Question 1

In Power BI, how can you optimize a data model with a large number of rows for performance?

Accepted Answer

Use DirectQuery mode

Answer

Use a flat file structure

Answer

Increase the size of the data model

Answer

Disable data refresh

Question 2

What is the primary benefit of using calculated columns in a Power BI data model?

Accepted Answer

To perform row-level calculations in the data model

Answer

To directly update the source database

Answer

To improve data import speed

Answer

To replace measures in the data model

Question 3

Which of the following relationships should be avoided to optimize the performance of a Power BI data model?

Accepted Answer

Many-to-Many relationships

Answer

One-to-Many relationships

Answer

One-to-One relationships

Answer

Hierarchical relationships

Question 4

When dealing with time intelligence in Power BI, which feature should you use to handle complex time-based calculations?

Accepted Answer

DAX time intelligence functions

Answer

Custom visuals

Answer

SQL-based calculations

Answer

Power Query transformations

Question 5

What is the purpose of using the 'ALL' function in a DAX expression?

Accepted Answer

To remove filters from the data context

Answer

To create a new calculated column

Answer

To apply filters to the data context

Answer

To format the data

Question 6

How can you ensure that a Power BI report is responsive when dealing with large datasets?

Accepted Answer

Implement Aggregations

Answer

Disable report interactions

Answer

Increase the report page size

Answer

Use multiple data sources

Question 7

Which method can be used to improve query performance in Power BI by reducing the amount of data loaded?

Accepted Answer

Query Folding

Answer

Data Gateway

Answer

Data Flows

Answer

Incremental Load

Question 8

What is the primary use of the 'RELATED' function in DAX?

Accepted Answer

To fetch values from a related table

Answer

To join two tables

Answer

To filter data

Answer

To calculate a new measure

Question 9

How can you reduce the size of a Power BI data model?

Accepted Answer

Remove unused columns and tables

Answer

Add more calculated columns

Answer

Use more complex DAX functions

Answer

Increase the number of visuals

Question 10

Which of the following is a best practice when creating hierarchies in Power BI?

Accepted Answer

Include all levels of granularity needed for analysis

Answer

Only use hierarchies for time-based data

Answer

Avoid using hierarchies to keep the model simple

Answer

Create as many hierarchies as possible

Question 11

What is the effect of enabling 'Auto Date/Time' for new files in Power BI?

Accepted Answer

It creates hidden date tables for each date field

Answer

It disables manual date/time calculations

Answer

It automatically updates the data source

Answer

It formats the date fields in the report

Question 12

Which DAX function is used to calculate a running total in Power BI?

Accepted Answer

TOTALYTD

Answer

SUMMARIZE

Answer

SUMX

Answer

CALCULATE

Question 13

How do you create a measure in Power BI that dynamically changes based on user selections?

Accepted Answer

Use DAX functions like SWITCH and SELECTEDVALUE

Answer

Adjust the data source query

Answer

Use Power Query to create dynamic tables

Answer

Create a calculated column

Question 14

What is the primary advantage of using Power BI Dataflows?

Accepted Answer

To enable data reuse and consistency across multiple reports

Answer

To improve visualization performance

Answer

To create advanced custom visuals

Answer

To directly edit the data model

Question 15

What should be done to ensure that the Power BI model relationships are correctly defined?

Accepted Answer

Regularly review and validate relationships

Answer

Avoid creating relationships

Answer

Rely on Power BI service settings

Answer

Use only automated relationship detection

Question 16

Which feature in Power BI helps in handling very large datasets by aggregating data at various levels?

Accepted Answer

Composite Models

Answer

Power BI Embedded

Answer

Data Gateways

Answer

Power BI Templates

Question 17

When should you use a calculated table in Power BI?

Accepted Answer

When you need a new table based on existing model data

Answer

To create new data connections

Answer

To replace direct queries

Answer

To improve the data load performance

Question 18

What is a potential issue of using too many slicers in a Power BI report?

Accepted Answer

It can negatively impact report performance

Answer

It enhances the visual appeal

Answer

It improves the speed of data refresh

Answer

It simplifies the data model

Question 19

Which Power BI feature can help in creating a unified view of data from different sources?

Accepted Answer

Data Mashup

Answer

Bookmarks

Answer

Quick Insights

Answer

Q&A

Question 20

What is the primary use of the 'CALCULATE' function in DAX?

Accepted Answer

To modify the filter context of an expression

Answer

To aggregate data

Answer

To format date fields

Answer

To join two tables

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