For an electron moving in nth circular
orbit of radius rn, the total distance is the circumference of the orbit,
2prn Thus
FIGURE 12 8 A standing wave
is shown on a circular orbit
where four de Broglie
wavelengths fit into the
circumference of the orbit Rationalised 2023-24
Physics
302
2p rn = nl,      n = 1, 2, 3