Q.1 What is the primary function of an IoT device in a smart grid?
To generate electricity
To measure and report data
To replace transformers
To store energy
Explanation - IoT devices such as smart meters and sensors collect data on consumption, voltage, or temperature and transmit it for monitoring and control.
Correct answer is: To measure and report data
Q.2 Which communication protocol is most commonly used for low-power IoT devices in smart grids?
Wi‑Fi
Bluetooth Low Energy
LoRaWAN
Ethernet
Explanation - LoRaWAN provides long-range, low-power communication ideal for wide-area grid sensor deployments.
Correct answer is: LoRaWAN
Q.3 What does MQTT stand for in the context of IoT communications?
Message Queue Telemetry Transport
Maximum Queue Transmission Type
Mobile Quality of Transmission
Multi‑Queue Time Transfer
Explanation - MQTT is a lightweight publish/subscribe messaging protocol designed for small sensors and mobile devices.
Correct answer is: Message Queue Telemetry Transport
Q.4 Which layer of the OSI model does the TCP protocol operate on?
Application
Transport
Network
Physical
Explanation - TCP provides reliable, ordered delivery of data at the Transport layer (layer 4) of the OSI model.
Correct answer is: Transport
Q.5 What is the main advantage of using edge computing in a smart grid?
Centralized data storage
Reduced latency
Higher energy consumption
Simplified device firmware
Explanation - Edge computing processes data close to its source, minimizing delay and bandwidth usage for real‑time grid control.
Correct answer is: Reduced latency
Q.6 Which security measure is essential for protecting IoT devices in smart grids?
Open-source firmware
Public Wi‑Fi access
Strong authentication and encryption
No passwords
Explanation - Secure communication and identity verification prevent unauthorized access and data tampering.
Correct answer is: Strong authentication and encryption
Q.7 What does V2G stand for in the context of smart grids?
Voltage to Grid
Vehicle to Grid
Voltage to Generation
Variable to Grid
Explanation - V2G refers to the bi-directional flow of electricity between electric vehicles and the power grid.
Correct answer is: Vehicle to Grid
Q.8 Which protocol is commonly used for industrial automation in smart grid communication?
HTTP
OPC UA
FTP
SMTP
Explanation - OPC Unified Architecture (OPC UA) provides secure, reliable data exchange between industrial devices.
Correct answer is: OPC UA
Q.9 Which of the following is NOT a typical data type collected by smart grid sensors?
Power consumption
Voltage level
Ambient temperature
GPS location
Explanation - Smart grid sensors focus on electrical parameters; GPS is generally irrelevant unless tracking mobile units.
Correct answer is: GPS location
Q.10 What is the purpose of demand response programs in a smart grid?
Increase electricity prices
Encourage consumers to reduce or shift usage
Replace renewable energy sources
Disable smart meters
Explanation - Demand response balances supply and demand by incentivizing load reduction or shifting during peak periods.
Correct answer is: Encourage consumers to reduce or shift usage
Q.11 Which encryption standard is often used in securing MQTT communications?
AES‑128
DES
RC4
3DES
Explanation - AES‑128 provides strong, efficient encryption suitable for low‑power IoT devices.
Correct answer is: AES‑128
Q.12 Which of the following is a benefit of integrating IoT with predictive maintenance in smart grids?
Immediate load shedding
Early fault detection
Increased battery consumption
Elimination of human operators
Explanation - IoT sensors detect anomalies before failures occur, enabling proactive maintenance and reducing downtime.
Correct answer is: Early fault detection
Q.13 What does a smart meter primarily measure?
Water flow
Electricity usage
Internet traffic
Solar radiation
Explanation - Smart meters record electrical consumption in real time for billing and grid management.
Correct answer is: Electricity usage
Q.14 Which IoT communication technology uses a star network topology centered on a gateway?
Zigbee
Bluetooth Mesh
Wi‑Fi
LoRaWAN
Explanation - Wi‑Fi typically uses a star topology with a central access point serving all devices.
Correct answer is: Wi‑Fi
Q.15 In the context of smart grids, what is a 'gateway' device?
A device that generates power
A device that translates between protocols
A device that stores excess energy
A device that measures voltage
Explanation - Gateways bridge communication protocols (e.g., MQTT to Modbus) and connect local sensors to the wider network.
Correct answer is: A device that translates between protocols
Q.16 What is the main function of a PLC in a smart grid?
Data storage
Programmable logic control
Battery charging
Signal amplification
Explanation - PLCs automate control processes like switching, protection, and monitoring within the grid.
Correct answer is: Programmable logic control
Q.17 Which IoT protocol is designed for low‑power, long‑range communication in smart grid applications?
LTE-M
Wi‑Fi Direct
BLE
LoRaWAN
Explanation - LoRaWAN offers battery‑friendly, wide‑area connectivity ideal for distributed grid sensors.
Correct answer is: LoRaWAN
Q.18 Which of the following best describes the 'publish/subscribe' model?
Central server sends data to all devices
Devices send data only to a single endpoint
Devices publish messages to topics and subscribers receive them
Devices operate in peer‑to‑peer fashion
Explanation - Publish/subscribe decouples senders and receivers via a message broker and topics.
Correct answer is: Devices publish messages to topics and subscribers receive them
Q.19 Which sensor is typically used to measure voltage in a smart grid?
Current transformer
Temperature sensor
Voltage transformer
Pressure sensor
Explanation - Voltage transformers isolate and reduce voltage for safe measurement by the sensor.
Correct answer is: Voltage transformer
Q.20 What is the purpose of a 'time‑of‑use' tariff in a smart grid?
To charge a flat rate for all customers
To incentivize energy usage during off‑peak periods
To punish customers for high usage
To provide unlimited free electricity
Explanation - Time‑of‑use rates vary by time of day, encouraging load shifting to reduce peak demand.
Correct answer is: To incentivize energy usage during off‑peak periods
Q.21 Which of the following is a common vulnerability in IoT smart meters?
Weak encryption
Excessive battery life
Open-source firmware
Large display
Explanation - Weak or absent encryption can allow attackers to intercept or alter meter data.
Correct answer is: Weak encryption
Q.22 Which type of data is NOT typically sent from a smart grid sensor to the control center?
Power quality metrics
Weather forecasts
Energy consumption readings
Voltage waveforms
Explanation - While weather data can influence grid operations, it is usually sourced from separate weather stations, not local sensors.
Correct answer is: Weather forecasts
Q.23 What is the main advantage of using MQTT over HTTP for IoT devices?
Higher bandwidth usage
Stateless communication
Lower overhead and efficient use of resources
Built‑in encryption
Explanation - MQTT is lightweight and well suited for devices with limited bandwidth and power.
Correct answer is: Lower overhead and efficient use of resources
Q.24 Which component is responsible for converting AC to DC in most smart grid communication modules?
Rectifier
Transformer
Inverter
Regulator
Explanation - Rectifiers convert alternating current from the grid into the direct current required by digital electronics.
Correct answer is: Rectifier
Q.25 In a smart grid, what does 'grid edge' refer to?
The high‑voltage transmission network
The point where the grid meets the consumer
The central control center
The last mile of power lines
Explanation - 'Grid edge' denotes the distribution network and local devices interacting with the wider system.
Correct answer is: The point where the grid meets the consumer
Q.26 Which protocol allows secure data exchange between industrial devices over the internet?
OPC UA
FTP
SMTP
SNMP
Explanation - OPC UA supports secure, scalable communication for industrial automation devices.
Correct answer is: OPC UA
Q.27 What is the primary goal of 'energy storage' in a smart grid?
To increase peak demand
To store excess renewable energy for later use
To generate electricity without fuel
To provide backup for IoT devices
Explanation - Energy storage buffers variability in generation, improving reliability and grid stability.
Correct answer is: To store excess renewable energy for later use
Q.28 Which of the following is a benefit of implementing edge analytics in smart grid IoT?
Higher latency
Reduced data volume sent to cloud
Increased battery drain
More complex network topology
Explanation - Edge analytics processes data locally, sending only essential insights, saving bandwidth.
Correct answer is: Reduced data volume sent to cloud
Q.29 What does 'TLS' stand for and why is it important for smart grid communication?
Transport Layer Security – protects data in transit
Traffic Light System – manages traffic lights
Time‑Limited Service – sets session timeouts
Topological Layer Segmentation – separates network layers
Explanation - TLS encrypts communication channels, ensuring confidentiality and integrity of transmitted data.
Correct answer is: Transport Layer Security – protects data in transit
Q.30 Which IoT device is typically used for real‑time monitoring of transformer health?
Smart thermostat
Vibration sensor
Humidity sensor
Light sensor
Explanation - Vibration sensors detect abnormal mechanical behavior, indicating transformer faults.
Correct answer is: Vibration sensor
Q.31 What is the purpose of a 'gateway' in a LoRaWAN network?
To generate power for nodes
To forward messages between LoRa nodes and the internet
To store sensor data locally
To act as a backup power supply
Explanation - LoRa gateways receive LoRa transmissions and forward them to the network server via IP.
Correct answer is: To forward messages between LoRa nodes and the internet
Q.32 Which component of a smart meter communicates with the utility's backend system?
LCD display
Communication module
Battery backup
Tamper sensor
Explanation - The communication module (e.g., cellular, RF) sends consumption data to the utility.
Correct answer is: Communication module
Q.33 Which of the following is a characteristic of 'mesh networking' used in IoT?
All nodes connect only to a central hub
Nodes can relay messages for each other
The network uses a star topology
It is always wired
Explanation - Mesh networks allow each node to forward data, providing redundancy and extended coverage.
Correct answer is: Nodes can relay messages for each other
Q.34 What does 'V2X' stand for in the context of smart grids?
Vehicle to e‑circuit
Vehicle to e‑network
Vehicle to any infrastructure
Voltage to energy exchange
Explanation - V2X refers to vehicle‑to‑everything communication, including vehicle‑to‑grid (V2G).
Correct answer is: Vehicle to any infrastructure
Q.35 Which type of sensor measures the flow of electrical current in a smart grid?
Current transformer
Voltage transformer
Temperature sensor
Pressure sensor
Explanation - Current transformers produce a scaled current signal safe for measurement and protection relays.
Correct answer is: Current transformer
Q.36 What is the main goal of 'load forecasting' in smart grids?
To increase power generation
To predict future electricity demand
To store excess energy
To shut down the grid during peaks
Explanation - Accurate forecasts enable efficient generation scheduling and resource allocation.
Correct answer is: To predict future electricity demand
Q.37 Which communication technology uses a star topology where each device connects to a central hub?
Zigbee
Bluetooth Mesh
Wi‑Fi
LoRaWAN
Explanation - Wi‑Fi typically operates in a star topology with a central access point.
Correct answer is: Wi‑Fi
Q.38 Which feature of MQTT makes it suitable for battery‑powered IoT devices?
Large packet size
Persistent sessions
Stateless operation
High bandwidth consumption
Explanation - Persistent sessions allow devices to resume communication after disconnection without re‑authentication.
Correct answer is: Persistent sessions
Q.39 Which protocol is commonly used for secure remote access to industrial devices?
Telnet
SSH
FTP
SNMPv1
Explanation - SSH provides encrypted remote command‑line access, protecting against eavesdropping.
Correct answer is: SSH
Q.40 Which type of battery is often used in smart meters for backup power?
Lead‑acid
Lithium‑ion
Nickel‑metal hydride
Alkaline
Explanation - Lead‑acid batteries are inexpensive and reliable for low‑power backup in meters.
Correct answer is: Lead‑acid
Q.41 What does 'TLS handshake' establish?
Physical connection between devices
Secure encrypted channel
Data transfer rate
Device firmware update
Explanation - The TLS handshake negotiates keys and certificates to secure the subsequent data exchange.
Correct answer is: Secure encrypted channel
Q.42 Which IoT protocol is designed for high‑throughput, low‑latency applications?
CoAP
MQTT
AMQP
HTTP
Explanation - AMQP provides reliable, message‑oriented communication suitable for industrial control.
Correct answer is: AMQP
Q.43 In a smart grid, what is the purpose of a 'protection relay'?
To store energy
To monitor voltage and current and disconnect faults
To measure temperature
To transmit data to the cloud
Explanation - Protection relays detect abnormal conditions and isolate faults to protect equipment.
Correct answer is: To monitor voltage and current and disconnect faults
Q.44 Which of the following is a common security attack on IoT smart grid devices?
Denial of Service
Brute‑force password attack
Eavesdropping on encrypted channels
All of the above
Explanation - Smart grid IoT devices can be targeted by DoS, brute‑force, and eavesdropping attacks.
Correct answer is: All of the above
Q.45 What is the main advantage of using NB‑IoT over LoRaWAN for smart grid applications?
Lower power consumption
Higher data rate
Better support for massive device density in urban areas
Longer range
Explanation - NB‑IoT provides robust coverage in dense environments with many devices.
Correct answer is: Better support for massive device density in urban areas
Q.46 Which of the following is NOT a typical component of a smart grid architecture?
Transmission network
Distribution network
Data analytics layer
Consumer kitchen appliances
Explanation - Smart grid architecture focuses on grid infrastructure, not individual household appliances.
Correct answer is: Consumer kitchen appliances
Q.47 Which of the following best describes a 'data lake' in smart grid analytics?
A physical storage facility for hard drives
A cloud storage location for raw data
A secure vault for encryption keys
A device for storing battery energy
Explanation - A data lake holds large volumes of raw, unstructured data for later processing.
Correct answer is: A cloud storage location for raw data
Q.48 Which communication method uses 'sparse' packets to conserve energy?
TCP
UDP
MQTT
HTTP
Explanation - MQTT sends small, efficient packets and supports keep‑alive to reduce power use.
Correct answer is: MQTT
Q.49 What does 'V2I' stand for in the context of smart grids?
Vehicle to infrastructure
Voltage to Internet
Vehicle to Industry
Voltage to I/O
Explanation - V2I refers to vehicle communication with roadside infrastructure for traffic and grid management.
Correct answer is: Vehicle to infrastructure
Q.50 Which device is used to measure power factor in a smart grid?
Power analyzer
Voltage transformer
Temperature sensor
Humidity sensor
Explanation - Power analyzers calculate power factor by measuring phase difference between voltage and current.
Correct answer is: Power analyzer
Q.51 Which feature of 'OPC UA' ensures secure communication?
Public key infrastructure (PKI)
No authentication
Broadcast only
No encryption
Explanation - OPC UA uses PKI for mutual authentication and encrypted data exchange.
Correct answer is: Public key infrastructure (PKI)
Q.52 What is the primary benefit of using 'data fusion' in smart grid analytics?
Increased data redundancy
Improved data accuracy and insight
Lower processing speed
Higher battery consumption
Explanation - Data fusion combines multiple data sources for more accurate analysis and decision‑making.
Correct answer is: Improved data accuracy and insight
Q.53 Which of the following best describes a 'grid‑edge controller'?
A central power plant
A device that manages local demand response
A high‑voltage transmission switch
An energy storage unit
Explanation - Grid‑edge controllers act locally to adjust loads and storage for stability.
Correct answer is: A device that manages local demand response
Q.54 Which encryption algorithm is used in WPA3 for Wi‑Fi security?
RC4
AES‑CCMP
DES
3DES
Explanation - WPA3 uses AES in Counter Mode with Cipher Block Chaining Message Authentication Code Protocol.
Correct answer is: AES‑CCMP
Q.55 What role does 'edge AI' play in smart grids?
Centralized data storage
Local real‑time decision making
Replacing all human operators
Generating electricity
Explanation - Edge AI analyzes data near the source, enabling instant responses without sending everything to the cloud.
Correct answer is: Local real‑time decision making
Q.56 Which sensor type is used to detect tampering in a smart meter?
Tamper sensor
Temperature sensor
Pressure sensor
Humidity sensor
Explanation - Tamper sensors trigger alerts when a meter is opened or physically disturbed.
Correct answer is: Tamper sensor
Q.57 What is the primary advantage of using 'public key cryptography' in IoT devices?
Simpler key distribution
Higher computational overhead
No need for certificates
Greater security with scalable key management
Explanation - Public key cryptography allows secure key exchange over insecure channels, essential for many IoT deployments.
Correct answer is: Greater security with scalable key management
Q.58 Which of the following is a characteristic of 'synchronous data acquisition' in a smart grid?
Samples at random intervals
Samples simultaneously across devices
Uses only analog signals
Does not require time stamps
Explanation - Synchronous acquisition ensures all data points are aligned in time for accurate analysis.
Correct answer is: Samples simultaneously across devices
Q.59 What is a typical use of 'time‑synchronized' measurement in smart grids?
To monitor weather patterns
To coordinate load shedding across the network
To track customer addresses
To control household appliances
Explanation - Time‑synchronized data allows precise coordination of control actions across the grid.
Correct answer is: To coordinate load shedding across the network
Q.60 Which of the following is NOT a typical benefit of implementing 'microgrids'?
Improved resilience
Reduced carbon footprint
Increased transmission losses
Localized control
Explanation - Microgrids operate locally, often reducing, not increasing, transmission losses.
Correct answer is: Increased transmission losses
Q.61 Which network protocol is commonly used for device firmware updates over the air in smart grids?
CoAP
SNMP
FTP
HTTP
Explanation - CoAP is lightweight and designed for constrained devices, making it suitable for OTA updates.
Correct answer is: CoAP
Q.62 What does 'RTU' stand for in power system instrumentation?
Remote Terminal Unit
Real‑time Unit
Radial Transmission Unit
Reference Time Unit
Explanation - RTUs are field devices that gather data and execute control commands in the grid.
Correct answer is: Remote Terminal Unit
Q.63 Which IoT connectivity option supports both narrowband and wideband applications?
Wi‑Fi
LoRaWAN
Zigbee
Bluetooth
Explanation - LoRaWAN can operate in narrowband mode for low data and wideband for higher throughput.
Correct answer is: LoRaWAN
Q.64 Which device monitors and controls power flow across a distribution feeder?
Load controller
Transformer tap changer
Circuit breaker
Voltage regulator
Explanation - Voltage regulators maintain voltage levels by adjusting tap settings on transformers.
Correct answer is: Voltage regulator
Q.65 What is the primary function of a 'synchronizer' in a smart grid?
To synchronize time stamps
To synchronize phase and frequency between sources
To synchronize device firmware versions
To synchronize battery levels
Explanation - Synchronizers ensure multiple power sources operate in phase and frequency for safe interconnection.
Correct answer is: To synchronize phase and frequency between sources
Q.66 Which of the following is an example of a 'distributed energy resource' (DER)?
Wind turbine
Coal power plant
Hydroelectric dam
Natural gas plant
Explanation - DERs are small‑scale, often renewable sources integrated at the distribution level.
Correct answer is: Wind turbine
Q.67 What does 'DNP3' stand for in power system communications?
Distributed Network Protocol 3
Data Node Protocol 3
Distributed Network Protocol
Dynamic Network Protocol
Explanation - DNP3 is a protocol for communication between SCADA systems and field devices.
Correct answer is: Distributed Network Protocol
Q.68 Which of the following is a key advantage of using 'cellular IoT' for smart grid devices?
Requires no infrastructure
Supports high data rates
Low cost of deployment
Unlimited battery life
Explanation - Cellular IoT can deliver higher bandwidth, useful for detailed telemetry and firmware updates.
Correct answer is: Supports high data rates
Q.69 What is the purpose of 'load forecasting' in a smart grid?
To reduce electricity production
To predict future electricity demand
To store excess renewable energy
To shut down the grid during low demand
Explanation - Accurate forecasting allows operators to schedule generation and manage resources efficiently.
Correct answer is: To predict future electricity demand
Q.70 Which IoT communication protocol is specifically designed for constrained devices and offers reliability through retransmission?
CoAP
MQTT
AMQP
HTTP
Explanation - CoAP is UDP‑based but includes features for reliable message delivery, suitable for IoT.
Correct answer is: CoAP
Q.71 Which type of power converter is used to power an IoT sensor from AC mains?
Inverter
Rectifier
Transformer
Capacitor
Explanation - A rectifier converts AC to DC to supply electronic sensors and controllers.
Correct answer is: Rectifier
Q.72 What is 'edge intelligence' in the context of smart grids?
Storing data at the cloud
Analyzing data locally on devices
Using human operators for decisions
Running large‑scale simulations
Explanation - Edge intelligence processes data near the source, reducing latency and bandwidth.
Correct answer is: Analyzing data locally on devices
Q.73 Which protocol provides secure, encrypted, bidirectional communication between industrial devices and cloud services?
MQTT
HTTP
HTTPS
CoAP
Explanation - MQTT can run over TLS, enabling secure, low‑overhead communication between devices and cloud.
Correct answer is: MQTT
Q.74 What does 'NIST' refer to in the context of IoT security standards?
National Institute of Standards and Technology
National Infrastructure Service Team
New Internet Standards Technology
None of the above
Explanation - NIST provides guidelines and standards for cybersecurity, including IoT device security.
Correct answer is: National Institute of Standards and Technology
Q.75 Which of the following is an example of 'device firmware update (DFU)'?
Changing Wi‑Fi password
Uploading new software to a smart meter
Replacing a battery
Adding a new sensor
Explanation - DFU involves sending updated firmware to a device to patch bugs or add features.
Correct answer is: Uploading new software to a smart meter
Q.76 Which network topology is most resilient to single points of failure?
Star
Mesh
Bus
Ring
Explanation - Mesh networks allow multiple paths between nodes, improving fault tolerance.
Correct answer is: Mesh
Q.77 Which of the following is a typical application of 'blockchain' in smart grids?
Data encryption
Energy trading and settlement
Power generation
Physical security
Explanation - Blockchain provides tamper‑proof records for peer‑to‑peer energy transactions.
Correct answer is: Energy trading and settlement
Q.78 What does 'SCT' stand for in the context of protection relays?
Short‑Circuit Test
Selective Circuit Tripping
Short‑Circuit Trip
Selective Current Transformer
Explanation - SCT is a type of current transformer that isolates and measures current for protection devices.
Correct answer is: Selective Current Transformer
Q.79 Which communication technology is most suitable for high‑data‑rate, low‑latency applications in smart grids?
Zigbee
LTE‑M
LoRaWAN
Bluetooth LE
Explanation - LTE‑M provides cellular connectivity with low latency and moderate bandwidth.
Correct answer is: LTE‑M
Q.80 What is the purpose of 'time‑of‑use' tariffs?
To simplify billing
To charge a flat rate
To encourage off‑peak usage
To eliminate energy usage monitoring
Explanation - Time‑of‑use tariffs vary rates by time of day, incentivizing consumers to shift load.
Correct answer is: To encourage off‑peak usage
Q.81 Which of the following is a benefit of using 'LoRaWAN' for smart grid sensors?
High power consumption
Long range with low power
Requires a wired connection
Low data rate only
Explanation - LoRaWAN provides wide‑area coverage while conserving battery life.
Correct answer is: Long range with low power
Q.82 Which device is used for measuring the total harmonic distortion in an electrical system?
Power analyzer
Voltage transformer
Current transformer
Temperature sensor
Explanation - Power analyzers can assess harmonic distortion by analyzing voltage and current waveforms.
Correct answer is: Power analyzer
Q.83 Which protocol is commonly used for secure communication between SCADA and RTU?
DNP3 over TLS
HTTP
FTP
SNMPv2
Explanation - DNP3 over TLS ensures encrypted, authenticated connections in SCADA‑RTU communication.
Correct answer is: DNP3 over TLS
Q.84 What is 'DDoS' in the context of IoT devices?
Distributed Denial of Service
Direct Data Output System
Digital Device Optimization Service
Dynamic Device Overload System
Explanation - A DDoS attack overwhelms a network or device with traffic, causing it to become unresponsive.
Correct answer is: Distributed Denial of Service
Q.85 Which of the following is a common sensor type used for fault detection in smart grids?
Humidity sensor
Current transformer
Temperature sensor
Vibration sensor
Explanation - Vibration sensors can detect abnormal mechanical conditions, indicating potential faults.
Correct answer is: Vibration sensor
Q.86 Which feature of 'MQTT' ensures that messages are delivered even if the client is offline?
Retained messages
QoS level 0
Persistent session
Last Will and Testament
Explanation - Persistent sessions maintain subscriptions and queued messages for clients that reconnect.
Correct answer is: Persistent session
Q.87 What is the primary benefit of using 'Narrowband IoT' in a smart grid?
Higher data rates
Better support for dense urban deployments
Longer battery life for low‑bandwidth devices
Increased coverage in rural areas
Explanation - Narrowband IoT is optimized for low‑power, low‑data‑rate applications.
Correct answer is: Longer battery life for low‑bandwidth devices
Q.88 Which type of device is a 'gateway' in an IoT smart grid system?
A device that measures voltage
A device that translates between protocols
A device that generates power
A device that stores data locally
Explanation - Gateways bridge communication protocols, enabling different devices to communicate.
Correct answer is: A device that translates between protocols
Q.89 What is the purpose of 'public key infrastructure (PKI)' in smart grid communications?
To simplify key distribution
To provide secure authentication and encryption
To reduce device cost
To eliminate the need for certificates
Explanation - PKI uses certificates and keys to authenticate devices and secure data exchange.
Correct answer is: To provide secure authentication and encryption
Q.90 Which of the following is an example of a 'microgrid'?
A single home battery system
A large regional transmission network
A neighborhood with local generation and storage
A national power grid
Explanation - Microgrids are localized networks that can operate independently of the main grid.
Correct answer is: A neighborhood with local generation and storage
Q.91 What does 'RTU' stand for in power system terminology?
Remote Terminal Unit
Real Time Unit
Registered Transformer Unit
Resistant Temperature Unit
Explanation - An RTU is a field device that collects data and executes control commands.
Correct answer is: Remote Terminal Unit
Q.92 Which of the following best describes 'Zigbee' in IoT?
A high‑speed Wi‑Fi standard
A low‑power, low‑data‑rate mesh network protocol
A proprietary communication protocol for utilities
A physical sensor for measuring voltage
Explanation - Zigbee operates on the IEEE 802.15.4 standard for low‑power communication.
Correct answer is: A low‑power, low‑data‑rate mesh network protocol
Q.93 What is the main function of a 'synchronizer' in a smart grid?
To synchronize clocks across devices
To ensure phase and frequency alignment between sources
To regulate voltage
To store energy
Explanation - Synchronizers maintain coherence among multiple power sources.
Correct answer is: To ensure phase and frequency alignment between sources
Q.94 Which of the following is a typical use of 'edge AI' in smart grids?
Centralized cloud storage
Local real‑time fault detection
Manual human intervention
Generating electricity
Explanation - Edge AI processes data near the source, enabling instant fault identification.
Correct answer is: Local real‑time fault detection
Q.95 What does 'DNP3' stand for in power system communication protocols?
Distributed Network Protocol 3
Digital Network Protocol 3
Data Network Protocol 3
Distributed Network Protocol
Explanation - DNP3 is a protocol for communication between SCADA systems and field devices.
Correct answer is: Distributed Network Protocol
Q.96 Which of the following is a benefit of using 'LoRaWAN' for grid sensor deployment?
High power consumption
Long range and low power usage
Requires wired connections
Low data rate only
Explanation - LoRaWAN offers wide coverage while conserving battery life, suitable for distributed sensors.
Correct answer is: Long range and low power usage
Q.97 Which device is responsible for measuring voltage and current in a smart meter?
Voltage transformer and current transformer
Temperature sensor
Pressure sensor
Humidity sensor
Explanation - Transformers provide scaled, safe signals for accurate measurement.
Correct answer is: Voltage transformer and current transformer
Q.98 What is the purpose of a 'tamper sensor' in smart meters?
To detect unauthorized access
To measure temperature
To monitor voltage
To measure current
Explanation - Tamper sensors trigger alerts when the meter is opened or physically disturbed.
Correct answer is: To detect unauthorized access
Q.99 Which communication protocol uses 'publish/subscribe' messaging for IoT?
HTTP
MQTT
FTP
SMTP
Explanation - MQTT is a lightweight publish/subscribe protocol designed for IoT devices.
Correct answer is: MQTT
Q.100 Which of the following is NOT a typical component of a smart grid?
Smart meters
Microgrid controllers
Water distribution pumps
Demand response systems
Explanation - While important, water pumps are not part of electrical power grid infrastructure.
Correct answer is: Water distribution pumps
Q.101 What does 'NIST' refer to in the context of IoT security?
National Institute of Standards and Technology
Network Integration Security Team
None of the above
Narrowband Internet of Things
Explanation - NIST provides cybersecurity guidelines for IoT device manufacturers.
Correct answer is: National Institute of Standards and Technology
Q.102 Which of the following is a typical use of 'blockchain' in smart grid operations?
Data encryption
Energy trading and settlement
Power generation
Physical security
Explanation - Blockchain ensures tamper‑proof records for peer‑to‑peer energy transactions.
Correct answer is: Energy trading and settlement
Q.103 Which of the following best describes 'mesh networking'?
All devices connect to a single central hub
Each node can relay data for other nodes
Devices communicate only with their immediate neighbor
A wired network topology
Explanation - Mesh networks provide redundancy and extended coverage by allowing data to hop between devices.
Correct answer is: Each node can relay data for other nodes
Q.104 Which sensor measures the rate of energy consumption over time?
Smart meter
Temperature sensor
Current transformer
Voltage transformer
Explanation - A smart meter records energy usage in real time for billing and grid monitoring.
Correct answer is: Smart meter
Q.105 Which device is used to store excess renewable energy for later use?
Transformer
Battery storage unit
Circuit breaker
Voltage regulator
Explanation - Battery storage buffers surplus generation, smoothing supply and demand.
Correct answer is: Battery storage unit
Q.106 What is 'V2G' in smart grid terminology?
Vehicle to Grid
Voltage to Ground
Vehicle to Infrastructure
Voltage to Generator
Explanation - V2G enables electric vehicles to supply power back to the grid.
Correct answer is: Vehicle to Grid
Q.107 Which protocol is typically used for secure, low‑power communication between smart meters and utility servers?
MQTT
CoAP
HTTP
FTP
Explanation - MQTT is lightweight and supports encryption, making it suitable for smart meter data transmission.
Correct answer is: MQTT
Q.108 What is the primary purpose of 'load forecasting' in power systems?
To reduce power generation
To predict future electricity demand
To store excess renewable energy
To shut down the grid during low demand
Explanation - Accurate demand forecasts allow operators to schedule generation efficiently.
Correct answer is: To predict future electricity demand
Q.109 Which IoT protocol can operate over UDP with built‑in reliability features?
CoAP
MQTT
AMQP
HTTPS
Explanation - CoAP is designed for constrained devices, providing reliable transmission over UDP.
Correct answer is: CoAP
Q.110 Which type of device is typically used for real‑time fault detection in distribution circuits?
Current transformer
Voltage transformer
Temperature sensor
Vibration sensor
Explanation - Vibration sensors detect abnormal mechanical vibrations that indicate potential faults.
Correct answer is: Vibration sensor
Q.111 Which security feature is essential for protecting data between IoT devices and the cloud?
Plaintext transmission
TLS encryption
No authentication
Open Wi‑Fi network
Explanation - TLS ensures confidentiality and integrity of data in transit.
Correct answer is: TLS encryption
Q.112 Which of the following best describes 'edge analytics'?
Storing all data in the cloud
Processing data at the source before sending it to the cloud
Manual analysis by engineers
Using only raw data without analysis
Explanation - Edge analytics reduces bandwidth and latency by analyzing data locally.
Correct answer is: Processing data at the source before sending it to the cloud
Q.113 Which protocol is commonly used for device firmware updates in IoT?
HTTP
CoAP
FTP
SMTP
Explanation - CoAP supports efficient OTA updates for constrained devices.
Correct answer is: CoAP
Q.114 Which of the following is NOT a typical component of a smart grid architecture?
Transmission network
Distribution network
Data analytics layer
Consumer kitchen appliances
Explanation - Smart grid architecture focuses on grid infrastructure, not individual household appliances.
Correct answer is: Consumer kitchen appliances
Q.115 Which of the following best describes 'mesh networking'?
All devices connect to a single central hub
Each node can relay data for other nodes
Devices communicate only with their immediate neighbor
A wired network topology
Explanation - Mesh networks provide redundancy and extended coverage by allowing data to hop between devices.
Correct answer is: Each node can relay data for other nodes