[QUE/CM-05008]

Consider the motion in a spherically symmetric potential $$ V(r) = - V_0  \left( {3 R\over r } + {R^3\over r^3} \right)$$ If orbital angular momentum of the particle is given by $l^2 = 10 m V_0 R^2$, plot the potential as a function of $r$ and answer the following questions.

1. What is the minimum energy so that particle coming from infinity may fall to the center?
2. What should be the energy of the particle so that it may move in a circular orbit? Find the radius of the orbit.