In a velocity selector, the uniform magnetic field of 1.5 T is produced by a large magnet. Two parallel plates with a separation of 1.5 cm produce the perpendicular electric field. What voltage should be applied across the plates so that:
a) A singly ionized ion traveling 8.0 x 104 m/s will pass through undeflected.
b) A double ionized ion traveling at the same speed will pass through undeflected.