Question

if charge moves toward North and magnetic field is towards East , find the direction of force.

1 point

out of plane

into the plane

towards right

towards left​

Answer 1

Given:

Charge moves toward North and magnetic field is towards East.

To find:

Direction of force?

Calculation:

We will try to do this problem with vector (refer to diagram):

Velocity of charge is :

$\rm \vec{v} = v( - \hat{k})$

Magnetic field Intensity :

$\rm \vec{B} = B( \hat{i})$

Now, force is given as :

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

$\rm \implies\vec{F} = q( - v \hat{ k} \times B \hat{i})$

$\rm \implies\vec{F} = qvB( - \hat{j})$

So, force is downwards (i.e. into the plane)