Physics - Magnetism Question with Solution | TestHub

$\overrightarrow{\mathbf{V}}\perp \overrightarrow{\mathbf{B}}$ in region II. Therefore, path of particle is circle in region II. Particle enters in region III if, radius of circular path, $r>1$ or $\frac{mv}{Bq}>1$ or $v>\frac{Bql}{m}$ If $v=\frac{Bql}{m},r=\frac{mv}{Bq}=l$, particle will turn back and path length will be maximum as shown in figure in region II. If particle returns to region I, time spent in region II will be $t=\frac{T}{2}=\frac{\pi m}{Bq}$, which is independent of $v$. $\therefore$ correct options are (a), (c) and (d).