question_answer

If the potential energy of two molecules is A  B given by \[U=\frac{A}{_{r}6}-\frac{B}{_{r}12,}\] then at equilibrium position, its potential energy is equal to :

A) \[\frac{{{A}^{2}}}{4B}\]                

B) \[\frac{{{B}^{2}}}{4A}\]

C) \[\frac{2B}{A}\]               

D) \[\frac{-B}{4A}\]