This is a conversation close to my heart, and I'm glad to see it discussed.
However:
> 3. Yes, it adjusts the torque of the head
Is not, in my opinion, a good answer.
I would suggest "Yes, it limits the torque of the drill.", or even "Yes, it limits the amount of torque the drill applies to the bit." I would also remove #1 (or consider both #1 and #3 to be correct). Many users would think that is what is happening, and, quite frankly, it doesn't matter whether or not they know what's going on, under the hood.
The user's mental model is really important; much more important (IMNSHO), than the mental model of the developer. Discovering and reinforcing user mental models is a really important part of UX design (In my experience). I have found that it is better that I adapt to the user's mental model, than it is to force them to adopt mine.
However:
> 3. Yes, it adjusts the torque of the head
Is not, in my opinion, a good answer.
I would suggest "Yes, it limits the torque of the drill.", or even "Yes, it limits the amount of torque the drill applies to the bit." I would also remove #1 (or consider both #1 and #3 to be correct). Many users would think that is what is happening, and, quite frankly, it doesn't matter whether or not they know what's going on, under the hood.
The user's mental model is really important; much more important (IMNSHO), than the mental model of the developer. Discovering and reinforcing user mental models is a really important part of UX design (In my experience). I have found that it is better that I adapt to the user's mental model, than it is to force them to adopt mine.