If we move an electron around the shell and around the solid sphere in a circular path, then what Is the work done for that motion?

The Earth moving round the sun in a circular orbit is acted upon by a force. What is the work done by the force?

In atom, an electron is revolving around the nucleus. What is the work done?

The motion of an electron around the nucleus cannot be determined accurately. Account for this statement.

According to Bohr atom model electrons are revolving in circular orbits around the nucleus. The movement of electrons can be regarded as a circular current flow. Then derive an expression for the magnetic dipole moment of an orbital electron.

A square ground has 2 metre wide path all around it. The total area of the ground and path is 1225 square metres. What is the area of the ground alone?