Two isolated conducting spheres are separated by a large distance. sphere 1 has a radius of 20 cm and an initial charge 30 nc while sphere 2 has a radius of 60 cm and an initial charge 70 nc. a very thin copper wire is now connected to the spheres to allow charge to flow between them. how much charge will be transferred from sphere 2 to sphere 1? (note that the charge transferred can be positive, negative or zero