The given plot shows the variation of U, the potential energy of interaction between two particles with the distance separating them r,

Options

A. (a) B and D are equilibrium points
B. (b) C is a point of stable equilibrium
C. (c) The force of stable equilibrium between the two particles is attracive between points C and D and repulsive between D and E .
D. (d) The force of interaction between particles is repulsive between points E and F.

Answer

C

Explanation

At C, potential energy is minimum. So, it is stable equilibrium position.
`F=-(dU)/(dr)=-("Slope of U-graph")`
Negative force means attraction and positive force means repulsion.