Question

A negative charge is moving across a rook from south to north. A magnetic field runs from East to west. In what direction is the magnetic force on the moving negative charge?
A. Toward the East
B. Toward the west
C. Toward the floor
D. Toward the ceiling

Answer 1

Answer:

The magnetic force on the moving negative charge is towards the ceiling.

Explanation:

The magnetic force acting on a wire is given by the relation as follows :

$F=q(v\times B)$

q is charged particle

v is velocity of charged particle

B is magnetic field

In this case, a negative charge is moving across a rook from south to north. A magnetic field runs from East to west.

q = -q

v =+j

B = -i

So,

$F=-q(vj\times B(-i))$

Since, $j\times i=-k$

So,

$F=q(v\times B)(-k)$

So, the magnetic force on the moving negative charge is towards the ceiling.