PL-300 Practice Test 4 — 10 Questions

Question 1

You are creating a Power BI report and need to add a visual that allows users to dynamically change the measure displayed in a chart. Which feature should you use?

Accepted Answer

Field parameters. Field parameters provide a way to let report users choose which measures or dimensions appear in a visual. By adding a field parameter to a slicer, users can select from a list of measures, and the visual updates accordingly. This is the most efficient method to achieve dynamic measure switching without creating multiple visuals or bookmarks.

Answer

Bookmarks

Answer

What-if parameters

Answer

Calculation groups

Question 2

Which TWO actions can improve performance of a Power BI DirectQuery model?

Accepted Answer

Ensure proper indexing in the source database. Proper indexing in the source database reduces the query execution time for DirectQuery models. DirectQuery sends queries to the source database in real-time, so efficient indexes on columns used in filters, joins, and aggregations minimize table scans and improve retrieval speed.

Answer

Switch the model to Import mode

Answer

Enable bidirectional cross-filtering on all relationships

Answer

Use calculated columns with complex logic

Question 3

You are building a Power BI data model from an Azure SQL Database. The source table contains a column 'OrderDate' of type datetime. You want to create a date table in Power Query that includes all dates from the minimum to maximum OrderDate. Which M function should you use to generate the list of dates?

Accepted Answer

List.Dates. `List.Dates` generates a list of sequential dates (type `date`) given a start date, a count of values, and a step duration. In Power Query, when you need a date table covering the range from the minimum to maximum `OrderDate`, you compute the count as `Duration.Days(MaxDate - MinDate) + 1` and use `List.Dates(MinDate, Count, #duration(1,0,0,0))`. This produces a clean list of dates without time components, ideal for a date dimension.

Answer

List.Generate

Answer

List.DateTimes

Answer

List.Range

Question 4

Which THREE of the following are best practices when designing Power BI reports for mobile devices? (Select three.)

Accepted Answer

Create a dedicated mobile layout view. Option A is correct because Power BI Desktop provides a dedicated Mobile Layout view (View > Mobile Layout) that lets you rearrange and resize visuals specifically for phone portrait orientation without affecting the desktop canvas. Option B is correct because small phone screens and varied lighting conditions make large font sizes and high-contrast colors essential for legibility and accessibility on mobile devices. Option D is correct because limiting each page to roughly 3-5 visuals keeps the mobile layout scannable and avoids excessive vertical scrolling and slow rendering on phones. Option C is not a mobile best practice per se: custom visuals are chosen for analytical capability, not for mobile optimization, and some custom visuals render poorly or are not optimized for small screens. Option E is not recommended because stacking multiple slicers consumes scarce screen space and complicates touch interaction; mobile designs typically favor a single, well-chosen slicer or filter pane instead.

Answer

Use custom visuals for advanced analytics

Answer

Include multiple slicers for flexible filtering

Question 5

You are designing a star schema for a sales analysis report. The source data includes Order Details, Products, Customers, and Dates. Which table should be the fact table?

Accepted Answer

Order Details. In a star schema, the fact table stores quantitative, measurable data (metrics) and foreign keys linking to dimension tables. Order Details contains sales transactions with measures like quantity and revenue, making it the correct fact table for sales analysis.

Answer

Dates

Answer

Customers

Answer

Products

Question 6

You have a table with columns 'Product', 'Category', and 'Sales'. You want to create a hierarchy that allows users to drill down from Category to Product. Which is the correct order to create the hierarchy?

Accepted Answer

Category -> Product. In Power BI, a hierarchy is built from the highest (most aggregated) level to the lowest (most granular) level. To allow drill-down from Category to Product, Category must be the top level and Product the child level. Option C correctly orders Category → Product, enabling users to expand from category-level totals to individual product sales.

Answer

Product -> Category -> Sales

Answer

Product -> Category

Answer

Sales -> Product -> Category

Question 7

You have a Power BI data model with a table 'Orders' that has columns: 'OrderID', 'OrderDate', 'CustomerName', 'Region', 'Product', 'Quantity', 'UnitPrice'. You want to create a measure that calculates total sales amount. Which DAX expression should you use?

Accepted Answer

Total Sales = SUMX(Orders, Orders[Quantity] * Orders[UnitPrice]). SUMX is an iterator function that evaluates the expression `Orders[Quantity] * Orders[UnitPrice]` for each row in the Orders table and then sums the results. This is necessary because DAX does not support direct multiplication of two columns inside SUM; SUM expects a single column reference, not an expression. SUMX performs row-by-row evaluation, which correctly computes the total sales amount as the sum of (Quantity × UnitPrice) across all orders.

Answer

Total Sales = COUNTROWS(Orders)

Answer

Total Sales = AVERAGE(Orders[Quantity]) * AVERAGE(Orders[UnitPrice])

Answer

Total Sales = SUM(Orders[Quantity] * Orders[UnitPrice])

Question 8

You are the Power BI administrator for a company that uses Microsoft 365. The security team requires that when a user opens a Power BI report on a personal device, the user must authenticate with Microsoft Entra ID and satisfy a conditional access policy that demands multifactor authentication. The report is in a workspace that is not backed by Fabric capacity. Which feature should you enable to meet this requirement?

Accepted Answer

Microsoft Entra ID Conditional Access. The requirement is to force MFA when users open a report on personal devices. Because Power BI authenticates users through Microsoft Entra ID, a Conditional Access policy that targets the Power BI app and requires MFA will enforce the challenge at sign-in. This works regardless of whether the workspace uses Fabric capacity. Other features like sensitivity labels, RLS, or Embedded do not enforce interactive MFA.

Answer

Power BI Embedded

Answer

Row-level security (RLS)

Answer

Sensitivity labels

Question 9

You have a Power BI model with a table 'Sales' and a related 'Product' table. You want to count the number of distinct products sold. Which DAX expression should you use?

Accepted Answer

DISTINCTCOUNT(Sales[ProductID]). DISTINCTCOUNT(Sales[ProductID]) returns the number of unique ProductID values in the Sales table, which directly answers the requirement to count distinct products sold. This function counts each distinct value in the specified column, ignoring duplicates, and is the standard DAX measure for distinct count calculations.

Answer

COUNTROWS(Sales)

Answer

COUNT(Sales[ProductID])

Answer

COUNTA(Sales[ProductID])

Question 10

You are importing data from a CSV file that contains a column 'OrderDate' with dates in the format 'MM/dd/yyyy'. Some rows have invalid dates like '02/30/2023'. What is the best way to handle these errors in Power Query?

Accepted Answer

Use 'Replace Errors' to replace error values with null.. 'Replace Errors' in Power Query allows you to replace error values (which occur when Power Query fails to convert an invalid date like '02/30/2023' to the Date type) with null. This preserves the rest of the data and keeps the query running without interruption, while clearly marking invalid entries for later handling or analysis.

Answer

Remove rows with errors using 'Remove Rows' > 'Remove Errors'.

Answer

Change the data type to 'Date' and ignore errors.

Answer

Filter the column to exclude rows where the date is invalid after type conversion.