# A conductive sphere of radius r is given a charge Q. Another sphere of radius R is put in contact with it.They are separated after they have shared a charge. assuming that the spheres are held at fixed distance apart, what should be the value of R so that the force between two charged spheres is the maximum?..if u can help me out!

Dear Student,

Potential of the first sphere and second sphere after the charge distribution are,

When these two spheres are kept in contact, then the potential of the two spheres should be same. Therefore,

The total charge will be

Therefore, when the two charges are placed at a distance "d", then the force of repulsion between them is,