What command would you use to find a file named 'test.txt'?

The command to find a file named 'test.txt' is effective because it leverages the 'find' utility, which is designed specifically for searching files and directories. When using 'find', you specify the starting directory (in this case, '/') and the criteria for the files you're searching for, like the name of the file in question. The '-name' option followed by 'test.txt' tells the system to look for files with that exact name starting from the root directory and traversing all subdirectories.

This approach is comprehensive as it searches through the entire filesystem, allowing the user to locate 'test.txt' regardless of its location. The 'find' command is powerful and suitable for cases where you need to locate files with specific names or patterns, thus making it an appropriate choice for this task. It’s especially useful if you're unsure of the file's location or if the file might reside in a nested directory structure.