This page has some selected quizzes for 5G NR. These were designed with 3GPP R15 in mind.
Please feel free to have your reading materials ready while attempting these quizzes.
They are designed to help you identify your own learning potential
The 5G cheatsheet can be a good resource too. (Goto menu -> cheatsheet)
This is a 5G NR quiz which has 60+ questions.
The information areas are mainly for NSA with RF Interface and 3GPP design criterias.
This is a 5G NR quiz which has 20 questions.
This deals with Standards and Design mainly