1. Electrostatic force between electron and the nucleus.
2. Vectorially
\(\overrightarrow \mu_1=\frac{-e}{2m_e}\overrightarrow I\)
The magnetic moment of the electron is opposite in direction to the angular momentum.
∴ Angle = 180°.
3. Revolving charge behaves as a current loop. Hence Magnetic field is given as
B = \(\frac{\mu_0}{2}\frac{1}{a}\)
I = \(\frac{q}{T}\) = qv = 2 × 10-3 × 100 = 0.2 A
Magnetic moment = IA = 0.2 × π × 0.152 = 0.0141 Am.