The controlling force curves P, Q and R for a spring controlled governor are shown in the figure, where 𝒓𝟏 and 𝒓𝟐 are any two radii of rotation.

The characteristics shown by the curves are

Options :

1. P – Unstable; Q – Stable; R – Isochronous

2. P – Unstable; Q – Isochronous; R – Stable

3. P– Stable; Q – Isochronous; R – Unstable

4. P – Stable; Q – Unstable; R – Isochronous