Define the term: magnetic dipole moment of a current loop. Write the expression for the magnetic moment when an electron revolves at a speed v around an orbit of radius r in hydrogen atom.

Explanation

A current carrying loop behaves as a system of two equal and opposite magnetic poles separated by a distance. Hence it behaves as a magnetic dipole. Magnetic dipole moment of current loop is the product of current I and area A enclosed by the loop of current, i.e.
`M=IA=e/Txxpir^2=(e)/(2pir//v)xxpir^2=(evr)/(2)`
In a hydrogen atom, when an electron revolves at a speed v around an orbit of radius r, the magnetic moment is given by
`M=n((eh)/(4pim))`
where e is charge on electron, m is mass of electron, n denotes the number of orbit and h is Plack's constant.