Do we get to know the results if we passed or failed immediately after the certification exam?
no, you will only know the result after 24-36hrs
Regarding the Linux foundation organisation:
" Our records show you recently completed the CKA Exam. A score report will be emailed to you, within 36 hours of completing the exam, and will also be available to you in your https://trainingportal.linuxfoundation.org/learn/dashboard/|Portal.
If you do not receive your score report after 36 hours, or you do not see your exam results in your https://trainingportal.linuxfoundation.org/learn/dashboard/|Portal, please login to http://trainingsupport.linuxfoundation.org|trainingsupport.linuxfoundation.org and submit the information requested. "