Find out the vlaue of 1 Bohr magneton. Givne `h = 6.62 xx 10^-34 J s, e = 1.6 xx 10^-19C and m _e = 9.1 xx 10^-31 kg`

How far apart should the two electrons be , if the force each exerts on the other is equal to the weight of the electron? Given that upsilon _) = 8.854 xx 10^-12 SI unit, e = 1.6 xx 10^19 C and m_e = 9.1 xx 10^-31 kg.

Calculate the ratio of electrostatic to gravitational force between two electrons placed at a certain distance in air. Given that m_e = 9.1 xx 10^31 kg, e = 1.6 xx 10^19C and G = 6.6 xx 10^17 N m^2 kg^-2

A current of 2.4 A flows through a wire of cross-sectional area 1.5 mm^2 . Find the current density in the wire. If the wire contains 8 xx 10^28m^-3 elecrtrons per unit volume calculate the average relaxation on time. Given that charge on electron = 1.6 xx 10^-19C and mass of electron =9.1 xx 10^-31 kg.