Unit 6: IoT Cloud & Edge Integration - Practice Quiz

1 Which layer of a basic IoT architecture contains sensors and actuators?

2 What is the main purpose of the network layer in an IoT architecture?

3 Which communication model is used by MQTT?

4 What is the role of an MQTT broker?

5 What does HTTP stand for?

6 Which HTTP method is commonly used to retrieve data from a server?

7 CoAP is mainly designed for which type of device?

8 Which transport protocol is commonly used by CoAP?

9 What is ThingSpeak commonly used for in IoT projects?

10 Which AWS service connects IoT devices securely to the AWS cloud?

11 Which protocol is directly supported by AWS IoT Core for lightweight publish-subscribe messaging?

12 What is the primary purpose of Azure IoT Hub?

13 Which company provides Azure IoT Hub?

14 In a REST API, what does an endpoint usually represent?

15 Which data format is commonly exchanged through REST APIs?

16 What is the main purpose of a real-time IoT dashboard?

17 Where does edge computing process IoT data?

18 What is one common benefit of edge computing compared with cloud-only computing?

19 What does OTA stand for in IoT firmware updates?

20 What is a key advantage of OTA firmware updates?

21 A smart irrigation system must continue controlling water valves when its internet connection fails. Which architecture best satisfies this requirement?

22 A factory has hundreds of sensors using Zigbee, but its cloud service accepts only IP-based traffic. Which component should translate and forward the sensor data?

23 A temperature sensor publishes to building/room1/temperature, and several applications must receive each new reading. Which MQTT feature enables this behavior?

24 An alarm message must reach the cloud at least once, but occasional duplicate delivery is acceptable. Which MQTT QoS level should be selected?

25 A dashboard should immediately show the most recently published device status when it subscribes, even if the device has not sent a new message. What should the publisher use?

26 A battery-powered sensor wakes every minute, sends one reading using HTTP, and disconnects. What is the main disadvantage compared with MQTT?

27 A device submits a new telemetry record to /api/readings. Which HTTP method is most appropriate when the server assigns the record identifier?

28 A constrained sensor network uses lossy links and requires lightweight request-response communication. Why is CoAP suitable for this environment?

29 A CoAP client sends a critical actuator command over an unreliable network and needs acknowledgment-based retransmission. Which message type should it use?

30 A weather station sends temperature, humidity, and pressure to one ThingSpeak channel. What is the most appropriate data organization?

31 A public ThingSpeak channel accepts sensor updates only from authorized devices. Which credential should a device include when writing data?

32 An application must display the latest reported state of an intermittently connected device. Which AWS IoT Core feature is designed for this purpose?

33 Sensor messages arriving at AWS IoT Core must be stored in DynamoDB without modifying the device firmware. Which feature should route the messages?

34 A cloud application sends a desired fan speed to an offline device. The device should retrieve the value when it reconnects. Which Azure IoT Hub capability is most appropriate?

35 An operator must request an immediate diagnostic action from a connected device and receive a result. Which Azure IoT Hub feature best fits this interaction?

36 A client sends the same complete configuration to /devices/42/config several times, and the final server state should remain unchanged after the first successful request. Which HTTP method best expresses this idempotent update?

37 An IoT application receives HTTP status code 429 while uploading telemetry through a REST API. What should the application do?

38 A dashboard plots a sensor that reports once per second, but the chart redraws only once per minute. Which change most directly improves the dashboard's apparent real-time behavior?

39 A camera system must stop a machine within 50 ms after detecting a safety hazard, while long-term video analytics can tolerate several seconds. Where should each workload run?

40 A device loses power while installing an OTA firmware update. Which design most effectively allows it to recover without becoming unusable?

41 A battery-powered vibration sensor must detect bearing faults within 200 ms, continue operating during intermittent Internet outages, and support fleet-wide analytics. Which architecture best satisfies all three requirements?

42 An MQTT client publishes telemetry with QoS 1 and receives a PUBACK, but the application processes the message twice after a reconnect. Which design correctly addresses this behavior?

43 A device must receive commands while it is offline, but stale commands must not be delivered when it reconnects. Which MQTT configuration is most appropriate?

44 A device sends a measurement using an HTTP POST request. The request times out, and the device cannot determine whether the server stored the measurement. Which server-side mechanism most directly prevents duplicate records after a retry?

45 A constrained gateway exposes a resource whose representation changes frequently. Clients should avoid downloading unchanged content, while the gateway must remain compatible with standard HTTP caching. Which approach is best?

46 A low-power sensor sends a confirmable CoAP POST through an unreliable network. It receives no acknowledgment after the retransmission limit is reached. What is the correct application-level conclusion?

47 A CoAP resource must be updated reliably, and repeating the operation after a lost response must not create an additional logical effect. Which method and design are most suitable?

48 A ThingSpeak channel receives measurements from several devices, but the analysis must distinguish devices and preserve a consistent schema. Which design is most appropriate within a single channel?

49 A device posts to ThingSpeak every second, but the channel has an update interval restriction that is longer than one second. What is the most robust device-side strategy?

50 An AWS IoT device policy should allow a device to publish only to its own telemetry topic and subscribe only to commands addressed to that same device. Which policy principle is essential?

51 A fleet uses AWS IoT Device Shadow documents. A device reconnects after being offline and reports a desired state version older than the cloud version. Which behavior best prevents stale state from overwriting newer state?

52 An Azure IoT Hub solution must route temperature messages to different storage systems based on a device-reported site identifier. Which feature is designed for this requirement?

53 A device is temporarily offline when a cloud service invokes an operational command. The command must be executed only once and must report a result tied to the request. Which mechanism is most suitable?

54 A REST endpoint updates an actuator configuration containing a version number. Two clients read version 10 and then submit conflicting changes. Which API design prevents the second update from silently overwriting the first?

55 An IoT platform exposes a paginated REST endpoint, and records can arrive while a client is synchronizing. Which approach most reliably avoids missing or duplicating records?

56 A dashboard plots sensor data arriving through multiple gateways whose clocks are not synchronized. Which visualization strategy best avoids false causal ordering?

57 A real-time dashboard must remain responsive when ingesting 50,000 points per second while users inspect one-minute trends. Which architecture is most appropriate?

58 A safety controller must stop an industrial motor within 50 ms even when the wide-area network is unavailable, while historical optimization can tolerate several minutes of delay. Where should each workload execute?

59 An edge gateway performs anomaly detection locally and sends only alerts to the cloud. Which additional design is most important for maintaining trustworthy fleet-wide analytics?

60 A firmware update may be interrupted by power loss, and a failed image must not permanently disable the device. Which update design provides the strongest protection?