Question

A particle of mass m and charge $- q$enters the region between the two charged plates initially moving along x – axis with speed $v_{x}$as shown in figure. The length of plate is L and a uniform electric field E is maintained between the plates. The vertical deflection of the particle at the far edge of the plate is

• A. $\frac{qEL^{2}}{2mv_{x}^{2}}$
• B. $\frac{qEL^{2}}{2mv_{x}}$
• C. $\frac{2mv^{2}x}{qEL^{2}}$
• D. $\frac{2mv_{x}}{qE^{2}L}$

Answer 1

Answer: (A)

$\frac{qEL^{2}}{2mv_{x}^{2}}$

Answer 2

When the pint is on the diameter and away from the centre of hemisphere which is charged uniformly and positively, the component of electric field intensity parallel to the diameter cancel out. So the electric field is perpendicular to the diameter.