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WorksheetsIoT Situational-Based MCQs - Basic to intermediate
Total questions: 40
Worksheet time: 20mins
A home automation IoT system stops responding to user commands from a mobile app. What should be checked first?
Cloud storage configuration
Device power supply and Wi-Fi connectivity
User interface design
Microcontroller pin mapping
You're designing a temperature sensor node for agriculture. What’s the most power-efficient communication protocol to use?
Bluetooth Classic
Zigbee
Wi-Fi
LoRa
Your ESP32-based IoT device overheats after prolonged operation. What’s a possible cause?
Using battery instead of adapter
Excessive Wi-Fi transmission intervals
OLED display resolution
I2C bus delay
You need to deploy multiple IoT sensors in a large field. Which network topology suits best?
Star topology with Wi-Fi
Point-to-point with BLE
Mesh topology with Zigbee
Ring topology with UART
A motion sensor sends data to cloud every 1 second. What issue may occur?
Low sensitivity
Data loss due to bandwidth limitation
Longer sleep mode
Temperature drift
A user wants to monitor their smart water meter remotely. Which architecture component handles remote access?
Actuator
Cloud server
Local storage
MQTT broker
You’ve implemented MQTT protocol. What does the “broker” do?
Stores data logs
Routes messages between publishers and subscribers
Converts analog signals
Encrypts Wi-Fi
Which sensor is best suited to detect gas leakage in a smart kitchen system?
DHT11
BMP180
MQ-2
LDR
A smart irrigation system fails to activate at scheduled time. What’s the likely cause?
Moisture sensor broken
Timer service not implemented properly
Cloud storage failure
Wrong soil type
You’re testing your IoT prototype but getting inconsistent sensor data. What’s your first debugging step?
Increase Wi-Fi range
Check sensor wiring and calibration
Change cloud provider
Adjust MQTT topic
Your IoT node fails to wake up from deep sleep. What’s the possible design issue?
Flash memory not initialized
Wake-up pin not configured properly
Too short delay loop
Large sensor data
A smart door system should open only for registered users. Which component ensures this?
Proximity sensor
Relay
Authentication server
MQTT
Which of the following is NOT a feature of typical IoT devices?
Real-time monitoring
High GPU performance
Low power consumption
Remote access
A user cannot connect to the smart home device from their phone. What should be verified first?
USB cable
Mobile app font size
Wi-Fi SSID and password settings
EEPROM write cycles
You are asked to log data every minute in an IoT device with limited memory. What’s an efficient method?
Save every data point permanently
Use ring buffer or FIFO storage
Use JSON for storage
Reboot the device
You want your IoT node to function with solar power. What’s the priority in design?
High RAM
Low-power components and sleep modes
OLED display
Frequent data transmission
In your IoT design, you wish to reduce latency. Which protocol is best?
FTP
SMTP
HTTP
MQTT
Your weather station shows -1°C despite a hot environment. What’s most likely the issue?
Overheating microcontroller
Cloud sync delay
Sensor failure or miscalibration
Weak Wi-Fi
You are building an IoT system to track delivery vehicles. Which module is essential?
DHT11
GPS module
RTC
Potentiometer
A smart lock opens whenever nearby BLE devices connect. What’s the major concern?
Security vulnerability due to lack of authentication
Bluetooth version mismatch
High battery life
EEPROM overflow
Your IoT air quality monitoring system shows delayed updates on the dashboard. What's a practical optimization?
Replace CO2 sensor
Reduce sampling interval and use local processing
Increase dashboard font size
Use HTTP instead of MQTT
In a smart traffic system, the MQTT broker crashes under high load. What architecture improvement can you use?
Move to BLE communication
Implement broker clustering or load balancing
Remove QoS settings
Use SMS-based alerts
You want to update firmware on 500 deployed IoT devices remotely. Which method is ideal?
Reflash locally via USB
Use OTA (Over-the-Air) updates with checksum validation
Send code via email
Use serial monitor remotely
Your IoT sensor node is located far from Wi-Fi range and needs long-range transmission. What should you choose?
Bluetooth
Zigbee
LoRaWAN
UART
In a wearable health tracker, the battery depletes too quickly. What’s a good optimization?
Use Li-Ion battery only
Use sleep modes and reduce sampling frequency
Increase sampling rate
Display sensor logs in real time
Your IoT dashboard shows duplicate entries from the same sensor. What is a probable root cause?
GPS error
MQTT client re-publishing on reconnect without session persistence
Sensor heating
Real-time clock fault
Your agricultural IoT node occasionally crashes due to insufficient memory. Which technique improves reliability?
Use more sensors
Enable garbage collection and data aggregation before upload
Increase Wi-Fi power
Reduce PCB size
What’s the best way to maintain security in a consumer IoT product?
Hard-code passwords
Use encrypted communication and secure boot
Avoid firmware updates
Disable sleep mode
You observe inconsistent readings from your capacitive soil moisture sensor. What’s the best solution?
Add pull-up resistor
Calibrate readings in software based on multiple samples
Disable ADC
Change Wi-Fi frequency
Which data format is most efficient for transmitting sensor values to cloud?
CSV
XML
JSON
TXT
An IoT device must trigger an alarm when temperature crosses 60°C. What’s the best implementation strategy?
Poll temperature continuously
Use interrupt-based threshold alert
Delay and check temperature every 10 seconds
Restart sensor
Your IoT application sends image snapshots occasionally. What is an efficient communication approach?
Send over BLE
Use FTP over TCP
Encode image in base64 and send via MQTT
Use plain UART
A developer chooses UDP for IoT data transmission. What's a valid reason?
High reliability
Low latency and less overhead
Encryption by default
Requires fewer servers
What is the main role of a gateway in an IoT ecosystem?
Increase battery life
Route sensor data from edge devices to cloud securely
Store firmware
Recharge IoT devices
A cloud-hosted database frequently becomes inaccessible due to spikes in IoT uploads. What should be done?
Increase sampling rate
Buffer data locally and implement retries
Remove data logger
Reduce Wi-Fi signal
Your BLE-based IoT tracker frequently disconnects when in motion. What’s a likely cause?
Sensor overvoltage
Signal interference or antenna placement
Data overload
Board thickness
What’s the role of an edge device in IoT?
Display user interface
Perform local computation and reduce cloud load
Send bulk data to mobile apps
Encrypt Wi-Fi signal
You wish to save power in a remote sensing IoT device. What is an effective strategy?
Keep Wi-Fi always ON
Schedule data uploads in bursts and use deep sleep between
Use high baud rate
Disable brownout detection
What security flaw could occur if MQTT credentials are stored in plain text on the device?
Faster connection time
Easy access for attackers if compromised
Improved latency
Reduced data packet size
An industrial IoT system requires high reliability and guaranteed delivery of messages. Which MQTT QoS level should be used?
QoS 0 – At most once
QoS 1 – At least once
QoS 2 – Exactly once
QoS 3 – Broadcast
