No the teacher will not be informed. As Google Form has no such functionality. However schools may choose to use 3rd party apps such as autoproctor which integrate with Google Form to provide such a monitoring facility.

Can Google meet detect cheating?

As an app, Google Meet cannot detect cheating in exams or tests because it is designed for conducting online meetings. However, the app allows instructors to view students' movements through the camera.

Can Google Forms tell if you switch tabs?

Students can't open other browser tabs. The teacher will be notified via email if a student exits the quiz, or opens any other tab.