Exam AZ-220: Microsoft Azure IoT Developer Practice Test
Exam AZ-220 concerns developing Azure-based Internet of Things solutions, including device connectivity, cloud-to-device communication, and edge workloads. Relevant work spans connecting devices securely to IoT Hub, managing device identities and metadata, routing events to applications, and configuring IoT Edge modules. Practice topics also involve MQTT communication patterns, message properties, and authentication with symmetric keys.
Exam overview
About the Exam AZ-220: Microsoft Azure IoT Developer Exam
IoT development requires selecting communication and management mechanisms that fit device behavior and application needs. Device twins separate centrally managed desired configuration and reported state from device application code, while the device registry supports identity and metadata management. IoT Hub message properties distinguish system-managed fields from application-defined values, such as correlation identifiers. Event-driven integration can deliver lifecycle or registry-change notifications to handlers without continuous polling. For edge deployments, developers package modules and configure deployments so workloads can run on gateways; modules can read centrally managed settings without rebuilding images. Secure connectivity involves using the provisioned credential to create authentication tokens and validating the service identity during TLS connections. MQTT clients also need the appropriate IoT Hub topic pattern for cloud-to-device subscriptions. These decisions connect device-side implementation with cloud management and operational response.
Sample Practice Questions
Review a selection from this exam's published US Practice Tests practice bank.
A team wants to run a containerized edge module on a gateway and manage its deployment and configuration from Azure. Which technology is intended for this purpose?
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Correct answer: AAzure IoT Edge extends cloud-managed IoT workloads to edge devices, where containerized modules can run locally and be deployed and managed remotely. The other services serve different application or data-integration roles.
An IoT solution needs to store device metadata such as a device's location so that it can be queried and updated independently of device code. Which IoT Hub feature is designed for this purpose?
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Correct answer: ADevice twins are JSON documents that represent device state and metadata. Their tags are intended for backend use, while desired and reported properties support configuration and state synchronization.
A fleet-management service needs to identify devices that have not communicated recently and then investigate their status. Which information is most useful to query for this purpose?
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Correct answer: AThe device identity registry exposes last activity information that can help identify devices that have not communicated recently. The other choices do not indicate when a device last communicated with the hub.
A device sends a telemetry message with a correlation identifier. Which IoT Hub message property category should it use for this application-defined value?
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Correct answer: BApplication properties are user-defined key-value pairs that travel with a message and can be used by downstream applications or routing rules. System properties are reserved for protocol and service-defined metadata.
An IoT Edge module needs to read configuration values that are managed centrally and changed without rebuilding its container image. Where should the module obtain its deployment configuration?
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Correct answer: AModule twins provide cloud-managed desired properties and module-reported state. A module can watch desired-property updates and apply configuration changes independently of its container image.
A device is provisioned to IoT Hub using a symmetric key and needs to create an authentication token for a connection. Which credential is used to sign the token?
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Correct answer: AFor symmetric-key authentication, the device uses its key to generate a shared access signature token, which proves possession of the credential. The event endpoint and twin properties are not authentication secrets.
A device uses MQTT to connect to IoT Hub and needs to subscribe to receive cloud-to-device messages. Which topic pattern is used for that subscription?
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Correct answer: AFor MQTT connections, a device subscribes to the device-bound topic pattern `devices/{device-id}/messages/devicebound/#` to receive cloud-to-device messages, including relevant topic properties.
How to use this practice test
The free AZ-220 practice bank contains 50 published questions. Start a session with up to 20 randomly selected questions, then use the displayed results to identify areas to revisit, such as device identity, MQTT messaging, event handling, or IoT Edge configuration.
Preparation tips
- Trace how a device identity, symmetric-key credential, and signed authentication token relate during an IoT Hub connection.
- Compare device twins with device registry metadata; identify which holds desired or reported configuration and which supports identity-related records.
- Practice distinguishing system properties from application properties when examining IoT Hub messages and correlation identifiers.
- Map IoT Hub lifecycle and registry-change events to event-driven handling, and contrast that approach with repeated polling.
- Review IoT Edge deployment configuration and MQTT cloud-to-device subscription patterns, including how each is used by a gateway or device client.