File types and associations in Intro to Computing - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a file extension?

A file extension is the part of a file name after the last dot (.) that tells the computer what type of file it is, like .txt for text files or .jpg for images.

beginner

Why do computers use file associations?

File associations help the computer know which program to use to open a file based on its extension, so when you double-click a file, it opens in the right app automatically.

beginner

Give an example of a common file type and its associated program.

A .docx file is usually associated with Microsoft Word or other word processors, so opening it launches that program to edit the document.

intermediate

What happens if a file has no extension or an unknown extension?

The computer may not know which program to use and might ask you to choose one, or it may not open the file at all.

intermediate

How can you change a file association on your computer?

You can change file associations in your computer's settings by choosing which program should open a certain file type by default.

What does the file extension .mp3 usually indicate?

A A video file

B A text document

C An image file

D An audio file

The .mp3 extension is commonly used for audio files like music or sound recordings.

If you double-click a file and it opens in the wrong program, what is likely the issue?

A The file association is incorrect

B The file is corrupted

C The file has no extension

D The computer is turned off

Incorrect file associations cause files to open in the wrong program.

Which of these is NOT a file extension?

A .pdf

B .exe

C document

D .jpg

File extensions always start with a dot; 'document' is not an extension.

What program would most likely open a file with the extension .xlsx?

A A spreadsheet program

B A photo editor

C A web browser

D A video player

.xlsx files are spreadsheet files usually opened by programs like Microsoft Excel.

What is the main purpose of file associations?

A To organize files in folders

B To link file types to programs that open them

C To compress files

D To delete files safely

File associations link file types to the programs that open them.

Explain what a file extension is and why it is important for computers.

Think about how your computer knows which program to use when you open a file.

Describe what file associations are and how they affect your experience when opening files.

Consider what happens when you double-click a file on your computer.

Practice

1. What does the file extension .mp3 usually indicate?

easy

A. A text document

B. An audio music file

C. A video file

D. A spreadsheet file

Solution

1. Step 1: Understand file extensions

   File extensions like .mp3 tell us the type of content inside the file.

2. Step 2: Match .mp3 to common usage

   The .mp3 extension is widely used for audio music files.

3. Final Answer:

   An audio music file -> Option B

4. Quick Check:

   .mp3 = audio file [OK]

Hint: Remember: .mp3 = music/audio file [OK]

Common Mistakes:

• Confusing .mp3 with video or text files
• Thinking .mp3 is a document format

2. Which of the following is the correct way to associate a .txt file with a text editor in Windows?

easy

A. Rename the file extension to .doc to open in the text editor.

B. Double-click the file and it will automatically open in the text editor without any settings.

C. Drag the file into the text editor icon without setting any association.

D. Right-click the file, choose 'Open with', then select the text editor and check 'Always use this app'.

Solution

1. Step 1: Understand file association process

   To associate a file type with a program, you must explicitly set it so the system knows which app to use.

2. Step 2: Identify correct method in Windows

   Right-clicking the file and choosing 'Open with' then selecting the app and checking 'Always use this app' sets the association correctly.

3. Final Answer:

   Right-click the file, choose 'Open with', then select the text editor and check 'Always use this app'. -> Option D

4. Quick Check:

   Set association via 'Open with' and 'Always use' [OK]

Hint: Use 'Open with' + 'Always use this app' to set associations [OK]

Common Mistakes:

• Assuming double-click sets association automatically
• Renaming file extensions incorrectly
• Dragging files without setting default app

3. If you double-click a file named photo.jpg on your computer, which program will most likely open it if the file association is set correctly?

medium

A. A spreadsheet application like Excel

B. A web browser

C. A photo viewer or image editor

D. A text editor

Solution

1. Step 1: Identify the file type from extension

   The .jpg extension indicates an image file, usually a photo.

2. Step 2: Match file type to default program

   Image files like .jpg open with photo viewers or image editors by default.

3. Final Answer:

   A photo viewer or image editor -> Option C

4. Quick Check:

   .jpg = image viewer/editor [OK]

Hint: .jpg files open with photo viewers by default [OK]

Common Mistakes:

• Choosing spreadsheet or text editor for image files
• Assuming web browser always opens images

4. You try to open a .pdf file but get an error saying no program is associated with this file type. What is the best way to fix this?

medium

A. Install a PDF reader and set it as the default program for .pdf files.

B. Rename the file extension to .txt and open with a text editor.

C. Delete the file and download it again.

D. Open the file with a spreadsheet application.

Solution

1. Step 1: Understand the error cause

   The error means no program is linked to open .pdf files on the computer.

2. Step 2: Fix by installing and associating a PDF reader

   Installing a PDF reader and setting it as default for .pdf files solves the problem.

3. Final Answer:

   Install a PDF reader and set it as the default program for .pdf files. -> Option A

4. Quick Check:

   Associate .pdf files with a PDF reader [OK]

Hint: Install and set default app for unknown file types [OK]

Common Mistakes:

• Renaming file extensions incorrectly
• Trying to open with wrong apps
• Deleting files unnecessarily

5. You have a folder with files: report.docx, data.csv, presentation.pptx, and notes.txt. You want to open all these files quickly with their correct programs. Which of the following best describes how file associations help you?

hard

A. File associations automatically open each file with the correct program when double-clicked, saving time.

B. You must manually choose the program every time you open a file.

C. File associations rename files to match the program names.

D. File associations convert files to a single format to open with one program.

Solution

1. Step 1: Understand what file associations do

   File associations link file types to programs so files open automatically with the right app.

2. Step 2: Apply to multiple file types

   When you double-click files like .docx, .csv, .pptx, and .txt, each opens in its correct program without manual selection.

3. Final Answer:

   File associations automatically open each file with the correct program when double-clicked, saving time. -> Option A

4. Quick Check:

   Associations = auto open correct app [OK]

Hint: File associations open files with correct apps automatically [OK]

Common Mistakes:

• Thinking you must always pick the program manually
• Believing associations rename or convert files