Ubuntu Linux Remove/Delete PPAs apt-get command

Originally published at: https://www.cyberciti.biz/faq/howto-remove-remove-delete-ppas-using-apt-get-command-on-ubuntu/

Over time I have added way too many PPAs using the add-apt-repository command on Ubuntu Linux 16.04/18.04 LTS server for testing purpose. How can I delete or remove those PPAs? Is there a command to list all PPAs?