A charged particle moves with constant velocity in a region where no effect of gravity is felt but an electrostatic field \(\vec{E}\) together with a magnetic field \(\vec{B}\) may be present. Then which of the following cases are possible ?
(A) \(\vec{E} \neq 0, \vec{B} \neq 0\)
(B) \(\vec{E} \neq 0, \vec{B}=0\)
(C) \(\vec{E}=0, \vec{B}=0\)
(D) \(\vec{E}=0, \vec{B} \neq 0\)
Ans: \((A, C, D)\)