Course quiz: Extract, transform and load Data in Power BI :Extract, Transform and Load Data in Power BI (Microsoft Power BI Data Analyst Professional Certificate) Answers 2025

Question 1

Which of the following statements about data sources in Power BI is true?

❌ Power BI only supports data sources stored in Excel.
✅ Power BI supports both cloud-based and on-premises data sources.
❌ Power BI can only connect to data sources with a specific file format.

Explanation:
Power BI supports a wide range of cloud and on-premises data sources such as SQL Server, Azure, Excel, APIs, etc.

Question 2

True or False: Any data source marked as Beta or Preview has limited support and should not be used in production environments.

✅ True
❌ False

Explanation:
Beta/Preview connectors may change and lack full support, so they are not recommended for production.

Question 3

There are two ways to endorse datasets. ________ makes a dataset available to a broader audience, while ________ is more selective.

❌ Certification – promotion
✅ Promotion – certification
❌ Accessibility – promotion

Explanation:
Promotion increases visibility, while Certification requires approval and signals trusted data.

Question 4

In ________, data is stored in memory but can also be retrieved from the original data source.

❌ Import mode
❌ Direct Query mode
✅ Dual Mode

Explanation:
Dual Mode can act as Import or DirectQuery depending on the query context.

Question 5

Which data structure best suits quantitative, searchable, and sortable inventory data?

❌ Unstructured data
✅ Structured data
❌ Semi-structured data

Explanation:
Structured data fits relational tables and is ideal for analysis.

Question 6

Power BI uses scheduled ________ to automate tasks.

❌ Actions
❌ Triggers
✅ Tasks

Explanation:
Scheduled tasks automate refreshes and processing.

Question 7

True or False: Data types are defined at the row level.

❌ True
✅ False

Explanation:
Data types are defined at the column level.

Question 8

Which menu item deletes a specific step in Power Query?

❌ Edit Settings
❌ Delete Until End
✅ Delete

Explanation:
Delete removes only the selected transformation step.

Question 9

Which data error may inflate your dataset?

❌ Missing or null values
✅ Duplicate values
❌ Inconsistent data types

Explanation:
Duplicates increase row counts and inflate results.

Question 10

Which operation converts wide-format data into long-format data?

❌ Transform
✅ Unpivot
❌ Pivot

Explanation:
Unpivot stacks columns into rows.

Question 11

What should you do to append SalesCompany and SalesOther tables?

✅ Remove StoreName and rename SalesKey → SalesID and SalesPersonKey → SalesPersonID
❌ Remove StoreName only
❌ Rename columns only

Explanation:
Append requires same column names and structure.

Question 12

How do you show product name, price, and category name?

❌ Select fields from Product only
✅ Merge Product and ProductCategory on ProductCategoryID
❌ Append the tables

Explanation:
Use Merge Queries to bring category names.

Question 13

Some products have NULL ProductCategoryID but must still be shown. What join do you use?

❌ Inner Join
✅ Left Outer Join
❌ Full Outer Join

Explanation:
Left join keeps all products, even without a category.

Question 14

Which join lists only matching rows?

✅ Inner Join
❌ Full Outer Join
❌ Left Outer Join

Explanation:
Inner Join returns only matches.

Question 15

Which join retrieves all records from both tables?

❌ Left Outer Join
✅ Full Outer Join
❌ Inner Join

Explanation:
Full Outer Join includes all rows from both tables.

Question 16

True or False: Join keys must be unique.

❌ True
✅ False

Explanation:
Keys don’t have to be unique, though uniqueness improves accuracy.

Question 17

Join keys provide a solution for ________ and ________.

❌ performance, scalability
✅ efficiency, scalability
❌ classification, categorization

Explanation:
Join keys reduce errors and scale well.

Question 18

As the data ________ process may involve large volumes, you monitor it carefully.

❌ Extraction
❌ Transformation
✅ Loading

Explanation:
Loading often handles large data volumes.

Question 19

You transform and consolidate data only for ETL use, not for reporting. What should you use?

❌ Reference query
✅ Staging area
❌ Query parameter

Explanation:
A staging area stores intermediate ETL data.

Question 20

Which option shows valid, error, and empty rows?

❌ Column distribution
❌ Column quality
✅ Column profile

Explanation:
Column profile gives a full validation view.

Question 21

What does Column distribution provide?

❌ Error and empty percentages
✅ Value distribution of a column
❌ Distinct and unique counts only

Explanation:
Column distribution shows how values are spread.

Question 22

Which definition best describes an anomaly?

❌ Measure of variability
❌ Statistical dispersion
✅ Data points that significantly deviate from others

Explanation:
Anomalies are outliers.

Question 23

Which technique applies changes across queries automatically?

❌ Query duplicating
❌ Dataflows
✅ Query referencing

Explanation:
Query references propagate changes.

Question 24

True or False: Reference queries can slow refreshes.

✅ True
❌ False

Explanation:
Referenced queries must refresh dependencies.

Question 25

True or False: Dataflows can be used in Power BI Desktop and Service.

❌ True
✅ False

Explanation:
Dataflows are created and managed in Power BI Service.

Question 26

Which technique focuses users on a specific category?

❌ Dynamic Data Retrieval
❌ Data Transformation
✅ Filters

Explanation:
Filters limit visible data.

Question 27

Primary benefit of dynamic data retrieval?

❌ Historical snapshots
✅ Real-time or near real-time analysis
❌ Large static storage

Explanation:
It fetches latest data from the source.

Question 28

________ determine data isolation and secure boundaries.

❌ Global options
✅ Privacy levels
❌ Data load options

Explanation:
Privacy levels control data interaction.

Question 29

By ________ expensive operations, you optimize performance.

✅ deferring
❌ prioritizing
❌ cancelling

Explanation:
Deferring expensive steps improves performance.

Question 30

Some ________ perform better with large datasets.

❌ Authentication mechanisms
✅ Connectors
❌ Data sources

Explanation:
Different connectors are optimized differently.

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