Question

. An ion with a charge of +1 is trapped in the earth's magnetic field. It suddenly picks up 2 electrons, and its charge becomes -1. How does its motion change? Assume the gain of the 2 electrons does not involve a mechanical force. point) O It reverses direction along the same spiral path. O It travels along the same spiral path at a greater speed. O It travels along the same spiral path at a lesser speed. 0 The rotation of its spiral path reverses direction.

Answer 1

The force on a charge particle having charge ' q ' moving with a velocity ' v ' in a magnetic field ' B ' and electric field ' E ' is given by

$\vec{F} = q \vec{E} + q (\vec{v} \times \vec{B})$

if we change the polarity of charge then the direction of rotation of the charge (on the spiral path) will be reversed.

Hence, it will reverse the direction on the same spiral path.