Q. In a Hartnell governor, the stiffness of the spring is given by (where S1 and S2 = Spring forces exerted on the sleeve at max. and min. radii of rotation and h = Compression of the spring)

• (A) S1+S2 h
• (B) S1−S2 h
• (C) S1+S2 2h
• (D) S1−S2 2h