Power BI Important Concepts Interview Questions & Answers

By


Power BI Important Concepts Interview Questions & Answers (2026 Guide)

Power BI Important Concepts Interview Questions & Answers


If you're preparing for Power BI interviews, learning Power BI DAX, building interactive dashboards, or working on business intelligence reporting, this complete guide covers all the essential Power BI concepts in a structured Q&A format.


Let’s dive into the most important Power BI interview questions and answers.

Q1. What are the components of Power BI?

Ans. There are five different components of Power BI:

Power Pivot: Fetches and cleans data and loads it onto Power Query.

Power Query: Operates on the loaded data.

Power Q&A: Makes it possible for users to interact with reports using simple English language.

Power View: This lets users create interactive charts, graphs, maps, and other visuals.

Power Map: Enables the processing of accurate geographic locations in datasets.

Q2. How is Power BI different from Tableau?

Ans. Below are some of the major differences between Power BI and Tableau:

Pricing: Power BI is generally less expensive than Tableau, especially for larger teams.

Ease of use: Power BI is generally easier to use, especially for those who are already familiar with Microsoft products. Tableau has a more robust feature set.

Data sources: Both can connect to a wide range of data sources. However, Tableau has more advanced features for connecting to and preparing data.

Visualisations: Both offer a wide range of options. Some feel Tableau offers more flexibility/customisation, while others prefer the simplicity of Power BI.

Q3. How is Power BI different from other BI tools?

Ans. Power BI provides better features and data manipulation tools compared to tools like Tableau. A single user can connect with multiple data sources without experience in coding. It is closely integrated with Microsoft tools such as Office 365, SharePoint, and Bing. In the free version of Power BI Desktop, users can analyse datasets up to 1GB with 10,000 rows of data streaming every hour.

Q4. What is the DAX Function?

Ans. It is a formula expression language called Data Analysis Expressions (DAX). It is a functional language where the full code is kept inside a function. Data types of DAX are: 1) Numeric, 2) Boolean, 3) DateTime, 4) String, and 5) Decimal.

Q5. What are the types of filters available in Power BI Reports?

Ans. Important filters are:

Visual-level Filters
Page-level Filters
Report-level Filters

Q6. Differentiate between Power BI and Excel.

Ans. The key differences are:

Tabular reports: Excel is better at handling tabular reports; Power BI is not as strong here.

Duplicate table: Excel allows duplicate tables; Power BI cannot display them.

Reports: Power BI allows interactive, personalized reports and cross-filtering; Excel lacks advanced cross-filtering.

Analytics: Power BI offers simple analytics; Excel offers advanced analytics.

Applications: Power BI is ideal for KPIs and dashboards. Excel charts cannot connect to a data model in the same way.

Q7. What is the CALCULATE function in DAX?

Ans. The CALCULATE function helps calculate the sum of an entire column and can be modified using filters.

Syntax:
CALCULATE(<expression>[, <filter1> [, <filter2> [, ...]]])

Q8. What are the different challenges faced by a Power BI developer?

Ans. Challenges include:

Power BI does not have a feature for data cleansing.
Problems with very large datasets.
Performance issues (observed issues with more than 20,000–30,000 rows in some queries).
Bulky user interface.

Q9. How can you do automation in Power BI?

Ans. Automation can be done with Power Automate, a cloud-based service that allows you to create workflows to automate business processes with over 200 connectors.

Q10. Can you explain the bookmark function of Power BI?

Ans. It captures a configured view of a report's current state (including slicers and filters) so you can return to it or use it for storytelling.

Q11. Explain the major concept of Power BI.

Ans. Power BI is a cloud-based, self-service business intelligence solution used for data sharing, reporting, and dashboards. It is user-friendly, works with multiple data sources, and offers on-premise, web, and mobile platforms.

Q12. What is Power BI Desktop?

Ans. A free Microsoft Windows desktop application used to import, cleanse, design, and model data. It works in association with the Power BI Service.

Q13. What is Get Data in Power BI?

Ans. A feature on the Menu bar that offers connectivity to numerous data sources like Excel, Azure SQL, Facebook, Google Analytics, etc.

Q14. What are the building blocks of Power BI?

Ans. The five key components/building blocks are:

Visualizations
Datasets
Reports
Dashboards
Tiles

Q15. What are the visualisations in Power BI?

Ans. They are visual representations of data. Examples include Bar charts, Column charts, Line charts, Pie charts, Waterfall charts, and custom visuals from the library.


Q16. What are reports in Power BI?

Ans. A report is a combination and collection of different visualisations relevant to a particular business topic, organised in a structured way.

Q17. What do you understand by dashboards in Power BI?

Ans. A dashboard is a single-page canvas that uses visualisations to tell a story or provide quick insights for decision-making.

Q18. What are the KPIs in Power BI?

Ans. Key Performance Indicators evaluate an organisation's performance against measurable goals. A KPI has a base value evaluated against a target value.

Q19. How many versions of Power BI are available as of now?

Ans.

  • Power BI Desktop: Free tool for development and authoring.
  • Power BI Pro: Self-service BI for collaboration and sharing ($9.99/user/month).
  • Power BI Premium: Enterprise solution for big data support and dedicated cloud storage ($20/user/month).

Q20. What are Slicers in Power BI?

Ans. Slicers are visual filters present on the report page that allow users to sort and filter information (e.g., selecting a specific year like 2017 or 2018).

Q21. Discuss the Content Packs in Power BI.

Ans. Content packs are pre-built solutions containing reports, dashboards, and datasets shared via the Power BI Workspace. There are service provider packs and user-created packs.

Q22. What are Custom visuals in Power BI?

Ans. Visuals created by developers using the SDK (using jQuery, D3, R-language) when standard visuals are insufficient.

Q23. What data sources can you connect to Power BI?

Ans.

  • Files: .pbix, Excel (.xlsx, .xlsm), CSV.
  • Content Packs: From providers like Google Analytics or Salesforce.
  • Connectors: Databases like Azure SQL and SQL Server Analysis Services.

Q24. How are a Power BI dashboard and a report different?

  1. Pages: Dashboard is 1 page; Report can be multiple pages.
  2. Data sources: Dashboard can have tiles from multiple datasets; Report has a single dataset.
  3. Filtering: Dashboard cannot perform filtering/slicing; Reports can.
  4. Alerts: Dashboards allow email alerts; Reports do not.
  5. Access: Dashboards don't allow viewing underlying tables; Reports do.

Q25. What is Power Pivot?

Ans. An in-memory component that enables storing compressed data, building data models, and creating relationships/formulas.

Q26. What is Power View?

Ans. A data visualisation technology for creating interactive charts and maps; available in Excel, SQL Server, and Power BI.

Q27. Define Power Query?

Ans. An ETL tool used to clean, shape, and transform data without code. You can import from various sources and append/join data.

Q28. What is the major difference between a Filter and a Slicer?

Ans. Users cannot interact with normal filters on a published dashboard, but they can interact with slicers to filter data themselves.

Q29. What is the Power BI Service?

Ans. A cloud-based analytics solution used to create dashboards, publish reports, and collaborate with stakeholders.

Q30. Tell us about the Excel add-ins for Power BI.

Ans. The Excel BI Toolkit includes several add-ins (like Power Query, Power Pivot, and Power View) to facilitate self-service BI within Excel.

Q31. Share some key points about DAX usage in Power BI?

Ans. Some key points about DAX:

  • DAX is a functional language, so its complete code is always a function.
  • An executable DAX expression generally contains conditional statements, nested functions, value references, etc.
  • DAX formulas have two primary data types: Numeric and Non-numeric.
  • The numeric data type includes integers, decimals, currency, etc.. The non-numeric consists of strings and binary objects.
  • DAX expressions are evaluated in an inward-to-outward fashion. It starts from the innermost function going to the outermost function last.
  • We can use values of mixed data types as inputs in a DAX formula.

Q32. Which table functions will you use to group data in Power BI?

Ans. We can use two main DAX functions to group data in Power BI - SUMMARIZE() and SUMMARIZECOLUMNS:

  • The SUMMARIZE function is used to group data by columns.
  • The SUMMARIZECOLUMNS function is generally used in Power BI to group data by columns, expressions, and tables.

Q33. Explain the concept of Power BI DAX.

Ans. The three fundamental concepts of Power BI DAX are Syntax, Context, and Functions.

  1. Syntax: It comprises various components that make up the formula. For e.g. - Total Sales = SUM(Sales[SalesAmount])
    • Total Sales is the Measure name.
    • The equals sign (=) indicates the start of the DAX formula.
    • SUM is used to add the values of a given field.
    • The parentheses () are used to enclose and define arguments in an expression.
    • Sales are the table referenced.
    • The referenced column [SalesAmount] is an argument with which the SUM function identifies the column on which it has to aggregate a SUM.
  2. Context: It is one of the essential concepts of DAX. There are two types of Contexts - Row Context and Filter Context.
    • The Row-Context is applied whenever a formula has a function that filters to identify a single row in a table.
    • Filter-Context is used when one or more filters are applied in a calculation.
  3. Functions: Functions are structured, predefined, and ordered formulae. They complete calculations using arguments passed on to them.

Q34. Explain some commonly used DAX functions.

Ans. Some of the most commonly used DAX functions are:

  • Date and Time Functions: These functions carry out calculations on the date and time values. Ex: DATE, CALENDAR, HOUR, MINUTE.
  • Time Intelligence Functions: These functions are used to evaluate values over a fixed period. Ex: DATESBETWEEN, ENDOFQUARTER, CLOSINGBALANCEMONTH.
  • Logical Functions: These functions are used to evaluate an argument or expression logically. Ex: AND, FALSE, IFERROR, IF.
  • Mathematical and Trigonometric Functions: These functions are used to perform all sorts of mathematical functions on the reference values. Ex: DIVIDE, FACT, ACOS.
  • Statistical Functions: These functions carry out statistical and aggregation functions on data values in a DAX expression. Ex: AVERAGE, COUNT, GENERATE.
  • Text Functions: These are similar to the string functions of Excel. Ex: FIND, LEFT, FIXED, FORMAT.
  • Table functions: In DAX formulas, these functions are used to apply operations and conditions on entire tables. Ex: FILTER, VALUES, DISTINCT.

Q35. What is a summarise function in DAX?

Ans. Summarise is a DAX function that gives an aggregated result from a table. This is how the summarize function is used: Summarize(<table>,<grouping column>,[<name>,<expression>])

  • table - a DAX expression that returns a table.
  • grouping column - the column name you want to use for grouping.
  • name - the name of the new aggregated column.
  • expression - generates the aggregated column.

Q36. What are DAX Calculation types?

Ans. DAX in Power BI has two types of calculations or formulas. These are:

  • Calculated Columns: These are used to merge new columns into existing ones with filters. These columns can be created from the Modelling tab in Power BI Desktop, where new columns can be created by entering their names and formulas.
  • Calculated Measures: They enable the user to create fields with aggregate values like average, ratio, percentage, etc. The measures are also created from the modelling tab of Power BI Desktop.

Q37. Explain Power BI Query Editor.

Ans. Power BI Query Editor is used to transform or edit data files before they are loaded. The Query Editor plays the role of an intermediate data container where you can transform data by selecting rows and columns, splitting rows and columns, pivoting and unpivoting columns, etc.. The modifications done by the Query Editor are not reflected in the actual datasheet.

Q38. Are Power View and Power Query the same?

Ans. No. Power Query can be used to download data to Excel as well as make nice transformations (Ex: Filter, merge multiple sources, calculate, etc.). Power View enables you to present the data in reports.

Q39. What is a parameter in Power BI?

Ans. A parameter serves as a way to easily store and manage a value that can be reused. Parameters give you the flexibility to dynamically change the output of your queries depending on their value, and can be used for changing the argument values for particular transforms and data source functions.

Q40. How to sort data in Power BI?

Ans. Sorting is available in multiple formats. In the data view, there is a common sorting option of alphabetical order. We have the option of sorting by column, where one can sort a column based on another column. Sort by ascending and descending options by the fields and measures present in the visual is also available.

Q41. How to combine two columns in Power BI?

Ans. To combine two columns in Power BI, you need to select a new calculated column using the DAX expression. For example, if you need to add the values of two columns & make the third column, you can do it by the following DAX Expression: Total=Sheet Name(Col1) +sheet Name(Col2).

Q42. What is Power BI Data Gateway? How can we use it?

Ans. Power BI Data Gateway is software used to access the data connected to a premise network from the cloud. On-premises data gateway acts as a bridge to provide quick and secure data transfer between on-premises data (data that isn't in the cloud) and several Microsoft cloud services, including Power BI, PowerApps, Power Automate, Azure Analysis Services, etc. To use Data Gateway, you first need to install it in your system; add the users to this who will be accessing the data from on-premise sources. Give authentication & request, and get connected to the On-Premise Data sources.

Q43. How is the filter function used in Power BI?

Ans. You can use FILTER to reduce the number of rows in the table


FAQs (Schema-Ready)

What is DAX in Power BI?

DAX is a formula expression language used in Power BI to create calculated columns and measures.

What is the difference between Dashboard and Report in Power BI?

Dashboard is single-page; Report can have multiple pages.

What are Power BI building blocks?

Visualisations, Datasets, Reports, Dashboards, and Tiles.

What is CALCULATE in DAX?

It calculates expressions with applied filters.

What is Power BI Service?

A cloud-based analytics solution used to publish reports and collaborate.

📌 For More Articles

For more in-depth tutorials, interview questions, SQL optimisation guides, and Power BI concepts, visit:

👉 https://softcodel.blogspot.com/

No comments:

Post a Comment