Question

The force acting on a body moving along $x$-axis varies with the position of the particle as shown in the figure. The body is in stable equilibrium at

• A. $x=x_1$
• B. $x=x_2$
• C. both $x_1$ and $x_2$
• D. neither $x_1$ nor $x_2$

Answer 1

Answer: (B)

When particle moves away from the origin, then at position $x=x_1$, force is zero and at $x>x_1$, force is positive (repulsive in nature). So particle moves further and does not return back to original position, i.e., the equilibrium is not stable.
Similarly, at position $x=x_2$, force is zero and at $x>x_2$, force is negative (attractive in nature).
So, particle returns back to original position, i.e., the equilibrium is stable.