This post is a part of the PL-300: Microsoft Power BI Data Analyst Exam Prep Hub; and this topic falls under these sections:
Model the data (25–30%)
   --> Design and implement a data model
      --> Configure table and column properties

Below are 10 practice questions (with answers and explanations) for this topic of the exam.
There are also 2 practice tests for the PL-300 exam with 60 questions each (with answers) available on the hub.

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Practice Questions

Question 1

You notice that a column containing Customer IDs is being summed in report visuals by default.
What is the best way to prevent this behavior?

A. Change the data type to Text
B. Hide the column
C. Set Default Summarization to Do not summarize
D. Create a measure instead

✅ Correct Answer: C

Explanation:
Default Summarization controls how numeric columns aggregate in visuals. ID columns should not be summed, so setting them to Do not summarize prevents incorrect totals while still allowing the column to be used where appropriate.

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Question 2

A report displays month names alphabetically instead of chronologically.
Which column property should you configure to correct this?

A. Data Category
B. Default Summarization
C. Sort By Column
D. Column Visibility

✅ Correct Answer: C

Explanation:
The Sort By Column property allows a text column (Month Name) to be sorted using a numeric column (Month Number), ensuring correct chronological order.

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Question 3

You want to prevent report authors from accidentally using surrogate key columns in visuals.
What should you do?

A. Change the data type
B. Hide the columns
C. Disable summarization
D. Remove the columns from the model

✅ Correct Answer: B

Explanation:
Hiding columns removes them from the Fields pane while keeping them available for relationships and internal model use.

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Question 4

A column containing website URLs should appear as clickable links in reports.
Which property must be configured?

A. Data Type
B. Format
C. Data Category
D. Default Summarization

✅ Correct Answer: C

Explanation:
Setting the Data Category to Web URL enables Power BI to render values as clickable links in visuals.

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Question 5

You are preparing a shared dataset for enterprise use. Users frequently ask what certain fields represent.
Which feature best addresses this issue?

A. Column formatting
B. Column descriptions
C. Data categories
D. Column visibility

✅ Correct Answer: B

Explanation:
Descriptions provide tooltips in Power BI Desktop and Service, improving documentation and usability without affecting calculations.

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Question 6

Which column should typically have Default Summarization set to “Do not summarize”?

A. Sales Amount
B. Quantity Sold
C. Discount Percentage
D. Customer ID

✅ Correct Answer: D

Explanation:
Identifiers should never be aggregated. Summing or averaging IDs produces meaningless results.

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Question 7

You want a column representing cities to work correctly in map visuals.
Which property should you configure?

A. Sort By Column
B. Data Category
C. Format
D. Column Visibility

✅ Correct Answer: B

Explanation:
Setting the Data Category to City helps Power BI geocode the data correctly for map visuals.

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Question 8

Does hiding a table or column improve model performance?

A. Yes, it reduces memory usage
B. Yes, it reduces refresh time
C. No, it only affects usability
D. Only for calculated columns

✅ Correct Answer: C

Explanation:
Hiding objects only impacts the user interface. It does not affect performance, refresh time, or memory usage.

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Question 9

Which table type most commonly contains hidden key columns and visible descriptive attributes?

A. Fact table
B. Dimension table
C. Bridge table
D. Calculated table

✅ Correct Answer: B

Explanation:
Dimension tables expose descriptive fields (Name, Category) while hiding primary keys used only for relationships.

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Question 10

A numeric column representing profit margin (percentage) is being summed in visuals, causing incorrect results.
What is the best configuration?

A. Change the data type to Text
B. Set Default Summarization to Average or Do not summarize
C. Hide the column
D. Convert it to a measure

✅ Correct Answer: B

Explanation:
Percentages are non-additive. Changing the default summarization prevents misleading totals while keeping the column usable.

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Key PL-300 Exam Takeaways

• Default Summarization is frequently tested
• Sort By Column is essential for time-based attributes
• Data Category impacts maps and URLs
• Hiding fields improves usability, not performance
• Descriptions matter for shared and certified datasets

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