Basic Power BI Interview Questions

1. What is Power BI?
Power BI is a business analytics service by Microsoft, and collection of software services, apps, and connectors that work together to turn your unrelated sources of data into coherent, visually immersive, and interactive insights. Your data may be an Excel spreadsheet, SharePoint or a collection of cloud-based, and on-premises hybrid data warehouses. We easily connect to data sources, visualize and share our analysis and insights with anyone you want.
Power BI contains several elements that all work together, starting with these three basics:
Power BI Desktop(Windows desktop application ).
Power BI service(An online SaaS (Software as a Service) service ).
Power BI mobile apps for Windows, iOS, and Android devices.

2. What is Power BI Desktop?
Power BI Desktop is a free Windows desktop application which can be installed on your own system. Power BI Desktop works cohesively with the Power BI service by providing advanced data exploration, shaping, modeling, and creating report with highly interactive visualizations. We can save our work to a file, or publish our data and reports right to Power BI site to share with clients.

3. How can we connect to any data sources in Power BI?
There are three main connectivity modes in Power BI(Import Files, Direct Query and Live Connection)
Import Files: Data can be imported from Excel (.xlsx, xlxs), Comma Separated Value (.csv) and Power BI Desktop files (.pbix).
Content Packs or Direct Query : It is a collection of related documents or files that are stored as a group. In Power BI, there are two types of content packs, firstly those from services providers like Google Analytics, Marketo, or Salesforce and secondly those created and shared by other users in your organization.
Live Connection or Connectors to databases like Azure Analysis Services, SQL Server Analysis and Power BI Datasets from Power BI Service etc.

4.What is a dashboard?
A dashboard is a single layer presentation sheet of multiple visualizations reports. The main features of the Power BI dashboard are:
It allows you to drill through the page, bookmarks, and selection pane, and also lets us to create various tiles, and integrate URLs
A dashboard can also help us to set report layout to mobile view.

5. What are the different views present in Power BI Desktop?
There are three views in Power BI(Report, Data and Relationship View)

6. what are the building blocks of Power BI.
Visualizations, Datasets, Reports, Dashboards, and Tiles.

7. Describe the main components of the Power BI toolkit, and explain briefly?
Power Query: Which lets us to discover, access, and consolidate info from different sources.
Power Pivot: It’s a modeling tool
Power View: It’s a presentation tool for creating charts, tables, etc..
Power Map: It’s lets us to create Geospatial representations of your data.
Power Q&A: It will be used to get answers to questions; for example, “What were the total sales in 2020–21?”

8. What is Visualization, Report, Dashboard, and Tiles?
Visualization is a visual representation of dataset that extracts information from the data based on the business.
Report is basically a collection of visualization charts that appear together on one or more pages within power BI.
Dashboard is single layer presentation sheet of multiple visualizations reports.
Tiles is basically a single visualization in a report or on a power BI dashboard.

9. Describe the different types of filters in Power BI Reports?
Visual-level Filters: Visual level filters works on only an individual/single visualization, reducing the amount of data that the visualization can see in power BI.
Page-level Filters: Visual level filters works on only an individual/single visualization, reducing the amount of data that the visualization can see in power BI.
Page-level Filters: Report level filters work on the entire report within power BI project. Filtering all pages and visualizations will include within the report.

10. What is Power Pivot?
Power Pivot used to analyze our data. It empowers users to import large scale of data from numerous data sources into a single Excel sheet for better users interface.

11. How can we create a dashboard?
First we have to upload a dataset, and then upload the dataset, create multiple reports together as an beautiful dashboard.

12. What is the language used in Power Query?
M-language is the language used in Power Query. It’s a new programming language developed to be user-friendly, case sensitive and it’s identical to other languages.

13. What is a Power BI Service?
Power BI Service is a cloud-based analytical solution means sharing and viewing the dashboards, and reports on cloud platforms.
Power BI Service versions are available in three different options such as Free, Pro, and premium. Power BI Service also known as “Power BI Workspace” “Power”, “Power BI Web Portal”, and “Power BI Site”.

14. Where the data is basically stored in Power BI and explain?
There are two areas in which data is stored in Power BI when we import from data sources that are called Fact and Dimension tables.
Fact Tables: A fact table stores Quantitative information for analysis purpose, and it is not possible to normalize in most of the situations.
Dimension table: This table is to store dimensions, and attributes that describe stored in a fact table.

15. What is a Power Query?
It is an ETL tool used to reconstruct, clean, and transform data with the help of initiative interfaces without writing a single line of code. It helps a user in the following ways.
Power query is capable of importing data from various sources such as databases, big data, files, Social media, etc.
We can construct data based on requirements by removing, and adding data.
We can Join and append data from various sources.

16. Can we use Power Query and SQL together?
We can use both together. A SQL statement can be used as a source of Power Query for making additional logical processing and this will help in ensuring that an efficient query is passed to the source, and avoids unnecessary complexities.

17. What are the operations which are frequently carried out in Power Query?
We can join to Various records sources and extract the required records, and Shape the statistics as per our need.
We can Create New columns.
Duplicate, Merge, Split, Rename the columns.
Replace the Columns values.
Pivot, and Transpose the columns.

18. What is the distinction between Measure and Dimension?
Generally we use a calculated column when we choose to consider every row and a measure is used when we want an aggregate.
Measures: The Measure are used to calculate aggregations such as Sum, Min, Max, Average & Count at the desk level. It is calculated at the time of the question which says that the Measures are no longer saved somewhere in the database or in the model. They truly exist.
Calculated Column: The Primary distinction between the measure and the calculated column in the Evaluation context. The Evaluation of a calculated columns is completed at the row degree the place as the comparison context of a measure is at the desk level.

19. Describe DAX.
DAX stands for Data Analysis Expressions. It’s a collection of functions, operators, and constants used in formulas to calculate and return values. In other words, it helps us to create new information from the data we already have.

20. What are the three fundamental concepts of DAX?
Syntax, Functions(arguments) and Context.

21. What are the calculation types in DAX?
Calculated measures and Calculated Columns.

22.What are the datatypes in Power BI?
Decimal Numbers & Whole Numbers
Date & Date time

Happy Learning !!! :)








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