Yes. Instructors can always see your video during live streams.
For students, only the instructor's stream is visible during class by default. This is to make it easier to focus on the lesson without becoming distracted by other students' videos. If the instructor calls on a student during class, that student's video and audio will become available to the all of the other participants while they are being called on. However, even when a student is not being called on, instructors can always see their students' video streams during class.