🧠 Power BI Certification (PL-300) Questions & Answer
1. Prepare the Data (15–20%)
| No. |
Question |
Answer |
Explanation |
| 1 |
Which Power Query feature allows you to detect null values or outliers? |
Column Profiling / Data Profiling |
The Data Profiling feature in Power Query (Column quality, distribution, profile) identifies missing or abnormal values. |
| 2 |
Difference between “Import” and “DirectQuery” mode? |
Import stores data; DirectQuery reads live data |
Import caches data inside the model; DirectQuery queries the source every time—good for real-time, but slower. |
| 3 |
How to handle changing column names in a data source? |
Use column headers by position or rename columns manually |
Prevent refresh errors by renaming columns in Power Query to fixed names or using “Transform → Rename Columns.” |
| 4 |
What does the “Enable Load” option in Power Query do? |
Controls if query appears in the model |
Disable load for intermediate queries to improve performance and reduce model size. |
| 5 |
When should you use parameters in Power Query? |
For dynamic inputs such as file paths, dates, or filters |
Parameters allow reusability and automation for different environments (Dev/Test/Prod). |
2. Model the Data (30–35%)
| No. |
Question |
Answer |
Explanation |
| 6 |
What type of relationship is created when both fields have unique values? |
One-to-one relationship |
Both tables have unique keys—rare but sometimes needed for lookups. |
| 7 |
Difference between calculated column and measure? |
Column is row-level; measure is aggregated at query time |
Columns are stored in model, increasing size; measures are computed dynamically for better performance. |
| 8 |
Function of RELATED() DAX function? |
Fetches a value from a related table |
It follows a relationship to bring related column values into current context. |
| 9 |
How do you create a hierarchy in Power BI? |
Drag fields (e.g., Year → Quarter → Month → Day) into hierarchy |
Used for drill-down analysis in visuals. |
| 10 |
Star vs. snowflake schema? |
Star: single-level dimension; Snowflake: normalized dimensions |
Star schema improves performance and is recommended for Power BI. |
| 11 |
Purpose of Row-Level Security (RLS)? |
Restricts data access per user |
Filters the model data so each user sees only their allowed subset. |
| 12 |
DAX function to calculate year-to-date values? |
TOTALYTD() |
Calculates cumulative total from beginning of year to current date. |
| 13 |
How does Power BI handle circular relationships? |
It prevents them and prompts an error |
You must remove one link or redesign model to avoid ambiguity. |
| 14 |
Effect of “Cross Filter Direction = Both”? |
Filters flow in both directions |
Useful in many-to-many relationships but can cause ambiguity if overused. |
| 15 |
Difference between SUMX() and SUM()? |
SUMX iterates row-by-row; SUM aggregates one column |
SUMX = table expression + expression evaluation; SUM = simple column sum. |
3. Visualize and Analyze the Data (25–30%)
| No. |
Question |
Answer |
Explanation |
| 16 |
Purpose of slicer? |
Interactive filtering for visuals |
Allows end users to dynamically filter report content. |
| 17 |
How to sync slicers across pages? |
Use “Sync Slicers” pane |
Lets you control slicer visibility and synchronization across pages. |
| 18 |
Which visual best shows trend over time? |
Line chart |
Ideal for time-series data to show progression or trends. |
| 19 |
What are drillthrough pages used for? |
Detailed analysis of a selected data point |
Allows focusing on one item from a summary visual. |
| 20 |
Difference between filter, slicer, and visual-level filter? |
Scope: report, page, or visual |
Filter pane = global or page-specific; slicer = user-interactive; visual-level = affects one chart. |
| 21 |
How to add conditional formatting? |
Use “Format → Conditional Formatting” on fields |
Change color, data bars, icons based on measure values. |
| 22 |
Use of “Analyze” feature (“Explain the Increase”)? |
AI-driven analysis of variance in visuals |
Helps identify causes for change in a measure automatically. |
| 23 |
Role of bookmarks and buttons? |
Create interactive storytelling/navigation |
Bookmarks save visual states; buttons trigger them for user experience. |
| 24 |
How to customize tooltip information? |
Use “Report Page Tooltips” |
Create a mini report page and assign as tooltip to visuals. |
| 25 |
How to show KPIs in Power BI? |
Use KPI visual or card visuals with targets |
Compare actual vs target performance metrics. |
4. Deploy and Maintain Assets (20–25%)
| No. |
Question |
Answer |
Explanation |
| 26 |
Difference between a workspace and an app? |
Workspace = build area; App = published package |
Apps share finalized content securely with users. |
| 27 |
How to schedule dataset refreshes? |
In Power BI Service → Dataset Settings → Schedule Refresh |
Automates data updates at defined intervals. |
| 28 |
What are gateways used for? |
To connect on-premises data to Power BI cloud |
Required for refresh and DirectQuery to local sources. |
| 29 |
How to share reports securely? |
Publish to workspace → share via app or permissions |
Manage access with Azure AD or distribution groups. |
| 30 |
How to monitor dataset refresh failures? |
Use refresh history or Power BI admin portal alerts |
Provides error logs for troubleshooting. |
| 31 |
Permissions required to publish to a workspace? |
Contributor or higher |
Roles: Viewer, Contributor, Member, Admin. |
| 32 |
Role of sensitivity labels? |
Classify and protect confidential data |
Integrates with Microsoft Purview for data governance. |
| 33 |
Deploy dataset from dev to prod workspace? |
Use Deployment Pipelines |
Promotes content across development, test, production stages. |
| 34 |
Purpose of Power BI Dataflows? |
Reusable ETL processes in cloud |
Built using Power Query online for multiple reports. |
| 35 |
How to monitor performance? |
Use Performance Analyzer |
Captures DAX query times and visual rendering time. |
5. Advanced and Scenario-Based
| No. |
Question |
Answer |
Explanation |
| 36 |
Need real-time updates — which connection mode? |
Streaming dataset or DirectQuery |
Streaming = push data in real-time; DirectQuery = live connection. |
| 37 |
Report is slow to load — first step? |
Check model size and visuals using Performance Analyzer |
Identify whether bottleneck is DAX, visuals, or query. |
| 38 |
DAX for rolling 12-month average? |
AVERAGEX(DATESINPERIOD(...)) |
Uses DATESINPERIOD with CALCULATE/AVERAGEX for moving averages. |
| 39 |
Difference between Import, DirectQuery, Live Connection? |
Import = cached; DirectQuery = source queried; Live = external model |
Live connection is for Analysis Services or Power BI datasets. |
| 40 |
Implement dynamic RLS? |
Use USERPRINCIPALNAME() or USERNAME() in DAX |
Filters data dynamically per logged-in user. |
| 41 |
Benefit of composite models? |
Combine Import + DirectQuery |
Offers flexibility in performance and data freshness. |
| 42 |
What are deployment pipelines? |
Dev–Test–Prod workflow automation |
Ensures version control and governed release management. |
| 43 |
Reduce dataset size? |
Remove unused columns, use proper data types, aggregate tables |
Optimizes memory and refresh time. |
| 44 |
Visual to compare performance across categories? |
Bar or column chart |
Ideal for comparing values among discrete categories. |
| 45 |
Refresh data every 15 minutes — how? |
Use Power BI Premium or push dataset |
Standard Power BI Pro allows 8 refreshes/day; Premium allows 48. |
6. Case Study-Style Questions
| No. |
Scenario |
Recommended Solution |
| 46 |
Track sales by region and category with drilldown |
Use star schema, build hierarchies, and use matrix or treemap visuals with drilldown. |
| 47 |
Dataset grows daily, causing slow refresh |
Use incremental refresh with date range filters and partitioned refresh policies. |
| 48 |
Need to share with external users |
Use Power BI App + Azure B2B guest access or Publish to web (non-secure) depending on sensitivity. |
| 49 |
Managers should see only their team data |
Implement dynamic RLS with USERPRINCIPALNAME() and mapping table of managers–teams. |
| 50 |
Publish a dashboard with auto-updates |
Use DirectQuery or streaming dataset + scheduled refresh in service + pin visuals to dashboard. |
📘 Summary of Key Exam Facts
| Item |
Details |
| Exam Code |
PL-300: Microsoft Power BI Data Analyst |
| Type |
Multiple choice + scenario questions |
| Passing Score |
700 / 1000 |
| Duration |
100–120 mins |
| Languages |
English, Japanese, etc. |
| Official Learning Path |
Microsoft Learn – PL-300 |
🏆 How Palium Skills Helps You Succeed
Palium Skills provides hands-on Power BI training aligned with PL-300 certification objectives:
✅ Expert-led live sessions
✅ Case studies using real corporate datasets
✅ DAX practice sets & mock exams
✅ Guidance for career paths in Data Analytics
📍Contact: +91 8420594969 / 7044871915
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