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Microsoft Power BI Data Analyst (PL-300): Practice Questions
Original practice questions for Microsoft Power BI Data Analyst (PL-300). Each answer is explained, including why each other option is wrong. Filter by domain or difficulty. These are concept checks - not questions from the certification.
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In Power BI, which tool do you use to clean and transform data before it loads into the model?
Correct answer: B. Power Query is the data-preparation engine where you clean, shape and combine data before loading. DAX is for calculations on data already in the model, not pre-load transformation; a slicer is a report control for filtering visuals; and row-level security restricts which rows users see, not how data is shaped. -
You need to combine two queries that have the same columns by stacking their rows into one table. Which operation do you use?
Correct answer: D. Append stacks rows from queries that share the same column structure into a single longer table. Merge joins queries side by side on a matching key (adding columns, not rows); Pivot turns row values into columns; and Group By aggregates rows into summary rows - none of which stack two same-shaped tables. -
A column imported as text contains values like "1,250" that should be numbers. The cleanest fix in Power Query is to:
Correct answer: A. Setting the correct data type in Power Query fixes it once, at the source, and the step replays on every refresh. Converting in each DAX measure is repetitive and fragile; deleting and re-typing by hand loses data and breaks on refresh; and hiding the column leaves the underlying type wrong, so calculations still fail. -
What does Column quality / data profiling in Power Query help you find?
Correct answer: D. Data profiling surfaces the share of valid, error and empty values (and distribution) so you can spot quality issues early. It does not write DAX, does not recommend chart types, and does not manage user access - those belong to modelling, report design and security respectively. -
The Power Query Editor records your transformations as a list of:
Correct answer: A. Each transformation is saved as an ordered Applied Step, and the whole sequence re-runs on every data refresh. DAX measures are model calculations, not Power Query steps; bookmarks save report-page states; and workspace roles control collaboration permissions - none of these record transformations. -
Removing rows that have errors in a column is a data-preparation task best done:
Correct answer: D. Power Query's Remove Errors strips problem rows before load, so the model only ever sees clean data. A DAX calculated column runs after load and cannot remove rows from the source; row-level security filters by user, not by data quality; and a slicer only filters the view, leaving the bad rows in the model. -
What is the purpose of the Merge queries operation in Power Query?
Correct answer: C. Merge joins a second query to the first on a matching key, adding its columns - similar to a SQL join. Stacking rows from identical tables is Append, not Merge; creating a visual happens in report view; and scheduling refresh is a service setting - none of these join tables on a key. -
In a Power BI data model, what does cardinality describe?
Correct answer: A. Cardinality defines the matching pattern of a relationship - one-to-many, one-to-one or many-to-many. The colour theme is a formatting choice; refresh frequency is a service schedule; and the number of visuals is a layout matter - none describe how rows relate across a relationship. -
DAX is the language used in Power BI to:
Correct answer: C. DAX (Data Analysis Expressions) builds calculated columns and measures over the data model. Connecting to sources is done in Power Query / Get Data; page layout is set in report view; and workspace permissions are configured in the service - none use DAX. -
Which best describes a measure in Power BI?
Correct answer: B. A measure is computed on demand at query time and responds to the current filter context, which suits aggregations like totals and ratios. A value stored row by row at refresh is a calculated column; a canvas filter is a slicer; and a refresh setting is a service option - none of these are measures. -
When should you prefer a measure over a calculated column for an aggregation like Total Sales?
Correct answer: B. A measure recalculates with the filter context (slicers, rows, page filters) and stores nothing extra, which is exactly what an aggregation needs. A calculated column stores a fixed per-row value and does not react to report filters; calculated columns are not created in Power Query (that is M); and the choice clearly matters for both correctness and model size. -
What is filter context in DAX?
Correct answer: C. Filter context is the combination of filters acting on a measure at evaluation time, which is why the same measure can show different numbers in different visuals. A visual's colour is formatting; Applied Steps belong to Power Query; and the user list is a workspace concern - none define how a measure is filtered. -
In a star schema, the table that stores the numeric events you want to analyse (such as individual sales) is the:
Correct answer: C. The fact table holds the transactional, numeric events (the measures you aggregate). A dimension table holds descriptive attributes like product or date; there is no standard 'slicer table'; and a slicer/visual is a report element, not a model table - so none of those store the events. -
A relationship's cross-filter direction set to Both means:
Correct answer: A. A Both (bidirectional) cross-filter lets filters propagate in both directions across the relationship, which is occasionally needed but can cause ambiguity. It does not disable the relationship, has nothing to do with how many reports use a dataset, and does not change refresh frequency. -
A CALCULATE-style time-intelligence measure such as year-to-date sales relies on the model having a:
Correct answer: D. Time intelligence needs a continuous date table (ideally marked as the date table) so functions can navigate periods. A slicer is just a filter control; a many-to-many relationship is a cardinality choice unrelated to dates; and a bookmark saves a report view - none of which give DAX the date dimension it requires. -
Why is a star schema generally preferred over a single flat table in Power BI?
Correct answer: C. Power BI's engine is tuned for star schemas, so models are smaller and DAX and relationships are cleaner. A star schema deliberately splits data into fact and dimension tables (not one table); it does not remove the need for DAX; and it has no effect on whether refresh works. -
On a report page, what does a slicer do?
Correct answer: B. A slicer is an on-canvas control that the viewer uses to filter the page's visuals. Cleaning data is a Power Query task; defining relationships happens in the model; and scheduling refresh is a service setting - none of these are what a slicer does. -
You want users to click a data point and jump to a page showing detailed rows for just that selection. Which feature is this?
Correct answer: A. Drill-through navigates to a detail page automatically filtered to the item the user selected. Append is a Power Query operation that stacks rows; row-level security restricts which rows a user can see at all; and scheduled refresh updates data on a timetable - none provide click-to-detail navigation. -
To compare a single value (such as total revenue) against a target at a glance, the most appropriate visual is usually a:
Correct answer: D. A card or KPI visual is built to show one headline number, optionally against a target. A scatter chart compares two numeric variables across many points; a map plots geographic data; and a wide matrix is for detailed cross-tabulation - none are the clean single-value display the question needs. -
What does a bookmark capture in a Power BI report?
Correct answer: B. A bookmark stores a specific page state - its filters, selections and which visuals are shown - so you can return to or present it later. It does not store the connection string (a data-source setting), does not hold DAX (that lives in the model), and does not control refresh timing. -
To analyse the relationship between two numeric variables, such as marketing spend versus sales, the most suitable visual is a:
Correct answer: C. A scatter chart plots two numeric measures on the X and Y axes, making correlations and outliers visible. A single card shows just one value; a slicer is a filter control, not an analysis visual; and a text box only displays static text - none reveal a two-variable relationship. -
Which visual is best for showing how a total breaks down into parts across categories and time, such as sales by region over months?
Correct answer: A. A stacked column or bar chart shows category contributions to a total and how they change across an axis like time. A single KPI card displays only one number; a slicer filters rather than displays a breakdown; and a button is a navigation element - none present a part-to-whole comparison. -
The Analyze / 'Explain the increase' and Key influencers features in Power BI help you:
Correct answer: B. These analytical features surface the factors that most drive a metric or its change, helping explain the 'why' behind the numbers. Scheduling refresh is a service setting; connecting to a source is a Get Data / Power Query task; and assigning roles is workspace administration - none perform this contributor analysis. -
Conditional formatting on a table or matrix visual lets you:
Correct answer: B. Conditional formatting drives cell background, font colour, data bars or icons from the underlying value, drawing the eye to highs and lows. Restricting rows by user is row-level security; merging queries is a Power Query operation; and marking a date table is a modelling step - none style a visual by value. -
In the Power BI service, a workspace is best described as a:
Correct answer: D. A workspace is a shared container where a team develops and manages reports, dashboards and datasets together. A DAX measure is a single calculation; a chart is one visual; and a Power Query transformation is a data-prep step - none are a collaboration space. -
Row-level security (RLS) in Power BI is used to:
Correct answer: C. RLS uses DAX filter roles so each user only sees the rows their role permits, while everyone opens the same report. It does not speed up refresh, does not pick visuals, and does not append tables - those are performance, design and Power Query concerns respectively. -
To keep a published report's data current from its source on a timetable, you configure:
Correct answer: A. Scheduled refresh updates the dataset from its source at set times so reports show current data. A slicer only filters the view; a calculated column adds a model field; and a bookmark saves a page state - none of these pull fresh data on a schedule. -
An on-premises data gateway is needed when you want to:
Correct answer: A. A gateway bridges the Power BI service to on-premises sources so scheduled refresh can reach data behind your firewall. Adding a KPI card is report design; writing a measure is modelling; and changing a data type is a Power Query step - none require a gateway. -
After defining row-level security roles in Power BI Desktop, where do you assign actual users to those roles for a published report?
Correct answer: B. You create RLS roles in Desktop but map real users or groups to them in the dataset's Security settings in the Power BI service after publishing. Power Query handles data prep; a bookmark saves a page view; and the format pane styles visuals - none assign users to security roles. -
Publishing a report from Power BI Desktop sends it to:
Correct answer: C. Publishing uploads the report and its dataset to a workspace in the Power BI service, where it can be shared and refreshed. It does not export to a local CSV, does not open the Power Query Editor (a data-prep tool), and is unrelated to printing.
Practice questions FAQ
- Are these real PL-300 exam questions?
- No. These are original study questions written to test understanding. They are not real exam questions, exam dumps, or copied from any provider.
- How should I use these practice questions?
- Answer each one, read the explanation (including why the wrong options are wrong), and use the per-domain score below to focus your revision on weak areas. Revisit before exam day.
- How many questions should I do before the exam?
- Enough to score consistently across every domain, alongside full-length practice from official or reputable providers. Understanding why each answer is right matters more than raw volume.
- What score means I am ready?
- A good signal is consistently scoring around 80% or higher across all domains on questions you have not seen before, and being able to explain why the wrong options are wrong.
- Should I use exam dumps?
- No. Dumps (real or leaked questions) breach provider policy, can void your certification, and do not build the understanding the exam actually tests.