The double reed on an oboe produces the sound through vibrations when air is blown through it. Moving the keys produces different pitches and notes
the slide can extend to produce a lower pitch, and it can also retract to produce higher pitches. all brass instruments can also produce different notes by tensing up the lips (higher notes) or by relaxing the lips (lower notes).
the different lenghts play different pitches or notes, the longer the string, the lower the note.
The only way pitches can be produced on a trumpet is through the vibrating lips of the player. That player can change the pitches by either changing their embouchure or by changing which valves are depressed.
Yes, the octaves are the same notes but in varying pitches.
By varying their tension, tighter = higher pitch.
The clarinet can be pitched at different pitches when you play low to high notes
All saxophones have the same fingerings, the notes just come out at different pitches :)