Form the Bohr's theory, Speed of an electron in nth orbit, v∝n…(1) Radius of the orbit, r∝n2…(2) Time period, T=v2πr2π is a constant. Hence T∝vr… (3) From (1),(2) and (3)T∝n1n2⇒T∝n3 Angular speed, ω=T2π⇒ω∝n31 Hence, The angular speed of the electron in nth orbit of Bohr hydrogen is inversely proportional to n3