Power BI Interview Questions Level 2

Top 100 Power BI Interview Questions

Level 2

Question 51: Which report type is best for printing and exporting?

The Paginated Report is best due to its fixed, page-oriented layout.

Question 52: What is the role of Tooltips in Power BI?

Tooltips display specific, supplementary information about a data point upon hover.

Question 53: How does the Export feature work in Power BI Desktop?

The Export feature allows you to export the report’s underlying data to formats like CSV or Excel.

Question 54: What is the difference between Analytical and Interactive reports?

Interactive Reports (Analytical) allow dynamic data exploration (filtering, cross-highlighting).

Question 55: What does the “Visual Interactions” setting control?

It controls how different visuals on a page filter or highlight each other when a selection is made.

Question 56: How can you highlight a specific data point in a report?

By selecting the data point on one visual, causing related data points on other visuals to be cross-highlighted.

Question 57: What is the use of the PBIT file format?

PBIT files are used to share a report’s structure and model without including the data.

Question 58: Which visual is best for showing proportions?

A Pie Chart or Donut Chart is generally best.

Question 59: What does the Play Axis feature enable in scatter charts?

It enables the animation of data points over a time or numerical variable to visualize trends.

Question 60: What is the purpose of the Mashup engine in Power Query?

The Mashup engine is the component responsible for extracting and combining data from various sources.

Question 61: How do you combine multiple tables in Power Query?

Using Append Queries (to stack rows vertically) or Merge Queries (to join columns horizontally).

Question 62: What transformation is used to split a column by delimiter?

The Split Column by Delimiter transformation.

Question 63: How do you create a custom column using expressions?

By selecting Custom Column and writing an M language expression to define the values.

Question 64: What does the “Merge Queries” option do?

It joins two tables based on matching values in one or more key columns, similar to a SQL join.

Question 65: What is the use of “Union All” in Power Query?

The equivalent is the Append Queries transformation, which stacks rows from one table onto another

Question 66: How do you apply filters in Power Query Editor?

By using the dropdown arrow on the column headers, similar to filtering in Excel.

Question 67: What is the difference between “Append” and “Merge”?

Append (Union All) combines tables vertically, and Merge (Join) combines tables horizontally.

Question 68: How do you transform date formats in Power Query?

By selecting the column and using the Date functions in the Transform tab (e.g., parsing, extracting parts, or setting data type).

Question 69: What is the role of “Step-by-Step” transformations?

The “Step-by-Step” transformations are recorded in the Applied Steps pane, allowing users to trace and manage the ETL history.

Question 70: What does the SUM function do in DAX?

The SUM function aggregates the total of all numbers in a column.

Question 71: How is the IIF function used in conditional logic?

The IIF (Immediate IF) function evaluates a Boolean expression and returns one value if true and another if false (a shorthand for the IF function).

Question 72: What is a calculated column in Power BI?

A calculated column is a new column added to a table in the data model, whose values are calculated using a DAX formula and stored in the model.

Question 73: What is the difference between a measure and a column?

A measure is calculated dynamically at query time; a calculated column is computed during data refresh and stores a static value per row.

Question 74: How do you create a running total using DAX?

By using the FILTER function within CALCULATE to accumulate values over a sorted range (e.g., all dates less than or equal to the current date).

Question 75: What does the FILTER function do in DAX?

The FILTER function returns a table that has been filtered down based on a specified Boolean condition.

Question 76: What is the purpose of DAX variables?

They simplify complex calculations, improve readability, and prevent redundant computations.

Question 77: How do you use SELECTEDVALUE in a report?

SELECTEDVALUE returns the single value currently selected in a slicer or filter context, often used for dynamic titles.

Question 78: What is the role of the VALUES function in DAX?

VALUES returns a single-column table containing the distinct values from the specified column, often used to check the current filter context.

Question 79: How does DAX handle blank values?

DAX handles blank values using functions like ISBLANK and the explicit BLANK() value.

Question 80: What is a Power BI workspace used for?

It is used for organizing and managing content, defining security roles, and facilitating collaboration among team members before publishing to a wider audience.

Question 81: How do you publish a PBIX file to Power BI Service?

By using the Publish button on the Home tab in Power BI Desktop and selecting the target workspace.

Question 82: What is the function of a data gateway?

A Data Gateway acts as a bridge, securely transferring data between the Power BI Service (cloud) and on-premises data sources.

Question 83: How do you schedule a refresh for a dataset?

In the Power BI Service, navigate to the dataset’s settings, configure the connection credentials, and set the refresh frequency and time slots.

Question 84: What is the difference between Import and Direct Query modes?

In Import mode, data is copied and stored in the Power BI model. In Direct Query mode, Power BI queries the source database directly.

Question 85: What does the Lineage View show in Power BI Service?

The Lineage View shows the end-to-end data flow, illustrating the connection from the original data source to the semantic model, and finally to the reports.

Question 86: How do you share a dashboard with external users?

Through Azure AD B2B (Business-to-Business) by inviting the external user’s email address to the organization’s tenant.

Question 87: What is the purpose of semantic models in Power BI Cloud?

They ensure a single source of truth for reporting and provide consistency across all consuming reports.

Question 88: How do you optimize a report for performance?

By using Direct Query sparingly, optimizing data model relationships, reducing the number of visuals, and writing efficient DAX/M code.

Question 89: What is the role of the Report Builder tool?

It is the tool used to author Paginated Reports (.RDL files).

Question 90: How does AI support data classification in Power BI?

AI can automatically classify data types and identify sensitive information within the dataset, helping with governance and security.

Question 91: How does CoPilot assist with report generation?

CoPilot automatically creates a draft report page with appropriate visuals, layouts, and suggested insights based on a natural language prompt.

Question 92: What is the role of Natural Language Query (NLQ) in Power BI?

NLQ (via the Q&A visual) allows users to type questions and receive a generated visual answer, making data accessible to non-technical users.

Question 93: How do you use Key Influencers visual?

The Key Influencers visual uses AI to analyze data and determine which factors most influence a selected metric (e.g., why sales increased/decreased).

Question 94: What is the purpose of the Decomposition Tree?

The Decomposition Tree uses AI to visualize and explore data across multiple dimensions, allowing users to drill down or branch out dynamically to find root causes.

Question 95: How does AI help in anomaly detection?

AI algorithms continuously monitor time-series data to automatically flag and explain unusual data points that deviate significantly from expected patterns.

Question 96: What are the benefits of using AI with Big Data?

Benefits include automated data classification, efficient pattern recognition, and the identification of complex anomalies and trends across vast and varied datasets.

Question 97: How do you implement AI visuals in Power BI Desktop?

By using the dedicated AI visuals in the Visualization pane, such as the Key Influencers visual or the Decomposition Tree.

Question 98: What is the use of Q&A in Power BI Cloud?

The Q&A feature allows users to ask natural language questions about their data, and Power BI automatically generates the appropriate visual answer.

Question 99: How does CoPilot support real-time analytics?

CoPilot supports real-time analytics by quickly summarizing and interpreting fresh data as it streams in, and by helping users rapidly generate the necessary visuals to monitor live data.