Question

Suppose a negatively charged particle is moving in the -y direction. In what direction must a magnetic field be oriented to cause a magnetic force acting in the +x direction?

Answer 1

in the magnetic field , the magnetic force is given by

vector F = q ( vector V x vector B )

here q = -e

vector F = - e ( vector V x vector B )

the direction of magnetic force is given by right hand rule

it states that for the positive charge particle the thumb of right hand point in the direction of velocity, and the fingurs in the direction of magnetic field , then the magnetic force is directed perpendicular to the right hand palm

here particle move in negative y- direction so we place our thumb in - y direction

and magnetic force acting in the + x direction so our right hand palm placed perpendicular to + x direction

then we get our fingurs direction is in the inner of the page which represent the direction of magnetic field

here negative charge particle are used so the the direction of magnetic field is out of the page

so the magnetic field is in positive z direction Ans