Q: A charged particle (mass m charge q) moves along X-axis with velocity vo . When it passes through origin it enters a region having uniform electric field $\vec{E} = -E\hat{j}$ which extends up to x = d . Equation of path of electron in the region x > d is
(a) $\displaystyle y = \frac{q E d}{m v_o^2}(x-d)$
(b) $\displaystyle y = \frac{q E d}{m v_o^2}(\frac{d}{2}-x)$
(c) $\displaystyle y = \frac{q E d}{m v_o^2} x $
(d) $\displaystyle y = \frac{q E d^2}{m v_o^2} x$
Ans: (b)