Stay tuned, in one's mind, and on one's mind

One of my students in class asked me the following questions:

1. Can " Stay Tuned" be used for watching TV as well?
2. What are the differences between "in my mind" and "on my mind"?

Thanks to the Longman Web dictionary that helped me with the answer to the questions that tasks my brain a bit.

1. "Stay tuned" can be used for watching or listening to the same television channel or radio station. Or, when you work on some project that is pending for more suggestions, you stay tuned with it.
   * The news anchor always says, "Stayed tuned. We will be right back after this (commercial break).
   
2. "in my mind " means you have some idea or thoughts saved "in" your brain.
   * I think I have a better picture in my mind.
   
3. on my mind
   a) Something on my mind means that I have been bothered by something happened to me or something makes me worry about.
   
   *He looked as if he had something on his mind.
   b) if something is on my mind, that is what I am thinking about:
   *There is a song by the name of "You are always on my mind." meaning "You are just the one I want" or "You are just what the doctor ordered." It never refers to that you bother me so much.