Top 80 Power BI Interview Question For Data Analyst PDF

Top 80 PowerBI Interview Question

1. Top 80 Power Bi

(With Answers )

=>TechTalks_with_Ajay
@AjayTripathi

2

2. + SECTION 1: Basics of Power BI
1. What ie Power BI?
Power Bis a business analytics tool by Merosof fr visualizing data and sharing insights
‘across an organization. I converts raw data int interactive dashboards and Bl repent,
2, What are the key components of Power BI?
+ Power BI Desktop
+ Power BI Service (Clous)
+ Power BI Mobte
+ Power BI Gateway
+ Power BIReport Server

+ Power BI Embedded

3. Difference between Power Bl Desktop and Power Bl Service?
+ Desktop: Used to create reports
Service: Used to shave and collaborate
4. What data sources can Power Bl connect to?
SQL Server, Excel, SharePoint, Azure, Oracle, Web APIs, and over 100+ connectors
5. What is DAX in Power BI?

Data Analysis Expressions (DAX) isa formula language used to create custom calulations in
Power Bl, Power Pet and SSAS,

3. ¡| SECTION 2: Power BI Data Modeling

6. What is a relationship in Power BI?
IS a connection between two tables based on a key column, allowing combined deta analysis.

7. Types of relationships in Power BI?

+ Oneto-One

+ Oneto-Many
+ Manyto-One

+ Meny-to-Many

8. What is cardinality in Power Bl relationships?
Itdefnes the uniqueness o dla values in elated columns (eg. one-to-mary)

3. What isthe difference between calculated column and measure?
+ Calculated column: Rowse computation stored inthe model

+ Measure: Compulaton evaluated at query Ime and optimized for performance,

10, Whats a calculated table?
‘Anew table created using DAX, offen for aggregations or fitering,

: SECTION 3: DAX (Data Analysis Expressions)

11, What i the uso of CALCULATE in DAX?
Itenanges the contest of calculation wi fier expressions

12 Difference between SUM and SUMK in DAX?

SU Adds up values trom a column.

Suis: Row-by:row evaluation wih an expression

13. Explain ALLO function in DAX.
Removes (tes from a table or column.

4. 44, What isthe use of FILTER( in DAX?
Retums a table thal represents a subset of another tae

415, What isthe difference between EARLIER and EARLIEST?
EARLIER is used in row context to reer to an outer row context EARLIEST is rarely used end
more complex.
16. What I context in DAX?
+ Row context: The curentrow,
+ Filler context: The ers applied
17. Whats the uso of RELATED( in DAX?
Pulsa value fom à related table
18, What ie the difference between DISTINCTO and VALUES?

+ DISTINCT Retums unique values om a column,

+ VALUES: Retums unique values +blankit exis

sh SECTION 4: Data Loading & Transformation

19. What ie Powor Query?
‘A data connection technology to impor transform, and clean data before loading into Power
a.

20. What is M language?
Power Query Formula Language used in Power Query Eder.

21. Difference between Power Query and DAX?

+ Power Query (My: PreJoad transformation

+ DAX Postioad caluatons and measures.

22, What fs the Quory Folding concopt?
Its when Power Query pushes transformations to the source database for better perfomance,

23, What are Append and Merge in Power Query?

5. Append: Adds rows

+ Merge: Combines columns tom wo tables

© SECTION 5: Visualizations & Reports

24, What is slicer in Power BI?
A visual iter that allows users o interactively fier oler visuals

25, What ie a bookmark in Power BI?
Used to capture and share specific views ofa report

26. What ie drithrough in Power BI?
‘Allows navigation toa detailed report by right-clicking on a data point

27. What is dril:down and drip?
Navigating hierarchical data — going ram summary to details ar vice versa.

28. What are tooltips?
Hover-over boxes that show additional data

28. What are KPI visuals in Power BI?
Visuals that show progress toward a goal (key performance indicators)

30. What isa custom visual?
A visual developed using SDK or downloaded trom AppSource

à SECTION 6: Security & Sharing

31. What is RowLevel Security (RLS)?
‘technique 1 reset data access for spectc users atthe row level.

32. How is RLS implemented in Power BI?
‘By creating roles ana using DAX ers

33. What isthe Power Bl Gateway?
À bnége between on-premises dala sources and Power Bl cloud serve.

34. Difference between personal and ei

rprise gateway?

6. + Personal: For individual use

+ Entero: For multiple users and scheduling

35. How do you share Power Bl roports?

«Pub to Power Bl Service
+ Sharo dashboards via workspace

+ Embed in apps or SharePoint

'% SECTION 7: Performance Optimization

36. What isthe star schema?
À cata modeling approach win fact and dimension tables,

37. Difference between star and snowflake schema?
Snoutake normalizes dimension table: star keeps them dencrmaizes

38. Tips to optimize Power Bl performance?

+ Usestarschema
Limit eats

+ Use variables in DAX

+ Avoid complex calevated columns

+ Use DirectQuery cautiously

The in-memory engine of Power lor data compression an fast query performance

40. What isthe use of variables in DAX?
Improves performance and ready

7. + SECTION 8: Advanced Topics

41. What is DirectQuery?
eonnects to ve data without importing it

42. Difference between Import and DirectQuery?
+ Import Faster stores cata
+ OiretQuery Real-time, slower, mite features

43. What is Composite Model?

‘Allows combining Import and OirectQuery in the same report

44. What is Incremental Refresh?
Refrshes only newichanged data rather than the entre detaset

Dynamic inputs or Bering or modiing queries.

46. What is deployment pipeline?
Move report trom development test production

47. What is Power Bl Paginatod Report?
Pive-perlec report created using Report Bulder for printrafexportng,

48. Can you explain dilthrough fito?
They pass context to ancther report page based on selected data,

I SECTION 9: Real-Time & Embedded

48. How do you create real-time dashboards?
By connect to seaming datasets om APIS or Azure.

50, What is Powor BI Embedded?
Embedding Power Bl visuals in custom applications using REST API

8. SECTION 1

51. How do you handle many-to-many
Using a bridge table and appropriate DAX

cenario-Based / Problem Solving

ionships?

52. How do you compare e to last year?

Using SANEPERIODLASTYEAR( ) or DATEADD

53, How to calculate running total in DAX?
Use CALCULATE(SUM( [Sales] ), FELTER(ALLSELECTED(

54, How to calculate percentage of total in Power BI?
ALCULATE(SUM( [Measure]}, ALLLTabL

55, À user wants a report but must not sae other data — how will you do that?
Use RLS with USERNAME() or LOOKUPVALUE() in DAX

X SECTION 11: Common Functions in DAX

56. What is DIVIDE()? Why is it proferred over /?
Handles aivde-by-zero emors gracefully

ST. How does SWITCH() work in DAX?
Itreplaces nested IF statements for multple conditions.

58, What is LOOKUPVALUE))?
‘Searches a value in a column and retuns the related value from another column.

59. What does USERNAME() function return?
The log ID of he user, useful for RLS.

60, What does ISFILTERED() return?
TRUE ita column or table is fered

9. \ SECTION 12: Debugging & Troubleshooting
Gt. How to debug DAX formulas?

+ Use varabies

+ Use DAX Studio

62. How to detect performance issues in Power BI?
Use Performance Analyzer, DAX Stuco, Query Diagnosis.

63. Common reasons for slow reporte?
+ Heavy visuals
+ Bag Dax
+ Too many visuals

+ Using Diectouery

+ SECTION 13: Version Control and Collaboration
64, Howto manage version control in Power 817
+ Use source contol (e. Gi) with PBIX Mes

+ Document changes and maintain backups

65. Howto collaborate on a Power Bl report?
+ Use shares workspaces
+ Assign roles

+ Uso ceployment pipelines

10. + É SECTION 1

Common Pitfalls and Best Practices
66. What are common mistakes in Power BI development?

+ Ignoring data model

+ Overoading visuas

+ Avoicing star schema

+ Not using measures property

67. How to reduce flo size of PRIX?
+ Remove unused columns
+ Reduce granular

Optimize DAX and model

68. When to use Import ve. DiroctQuery?
+ Import Pertormance-neawy fast

+ DieclQuery Realtime, lage datasets

_] SECTION 15: Automation & Integration

68, What ao dataflows in Power BI?
Reusable ETL pipelines in Powe Bl service

70. Can Power Bl connect to APIs?
Yes, using Web connector er Power Query

71. Can you automate report delivery?
Yes, using subsctipions or Power Automate,

12. Can Power Bl riggor workflows?
Yes, using Power Automate integration,

11. © SECTION 16: Miscellaneous Questions
73. What’ the difference between dashboard and report in Power BI?

Dashboard: Single page interactive view only inservice)

+ Report: Mutt page, buin Desktop

74, How to schedule refresh in Power BI?
Setup in Power Bi Service using 8 data gateway

75.Can you embed Power Bl into SharePoint?
Yes, using Power Bl web par,

76. What inthe role of Power B Admin?
Manage workspace. user acces, leering. and Sing

TZ. What ae datasets, datatows, and datemarts?
+ Dates Imports datan a rap
+ Datatows: ETL loge neous
+ Dalamar: Sel service database + model + SOL intrace

78, How to monitor Power Bl usage?
‘Using Poner Bl au logs or Admin portal usage metres.

techniques ke AQgtepatons, Orectavery. and Azure Synapse,

80, How does licensing work in Power BI?
+ Free: Only Power Bi Desktop
+ Pro: Share 8 cotaborate

+ Premium Dedicated capacty, entepise features

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