An electron revolving around, the nucleus. Who provided the centripital force.

An electron is moving round the nucleus of a H_2 atom in a circular orbit of radius r. The coulomb force F between the two is

An electron is revolving along a circular path of radius 1 À with a frequency (10^15) Hz. What is the associated magnetic moment?

A train runs along an unbanked circular track of radius 30 m at a speed of 54 km/h. The mass of the train is 106 kg. What provides the centripetal force required for this purpose - The engine or the rails? What is the angle of banking required to prevent- wearing out of the rail?

If suddenly the gravitational force of attraction between the earth and a satellite revolving around it becomes zero. What will happen to the satellite?

Two artificial satellites, one close to the surface and other away are revolving around the earth. Which of them has larger speed?

An electron circulates round the nucleus in a path of radius (5.1 x 10^-11) m at a frequency of (6.8 x 10^15) Hz. Calculate the magnetic field at the centre of the path.