Top Power BI Interview Questions And Answers

This Power BI interview questions and answers guide created by industry experts to help you clear interview rounds in a one go.

The rise of business intelligence (BI) tools happened back in 2011, when Microsoft too realized the need of the hour - to build a BI tool of its own. They made it happen in 2015, with the release of Microsoft Power BI for the general audience. In less than a decade of its existence, Power BI has become the most sought-after name for all analytical needs.

More companies than ever are looking to hire skilled and certified Power BI professionals. Once you complete your Power BI training and certification, the only thing left to do will be to ace your interview. This is where our blog comes in the picture to help you.

Here is a list containing the top Power BI interview questions and answers. Whether you are a beginner, a developer, or an experienced professional, this blog has it all. Let's start with a few Power BI basic interview questions.

Job Opportunities in Power BI

Before you begin reading Power BI interview questions, let us take a look at the top career opportunities in Power BI. While many people think that after learning Power BI, they can only become a developer. However, that is far from true.

Power BI skills are high in demand across various organizations on a global level. Once you ace it, you will easily be able to tap into various job profiles. The ones listed below are only a few top chosen ones.

• Power BI Developer

• Power BI Consultant

• Power BI Architect

• Power BI Business Analyst

• BI Specialist

• Power BI Data Analyst

• BI Report Developer

Power BI Questions for Freshers

Here are a few often-asked Power BI questions and answers for beginners. Going through these will help you get your basic questions sorted out.

Question 1. What is Power BI? How does Power BI benefit businesses?

Ans. Power BI is a pool of BI tools that facilitate companies in visualizing and sharing insights from their valuable data. Power BI enables businesses to enhance their competitiveness and efficiency by aiding them in making informed and data-driven decisions.

Question 2. What are the major components of Power BI?

Ans. The major components of Power BI are:

• Power BI Desktop
• Power BI Service
• Power BI Embedded
• Power Pivot
• Power BI Report Server
• Power BI Mobile Apps
• Data Sources
• Power BI Gateway
• Power BI Report Server
• Power BI Query
• Power View
• Power Q&A
• Power Maps

Question 3. Give a list of Power BI data sources.

Ans. Various data sources supported by Power BI include:

• Cloud-based services (for instance, Salesforce, Azure SQL Database, Google Analytics)
• Web-based sources (for instance, OData feeds, REST APIs)
• Relational database (for instance, Oracle, SQL Server, MySQL)
• On-premises data sources (for instance, Hadoop, SharePoint)
• File-based sources (for instance, CSV, XML, Excel, JSON)

Question 4. What are the different types of filters in Power BI reports?

Ans. There are many different types of filters in Power BI reports namely,

• Visual-level filters
• Report-level filters
• Relative data filters
• Top N filters
• Cross-filtering & cross-highlighting
• Page-level filters
• Relative filters
• Drillthrough filters
• Slicer filters
• Advanced filters using DAX

Question 5. What is the use of a data gateway in Power BI?

Ans. Data gateway in Power BI is a service. It aids businesses in securely transferring data between Power BI Service and on-premises data sources. This service plays the role of a connector between these two. The data can be assessed from on-premises sources directly by Power BI, without exposing it to the internet.

Question 6. How many types of data gateways are in Power BI?

Ans. There are two data gateways in Power BI. These come in two modes, namely personal mode and standard mode.

• Personal Mode: The personal mode is basically for one-person use instead of a team. It is mostly opted for by a data analyst.
• On-Premises Mode: The on-premises mode is opted by organizations that  want its team to work together in a collaborative environment. Power BI developers and BI admins generally use it.

Question 7. Is there any prerequisite for installing Power BI?

Ans. There are only two prerequisites for installing Power BI. First, a web browser is essential and second, a work email address that either ends in .org or .edu.

Question 8. What are four types of cardinality in Power BI?

Ans. The four types of cardinality in Power BI are:

• One to one
• One to many
• Many to one
• Many to many

Power BI Interview Questions and Answers for Intermediate Level

Before we move onto Power BI interview questions for experienced professionals, let's take a look at some for the intermediate level.

Question 9. Name the different views in Power BI Desktop.

Ans. There are three distinct views in Power BI Desktop. Each of these serve a unique purpose.

• Report View: Report View is where users are able to add report pages and visualizations. It can also be published on the portal from here itself.
• Data View: Once data has been modeled, it gets reflected in the Data View. Here, the visuals you have created are laid out piece by piece, like in a grid.
• Relationship View: Also referred to as the Model View, it facilitates creators to take a look at the relationships shared between their data models. 

Question 10. What is Advanced Editor in Power BI?

Ans. Advanced Editor in Power BI facilitates us to view the code that has been created with Power Query Editor at every step of the editing process. Hence, at any point during the entire editing process, we can click on Advanced Editor to see the updated code. It runs on the Power Query Formula language, also called ‘M'.

Read Also- Power BI Tutorial

Question 11. What is a dashboard?

Ans. A dashboard in Power BI refers to a single page that often states a story using visualizations. Often also referred to as a canvas, it is a well-defined representation that only depicts the highlights. For in-depth reports, additional related reports can be viewed.

This BI tool facilitates users in tracking, reporting, and analyzing KPI and other metrics. It is a collection of graphs, maps, and charts to ensure stakeholders comprehend, collaborate, and share the information.

Question 12. Which refresh options are available in Power BI?

Ans. There are plenty of options available in Power BI to refresh data. However, the most often used ones are:

• Scheduled Refresh: We can set up a refresh schedule for the datasets with scheduled refresh. The timing and frequency of the refreshes can also be specified.
• Live Connection: A direct connection with cloud-based or on-premises data sources can be established with live connection. These include Azure Analysis services, Power BI datasets, or SSAS.
• Incremental Refresh: With this, only the changes since the last refresh will be refreshed, rather than completely refreshing the entire dataset.
• On-Demand Refresh: This entails manually triggering a dataset to refresh as and when needed.
• DirectQuery: Users who do not want to import data into Power BI, but rather directly run the queries against the data source should use DirectQuery.

Question 13. Give a comprehensive view of Power BI's working system.

Ans. Power BI runs on four key steps. These are:

• Data Import: The primary step is to import data from different sources and convert it all into a standardized format to proceed further.
• Data Cleaning: After gathering data, it is sent through a transformation process. The aim is to eliminate any irrelevant or unnecessary information for a clean dataset. 
• Data Visualization: The previously processed data is next visually represented via interactive dashboards and reports by using various robust visualization tools. 
• Save & Publish: Once the reports are created, the finalized ones are saved and published. This enables seamless collaboration and sharing. These reports can be easily accessed via web platforms and mobile apps.

Question 14. Why should general formatting be applied to data in Power BI?

Ans. General formatting should be applied to data in Power BI for the following reasons:

• Creates consistency
• Visual categorization
• Ensures brand consistency
• Well-formatted reports
• Facilitates drill-down capabilities
• Improves communication
• Saves time and efforts
• Better readability
• Promotes data-driven decision making
• Allows conditional formatting

Power BI Interview Questions For 5 Years Experienced Professionals

Are you an experienced professional who is looking for a job change? Well, this is the list of the top Power BI interview questions for 5 years experience. Let's get started!

Question 15. What is the M query language in Power BI?

Ans. The M query language in Power BI is used in the Query Editor. It aids in preparing the data prior to being loaded into the Power BI model. Power Query's key function is to merge data from different supported sources, which are then expressed by using Power Query M Formula Language.

Question 16. Explain query folding in Power Query.

Ans. Query folding in Power Query is a process wherein certain set steps are translated into SQL. These are then executed by the source database, and not by the client machine.

This process has importance because it ensures scalability and optimizes performance in data processing.

Question 17. Explain the fundamental concepts of DAX.

Ans. There are three fundamental concepts of DAX. These are:

• Syntax: Syntax includes functions and hence, if it is wrong, the final result would reflect an error.
• Context: There are two types of context namely filter context and row context. It is an integral aspect and very helpful for organizations. 
• Functions: These refer to arguments that are to be performed by a specific order.

Question 18. What is Power Pivot?

Ans. Power Pivot is an add-in for Microsoft Excel 2010, which facilitates users in importing millions of data rows to a single Excel Workbook from multiple sources. Users can perform various tasks, including creating bridges between heterogeneous data, creating calculated columns, and using formulas to measure.

It can also be used for building PivotTables and PivotCharts. Data is analyzed effectively to aid organizations make data-driven decisions.

Question 19. Why are CORR functions used?

Ans. CORR functions or correlation functions are used for finding the relationship shared by any two given attributes or values. There are numerous correlation functions, of which, Pearson correlation is the most widely used and popular.

Correlation can be positive or negative. Positive correlation implies that the values that are being compared with increase simultaneously. Alternatively, negative correlation implies that one value will decrease and one will increase.

Power BI Technical Interview Questions

Power BI technical interview questions are usually posed to those with some working experience of the tool. Hence, if you are not a complete fresher, then be prepared to be asked such questions.

Question 20. How to create custom visuals in Power BI?

Ans. The Custom Visual SDK can be used to create custom visuals in Power BI. It is based on D3.js and JavaScript. The steps to make it happen are:

• Set up the Power BI environment to accommodate custom visual development
• Explore the custom visual options available in Power BI
• Create basic visualizations 
• Improve these custom visuals by employing advanced functionality and features
• Test and debug them

You May Also Read- How to Become a Power BI Developer?

Question 21. What is a star schema? 

Ans. A star schema refers to a multi-dimensional data model that is employed by enterprises to organize their data in a database. The purpose is to make this data easily understandable and analysis-ready. It is simpler to maintain, understand, and design. It provides swift integration with data cubes and OLAP systems.

Question 22. What is cardinality in Power BI?

Ans. Cardinality, in terms of Power BI, refers to the number or relationship of distinct values shared among two tables in a data model. It gives a clear picture on what the rows of one table have to do with the rows of another table, on the basis of specified column(s).

Question 23. What is a common issue that arises upon using many-to-many cardinality in a relationship?

Ans. Many-to-many cardinality in a relationship can certainly lead to issues when different levels of granularity are present in the data. This can lead to duplications in the datasets that have returned, causing incorrect results.

Question 24. What is the concept behind row-level security in Power BI?

Ans. Row-level security, also called RLS, is a powerful Power BI feature that facilitates in restricting all data access for certain users as per their attributes or roles. DAX expressions are designed to implement RLS. These filter the data model as per the user's context so that the user is only able to see what they have been authorized to see.

Question 25. How is a donut chart different from a pie chart in Power BI?

Ans. A donut chart in Power BI has a hold in the middle, giving it a ring-like structure and appearance. A pie chart, on the contrary, is a complete circle wherein the data is displayed in segments.

Both charts are used to showcase proportions of different categories of a complete whole. However, a donut chart is able to display more info in the center.

Question 26. What is the concept of data profiling here?

Ans. Data profiling in Power BI refers to examination and analysis of data. The purpose is to understand the quality, distribution, and structure of data. It can be performed via Power Query, which offers different profiling features. These features include data type detection, error highlighting, and column statistics, among others.

It is important to identify inconsistencies, outliers, and data quality issues. If unidentified, these can lead to negative effects on the reliability and accuracy of reporting and analysis.

Power BI Developer Interview Questions

As a developer, you must already know how important it is to give your hundred percent in an interview, because of the high competition. Here is a list of a few top Power BI developer interview questions to revise before going for your interview.

Question 27. What are the different connectivity modes in Power BI?

Ans. There are three major connectivity modes that you should know about in Power BI:

A. Direct Query: With direct query, direct connection is made with the Power BI model. Since Power BI stores only the metadata of the data tables, the data does not get stored there. A few supported sources of data query include

• Azure HDInsight Spark (Beta)
• IBM Netezza (Beta)
• SAP Business Warehouse (Beta)
• Spark (Beta) (version 0.9+)
• Amazon Redshift
• SAP HANA
• SQL Server
• Azure SQL Database
• Impala (version 2.x)
• Snowflake

B. Live Connection: This mode is quite similar to direct query in the sense that no data is stored with it in Power BI either. However, the difference is that there is a direct connection between live connection and analysis services model. The supported data sources are

• SSAS (SQL Server Analysis Services) Multidimensional
• SSAS Tabular
• Power BI Service

C. Import Data: With this method, the data can be uploaded into Power BI, which consumes the Power BI desktop space. When uploaded on the website, the Power BI cloud machine space is consumed. It is the fastest method but the uploaded file size cannot exceed 1GB with the free version. With Power BI premium, it can go till 50GB.

Question 28. Where is the data stored in Power BI?

Ans. Power BI has two key sources for data storage -

• Azure SQL Database: All system artifacts and metadata gets stored here.
• Azure Blob Storage: All uploaded data gets stored here.

Question 29. What is DAX?

Ans. DAX, which is an abbreviation for Data Analysis Expression, is a library of formulas that is employed for data analysis and calculations. It consists of operators, constants, and functions for performing calculations and driving out results. With DAX, data sets can be used to their optimum potential and churn out insightful reports.

Question 30. What are filters in Power BI?

Ans. In Power BI, filters are used for sorting data on the basis of the condition applied. It enables us in selecting a specific field(s) and further extracting information in a report/ visualization/ page level. There are three types of filters namely,

• Visualization-level filters
• Report-level filters
• Page-level filters

Question 31. How can confidential data be secured in Power BI in an organization?

Ans. Row-level security can be used in Power BI to hide confidential data. This helps in restricting the data on the basis of the roles curated as per the profile or group of people.

Question 32. What is Power View?

Ans. Power View in Power BI refers to a data visualization technology for creating interactive maps, charts, graphs, and much more. It aids to analyze data patterns and extract meaningful insights from the same.

Question 33. What is Time-Series analysis?

Ans. Time series analysis aids developers in analyzing the data patterns to find trends, seasonality, and cyclicity over a period of time. It is helpful for businesses as it facilitates them in making informed business decisions.

Power BI Developer Salary In India, USA & UK

Let us take a look at the average annual Power BI salary enjoyed by a Power BI developer globally as per their experience level.

USA

Entry-level positions - $95k

Mid-level experienced professionals - $112k

Most experienced professionals - $140k

India

Entry-level positions - ₹3 LPA - ₹6 LPA

Mid-level experienced professionals - ₹3.6 LPA - ₹9.0 LPA

Most experienced professionals -  ₹10 LPA - ₹20 LPA

UK

Entry-level positions - 40,000 GBP

Mid-level experienced professionals - 46,138GBP

Most experienced professionals - 65,000 GBP

Final Words

There are plenty of Power BI interview questions and answers to explore, depending upon your level of experience and expertise. This blog is an amalgamation of some of the key interview questions for Power BI to help you get into any organization that you have aimed at.

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