A charged particle of charge e and mass m is moving in an electric field E, and magnetic field B. Construct dimensionless quantities and quantities of dimension
When a charged particle is moving in both electric and magnetic field, the physical quantities can no help to construct dimensional quantity.
The necessary centripetal force is provided by the magnetic Lorentz forces when a charged particle is moving perpendicular to the magnetic field.
On simplifying the terms, we have
We know that
And
then dimensional formula of the angular frequency