Question

the diagram provided shows a long, straight wire carrying current i within a region of uniform magnetic field. the magnetic force experienced by the wire is also indicated in the diagram, but the magnetic fields direction is not shown. given the information in the diagram, what must the direction of the magnetic field be? into the plane of the figure out of the plane of the figure downward upward none of the choices are correct

Explanation:

Step1: Recall the right - hand rule for magnetic force on a current - carrying wire

The magnetic force on a current - carrying wire is given by $\vec{F}=I\vec{L}\times\vec{B}$, where $I$ is the current, $\vec{L}$ is the length vector of the wire in the direction of the current, and $\vec{B}$ is the magnetic field. The direction of the cross - product $\vec{L}\times\vec{B}$ gives the direction of the force. Using the right - hand rule: point the fingers of your right hand in the direction of the current ($\vec{L}$) and curl them towards the magnetic field ($\vec{B}$), and your thumb will point in the direction of the force.

Step2: Apply the right - hand rule to the given situation

The current $i$ is downward and the force $\vec{F}$ is to the right. Point the thumb of the right hand in the direction of the force (right) and the fingers in the direction of the current (downward). Then, the direction in which the fingers curl is out of the plane of the figure, which is the direction of the magnetic field.

Answer:

out of the plane of the figure