A rectangular region of dimensions `wxxl (w ltlt l)` has a constant magnetic field into the plane of the paper as shown. On one side the region is bounded by a screen. On the other side positive ions of mass m and charge q are accelerated from rest and towards the screen by a parallel plate capacitor at constant potential difference `V lt 0`, and come out through a small hole in the upper plate. Which one of the following statements is correct regarding the charge on the ions that hit the screen ?

Options

A. Ions with `qgt(2|v|m)/(B^(2)w^(2))` will hit the screen.
B. Ions with `qlt(2|v|m)/(B^(2)w^(2))` will hit the screen.
C. Only ions with `q=(2|v|m)/(B^(2)w^(2))` will hit the screen.
D. All ions will hit the screen.

Answer

B