Unit 3: IoT-Design Requirements - Practice Quiz

1 What is the main purpose of a message communication protocol in IoT?

2 Which protocol is widely used for lightweight publish-subscribe messaging in IoT?

3 In a publish-subscribe model, which component receives messages based on a topic?

4 What type of communication does WebSocket support after a connection is established?

5 WebSocket is especially useful when an IoT application needs what?

6 Which is a common IoT design requirement for battery-powered devices?

7 Which issue is a major challenge in large IoT systems?

8 Which is an example of an IoT application?

9 How can IoT be used in agriculture?

10 What is the primary role of a sensor in an IoT device?

11 Which sensor is commonly used to detect temperature?

12 What is the main role of an antenna in a wireless IoT device?

13 Why is cloud computing useful for IoT systems?

14 What can an IoT device send to a cloud platform?

15 What does SaaS stand for?

16 In a SaaS model, who usually manages the application software?

17 What does PaaS provide to application developers?

18 What does IaaS primarily provide?

19 Which practice helps protect an IoT device from unauthorized access?

20 Why are software updates important for IoT security?

21 A battery-powered sensor sends a small temperature reading every 10 minutes over an unreliable network. Which protocol characteristic is most important for reducing device overhead?

22 In a publish-subscribe IoT system, what is the main role of a message broker?

23 A smart-building system must ensure that a critical alarm message reaches the monitoring server even if the first transmission fails. Which communication feature is most suitable?

24 Why is WebSocket suitable for a dashboard that must show live updates from connected devices?

25 A web client receives sensor alerts immediately without repeatedly polling a server. Which WebSocket behavior enables this?

26 A city deploys thousands of parking sensors that must continue working as more zones are added. Which IoT design requirement is being addressed?

27 An industrial IoT controller must react to an overheating event within 50 ms. Which requirement is most critical?

28 Devices from different vendors cannot exchange data because each uses an incompatible data format. This is primarily an issue of:

29 Which application best represents predictive maintenance in an IoT environment?

30 A smart irrigation system combines soil-moisture readings with weather forecasts before opening valves. What IoT service is mainly being used?

31 A cold-storage monitor must measure the physical quantity that indicates whether stored medicine remains within a safe range. Which sensor is required?

32 An IoT device has poor wireless range after being placed inside a metal enclosure. Which component should be reviewed first?

33 A motion-activated security light should detect the presence of people without requiring them to touch a device. Which sensor is most appropriate?

34 Why is cloud computing commonly used with IoT systems that generate large volumes of sensor data?

35 An edge gateway filters raw camera data locally and sends only detected events to the cloud. What is the primary benefit?

36 A company uses a browser-based IoT dashboard provided by a vendor and does not manage its servers or application updates. This is an example of:

37 A development team wants to build a custom IoT analytics application but does not want to manage operating systems, runtime installation, or server patching. Which cloud model fits best?

38 An organization needs virtual machines for an IoT data-processing system and wants control over the operating system and installed software. Which model should it choose?

39 A smart camera still uses the manufacturer's default administrator password after installation. Which risk is most directly increased?

40 A device sends health-monitoring data to a cloud platform over a public Wi-Fi network. Which control best protects the data while it is being transmitted?

41 A battery-powered sensor publishes QoS 1 messages through MQTT and may disconnect immediately after receiving a PUBACK. Which conclusion about delivery to the application subscriber is correct?

42 A constrained device uses CoAP confirmable requests through a proxy. After a timeout, it retransmits the same request. Which design best prevents a non-idempotent operation from executing twice?

43 A browser opens a secure WebSocket connection through an HTTP reverse proxy. The initial handshake succeeds, but bidirectional frames fail immediately afterward. Which proxy behavior is the most likely cause?

44 Ten thousand IoT dashboards maintain WebSocket connections to a clustered backend. Clients currently depend on process-local subscription state. Which change most directly enables reliable horizontal scaling without mandatory sticky sessions?

45 A remote actuator must enter a safe state within 50 ms when hazardous vibration is detected, even during a WAN outage. Which architecture best satisfies the requirement?

46 A deployment grows from to devices, and each device sends one 200-byte reading every 10 seconds. Ignoring protocol overhead, what sustained ingress throughput is required?

47 A predictive-maintenance service combines vibration, temperature, and maintenance records. Sensor clocks can drift by several seconds. Which processing strategy best preserves the meaning of cross-sensor correlations?

48 A smart-meter billing service receives duplicate and out-of-order readings because devices retry transmissions. Which data model most reliably prevents double billing while preserving auditability?

49 An IoT node transmits 14 dBm. Cable loss is 2 dB, transmit-antenna gain is 3 dBi, free-space path loss is 100 dB, receive-antenna gain is 2 dBi, and receiver sensitivity is dBm. What is the link margin?

50 A quarter-wave antenna is designed for 915 MHz in free space. Using m/s, what is its approximate physical length before accounting for material and end effects?

51 A cloud IoT pipeline accepts telemetry through an at-least-once broker. Autoscaled consumers may crash after writing data but before acknowledging messages. Which storage operation best preserves correctness?

52 An IoT analytics system experiences unpredictable bursts but must retain every event while scaling consumers gradually. Which cloud design most effectively absorbs the bursts?

53 A multi-tenant SaaS dashboard queries a shared telemetry database. Which control most directly prevents a valid user from reading another tenant's device data through a modified API request?

54 An IoT SaaS vendor deploys a schema change while customer devices and API clients upgrade over several weeks. Which release strategy best preserves service continuity?

55 A team uses a managed IoT application platform that supplies device registries, message routing, runtime scaling, and managed databases. Which responsibility normally remains with the application team under PaaS?

56 An IoT application on a PaaS must perform a 20-minute firmware-signing job, but request handlers have a 60-second execution limit. Which redesign best fits the platform model?

57 An organization runs its IoT broker on IaaS virtual machines. The cloud provider patches the hypervisor, but a broker VM is compromised through an outdated operating-system package. Who was primarily responsible for that patch?

58 A stateful MQTT broker cluster runs on IaaS across three availability zones. Which design best limits message loss during a single-zone failure?

59 A captured IoT command is encrypted and authenticated with a valid device key. An attacker retransmits it later, causing the actuator to repeat the action. Which additional mechanism most directly blocks this attack?

60 A manufacturer discovers that a signing key used for IoT firmware updates has been compromised. Devices enforce secure boot and accept only signed images. Which prior design most effectively supports recovery without physically recalling every device?