Question

An electron is moving in a circular orbit in a uniform magnetic field. Is the kinetic energy of the electron changing?

Answer 1

Answer:

kinetic energy does not change

Explanation:

you can use the formula for the kinetic energy of the electron and for the radius of the trajectory of an electron in a uniform magnetic field:

$E_k=\frac{1}{2}m_ev^2\\\\r=\frac{m_e v}{qB}$

me: mass of the electron

B: magnetic field

q: charge of the electron

r: radius

By doing v the subject of the formula and replace it in the expression for the kinetic energy you obtain:

$v=\frac{rqB}{m_e}\\\\E_k=\frac{1}{2}m_e(\frac{rqB}{m_e})^2=\frac{r^2q^2B^2}{2m_e}$

as youcan see, all parameters r, q, B and me are constant.

hence, the kinetic energy does not change