Question

A charge is moving in a magnetic field that points to the left.

What direction can the charge move and experience no magnetic force? Check all that apply.

up
down
left
right
into the screen
out of the screen

Answer 1

To determine the direction in which a charged particle can move without experiencing a magnetic force, we can use the right-hand rule. According to the Lorentz force law, the magnetic force on a moving charge is given by the equation:

\[
\vec{F} = q (\vec{v} \times \vec{B})
\]

where:
- \(\vec{F}\) is the magnetic force,
- \(q\) is the charge,
- \(\vec{v}\) is the velocity of the charge,
- \(\vec{B}\) is the magnetic field.

In this scenario, the magnetic field (\(\vec{B}\)) points to the left. For there to be no magnetic force (\(\vec{F} = 0\)), the velocity vector (\(\vec{v}\)) must be parallel or antiparallel to the magnetic field vector (\(\vec{B}\)).

### Directions:
- **Up:** Not parallel to the left direction (therefore, there will be a magnetic force).
- **Down:** Not parallel to the left direction (therefore, there will be a magnetic force).
- **Left:** Parallel to the magnetic field (this direction will result in no force).
- **Right:** Not parallel to the left direction (therefore, there will be a magnetic force).
- **Into the screen:** Not parallel to the left direction (therefore, there will be a magnetic force).
- **Out of the screen:** Not parallel to the left direction (therefore, there will be a magnetic force).

### Conclusion:
The charge can move **left** to experience no magnetic force. Other directions will result in a magnetic force being exerted on the charge.