A hydrogen atom is in ground state (n = 1). The magnetic field produced by revolving electron, at centre of atom is $$B_0$$. Atom is excited to state n = 4. According to Bohr model, the correct alternative(s) is/are

Magnetic field at centre of atom for (n = 4) becomes $$\frac{B_0}{64}$$

Energy absorbed by atom in going from (n = 1) to (n = 4) is 12.75 eV

Change in magnitude of angular momentum of electron is $$\frac{3h}{2\pi}$$

Assume that this excited atom (n = 4) is at rest and it makes transition to ground state (n = 1) in a single quantum jump of an electron, (Take mass of atom $$M_H = 1.67\times 10^{-27}$$ kg) the recoil speed of atom will be nearly $$v = 4.1$$ ms$$^{-1}$$