According to Bohr's theory, the time averaged magnetic field at the centre (i.e., nucleus) of a hydrogen atom due to the motion of electrons in the n t h orbit is proportional to: ( n = principal quantum number)

Step-by-step solution

v ∝ z n r ∝ n 2 z B = μ I 2 R I = e T = e ( 2 π R v ) = e 2 π v R B = μ 0 2 e 2 π v R 2 B = μ 0 e 4 π z n ( n 2 z ) 2 B = μ 0 e 4 π z 3 n 5 B ∝ n − 5 .