Question
In CGS units, this quantity is “q B over m c,” which is derived from equating the centripetal and Lorentz forces. For 10 points each:
[10m] Name this quantity that arises from the circular motion due to a constant, orthogonal magnetic field.
ANSWER: cyclotron frequency [accept gyrofrequency; prompt on frequency]
[10e] The magnetic part of the Lorentz force does [emphasize] not include this quantity, which is multiplied by charge to get the Coulomb force. In most E&M formulas, this quantity is symbolized E.
ANSWER: electric field
[10h] Under the gauge assumption that the y operator is absent, name these two Hermitian operators that, along with the cyclotron frequency, is used to construct the Hamiltonian of the Landau levels.
ANSWER: p-sub-x and p-sub-z [accept any description of the momentum operator acting on both the x and z directions; accept px and pz; accept p-sub-x squared and p-sub-z squared; prompt on momentum operators; prompt on partial answer] (The operator p-sub-y is replaced by its eigenvalue due to conventional choice of gauge.)
<Ezra Santos, Physics>
Summary
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