable output over time