The potential energy of a particle in a force field is:
`U = (A)/(r^(2)) - (B)/(r )`,. Where `A` and `B` are positive
constants and `r` is the distance of particle from the centre of the field. For stable equilibrium the distance of the particle is

Options

A. `B//2A`
B. `2A//B`
C. `A//B`
D. `B//A`

Answer

B

Explanation

(b) Given, the potential energy of a particle in a force field
`U=(A)/(r^(2))-(B)/(r )`
For stable equilibrium, `F=-(dU)/(dr)=0`
`o=-(2A)/(r^(3))+(B)/(r^(2))" or "(2A)/(r )=B`
The distance of particle from the centre of the field
`r=(2A)/(B)`