Introduction

Prepare for your Power BI interviews with these top questions and clear, concise answers. This guide covers Power BI basics, DAX, data modeling, visualization, and real-world troubleshooting, ideal for freshers and experienced candidates.

Power BI Interview Questions and Answers

1. What is Power BI?
A Microsoft business analytics tool for visualizing data and sharing insights.

2. What are the key components of Power BI?
Power BI Desktop, Power BI Service, Power BI Mobile, Power BI Gateway, and Power BI Report Server.

3. What is DAX in Power BI?
Data Analysis Expressions, a formula language for calculations in Power BI.

4. Explain the difference between Power BI Desktop and Power BI Service.
Desktop is for creating reports; Service is for sharing and collaboration.

5. What data sources can Power BI connect to?
Excel, SQL Server, Azure, web data, and many more.

6. What is Power Query?
A data connection technology for data transformation and preparation in Power BI.

7. What is the use of relationships in Power BI?
To connect tables logically for building data models.

8. What is a calculated column?
A new column created using DAX formulas within Power BI tables.

9. What is a measure in Power BI?
A DAX calculation used in data analysis that computes results on the fly.

10. What is the difference between a calculated column and a measure?
Calculated columns are computed during data refresh; measures are calculated during report interaction.

11. Explain the use of slicers in Power BI.
Visual filters for users to slice and filter report data interactively.

12. What is the Power BI Gateway?
A bridge to connect on-premises data securely with Power BI Service.

13. How do you refresh data in Power BI?
Manually or by scheduling automatic refresh in Power BI Service.

14. What is Power BI Report Server?
An on-premises report server for hosting Power BI reports within an organization.

15. What is drill-through in Power BI?
Allows users to navigate to a detailed page by right-clicking data points.

16. What is drill-down in Power BI?
Allows exploring data from higher to lower levels in a hierarchy.

17. Explain the term KPI in Power BI.
Key Performance Indicator, used for visualizing progress against targets.

18. What are bookmarks in Power BI?
Used to capture the current state of a report page for navigation and storytelling.

19. What is a custom visual in Power BI?
Visuals created by developers or from AppSource to extend Power BI capabilities.

20. How to improve Power BI report performance?
Optimize data models, reduce visuals, use measures instead of calculated columns, and limit imported data.

21. What is the Power BI Service URL?
https://app.powerbi.com

22. What is row-level security (RLS) in Power BI?
Restricts data access for specific users based on filters.

23. What are filters in Power BI?
Used to restrict and refine data displayed in visuals and reports.

24. Explain star schema in Power BI.
A data modeling approach with a central fact table linked to dimension tables.

25. What is Q&A in Power BI?
Natural language query feature allowing users to ask questions about data.

26. What file formats does Power BI support for data import?
Excel, CSV, XML, JSON, and direct database connections.

27. What is the difference between Import and DirectQuery in Power BI?
Import loads data into Power BI; DirectQuery queries data live from the source.

28. What is the Power BI mobile app used for?
Viewing and interacting with reports and dashboards on mobile devices.

29. What is a dashboard in Power BI?
A single-page view of visuals created from different datasets and reports.

30. What is the significance of DAX in Power BI?
Used for building advanced calculations, time intelligence, and dynamic analysis.

31. How to handle errors in Power Query?
Using error handling steps, removing errors, or replacing error values.

32. What is a dataflow in Power BI?
Reusable data preparation layer using Power Query in Power BI Service.

33. How do you create a hierarchy in Power BI?
Drag and drop fields within visuals to define hierarchical levels.

34. What are themes in Power BI?
Custom color schemes to apply consistent styling across reports.

35. What is drillthrough filter?
Filters applied to drillthrough pages for detailed analysis.

36. How to share Power BI reports?
Via Power BI Service using sharing options or publishing to workspaces.

37. What is ALM Toolkit for Power BI?
A tool for managing and deploying Power BI datasets.

38. What are incremental data loads in Power BI?
Loading only new or changed data instead of entire datasets during refresh.

39. What is paginated report in Power BI?
Printable reports with precise layouts for printing or PDF exports.

40. How to connect Power BI to SQL Server?
Using the SQL Server connector in Power BI Desktop.

41. What is composite model in Power BI?
Combining Import and DirectQuery data sources in a single model.

42. What is data modeling in Power BI?
The process of creating relationships, measures, and hierarchies to analyze data.

43. What are quick measures in Power BI?
Predefined calculations created without writing DAX manually.

44. What is conditional formatting in Power BI?
Applying formatting based on data values in visuals.

45. What is a tooltip in Power BI?
Information displayed when hovering over data points in visuals.

46. What is the use of the CALCULATE function in DAX?
Modifies filter context to perform complex calculations.

47. What is Power BI Embedded?
Embedding Power BI visuals into applications using APIs.

48. What is the function of ALL() in DAX?
Removes filters to return all rows in a table or column.

49. What is the RELATED function in DAX?
Fetches a related value from another table using relationships.

50. What is the purpose of the SUMX function in DAX?
Performs row-wise calculations and then sums the results.

Frequently Asked Questions