A charged particle would continue to move with a constant velocity in a region wherein,

Options

A. `E=0,B ne0`
B. `E ne0,B ne 0`
C. `Ene0, B=0`
D. `E=0,B=0`

Answer

A, B, D

Explanation

Here, force on chrged particle due to electric field `F_(E)=qE`.
Force on charged particle due to magnetic field `F_(m)=q(vxxB)`
Now, `F_(E)=` if `E=0 and F_(m)=0` if `sintheta=0` or `theta^(@)=0^(@)` or `180^(@)`.
Hence, `B ne0`.
Also, `E=0 and B=0` and the resultant force `qE=q(qxxB)=0`. in this case `Ene0` and `Bne0`.