An electron in the ground state of hydrogen atom is revolving in anti-clockwise direction in the circular orbit of radius R as shown in figure.

The atom is placed in a uniform magnetic induction B such that the plane normal of the electron orbit makes an angle `30^(@)` with the magnetic induction. Find the torque experienced by the orbiting electron.

Answer

0.12

Explanation

Magnetic moment of electron,
M = `e/(2m_e)l`
=`e/(2m_e)(h/(2pi)) [ therefore l = h/(2pi)]`
= `(eh)/(4pirm)`
` vecR = oversetto(m) xx oversetto(B)`
`implies | vecr| = mB sin30^@`
= `((ehB)/(8pim))`
= 0. 125 `(ehB)/(pim)`
`therefore vecR = 0.12 (ehB)/(pim)`