For a positively charged particle moving in a $x-y$ plane initially along the $x$-axis, there is a sudden change in its path due to the presence of electric and/or magnetic fields beyond $P$. The curved path is shown in the $x-y$ plane and is found to be non-circular. Which one of the following combinations is possible

An $e^-$ is moving parallel to a long current carrying wire as shown. Force on electron is

A proton moving with a constant velocity, passes through a region of space without change in its velocity. If $E$ $\& B$ represent the electric and magnetic fields respectively, this region may have

Two charged particles traverse identical helical paths in a completely opposite sense in a uniform magnetic field $B$ = $B_0\hat{k}$

A charged particle is released from rest in a region of uniform electric and magnetic fields which are parallel to each other. The particle will move on a