Exam MB-400: Microsoft Power Apps + Dynamics 365 Developer Practice Test
Exam MB-400 practice focuses on developing business applications with Power Apps and Dataverse. The question bank samples tasks involving model-driven and canvas apps, row relationships, form logic, security privileges, calculated columns, and integrations. It also touches on Power Fx references, environment-specific configuration, and extending Dataverse with custom APIs and server-side behavior.
Exam overview
About the Exam MB-400: Microsoft Power Apps + Dynamics 365 Developer Exam
The practice topics reflect decisions developers make when shaping Dataverse data and application behavior. Relationship settings affect whether a row can be deleted while related records exist; security privileges distinguish viewing a row from changing it. App-building scenarios include choosing a canvas form for coordinated data entry and using a business process flow to guide users through record stages. Other questions cover selecting client-side logic for straightforward validation, calculating values that must be stored on a Dataverse row, and using the platform's REST interface for HTTP-based integration. Power Fx column references and environment variables appear in contexts where names may be ambiguous or configuration differs between deployments. Custom API scenarios point to implementing named business operations on the server. Together, these subjects exercise feature selection and practical reasoning across app, data, integration, and extension work.
Sample Practice Questions
Review a selection from this exam's published US Practice Tests practice bank.
A developer needs to prevent a Dataverse row from being deleted when it is referenced by another row. Which relationship behavior is most appropriate?
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Correct answer: BA restrict-delete relationship behavior blocks deletion of the referenced row while dependent rows still refer to it. Cascade delete would instead delete related rows.
A canvas app must let a user enter several fields for a new Dataverse row and submit them together using a standard form pattern. Which control is designed for this task?
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Correct answer: AAn Edit form can be configured for new-row entry, connected to a data source, and submitted with the form submission pattern. The other controls do not provide a standard data-entry form.
A maker wants to create a guided sequence of stages for users to follow while working on a model-driven app record. Which feature is intended for this purpose?
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Correct answer: AA business process flow presents stages and steps that guide users through a defined business process on a model-driven app record.
A developer needs a Dataverse customization that validates a value whenever a user edits a row, without writing server-side code. Which option is generally suitable for straightforward field and form logic?
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Correct answer: ABusiness rules provide configurable logic for validation and actions such as setting or requiring values, without requiring custom server-side code. Plug-ins and custom APIs are code-based extensibility options for more advanced requirements.
A Dataverse integration must send requests to the service using the platform's REST interface and standard HTTP methods. Which interface is intended for this purpose?
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Correct answer: AThe Dataverse Web API is the RESTful interface used by clients and integrations to interact with Dataverse through HTTP requests. The other choices are maker or app configuration tools.
A solution needs a setting that differs between development and production, such as an endpoint URL, without changing the solution's implementation. Which Dataverse feature is intended to hold that value?
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Correct answer: AEnvironment variables let solution-aware apps and flows use configuration values that can be supplied or changed for each environment. Business units organize security, rollup columns aggregate related data, and activity parties represent participants in activities.
A developer wants to expose a Dataverse operation through a custom API so that clients can invoke named business logic. Which implementation is commonly associated with the custom API's server-side behavior?
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Correct answer: AA Dataverse custom API can be associated with a plug-in type that implements its server-side operation. UI components and form elements do not implement the API's server-side behavior.
How to use this practice test
Access is free. Each session presents up to 20 random questions from the 50-question MB-400 practice bank, with results shown after the session. Use the questions to check how well you distinguish Dataverse features and choose app or integration patterns for a stated requirement; revisit any missed concept before trying another session.
Preparation tips
- Compare Dataverse relationship behaviors and trace how each affects deleting a parent row with related records.
- Practice mapping user needs to canvas forms, model-driven app business process flows, and client-side validation options.
- Write Power Fx expressions that reference Dataverse columns clearly, especially when display names contain spaces or resemble control names.
- Review how Dataverse security privileges, calculated columns, and environment variables affect row access, stored values, and deployment configuration.
- Trace a REST integration request and distinguish the custom API operation from its server-side implementation.