Question

Potential energy curve is shown in figure. Point at unstable equilibrium is :

• A. $x=6$
• B. $x=4$
• C. $x=2$
• D. $x=3$

Answer 1

The correct option is C $x=2$

In potential energy curve, the points at maximum (i.e. at crest) are the points of unstable equilibrium since, the displacement of particle towards left or right will experiences the increase or decrease in the force and potential energy, both are related by the relation,
$F=-\frac{\delta U}{\delta x}$
Hence,
Point at unstable equilibrium is x=2.