An electron beam projected along positive x-axis deflects along the positive y-axis. If this deflection is caused by a magnetic field, what is the direction of the field?

Explanation

To determine the direction of the magnetic field that causes an electron beam, projected along the positive x-axis, to deflect along the positive y-axis, we can follow these steps:

### Step 1: Understand the motion of the charged particle
The electron beam is moving along the positive x-axis. This means that the velocity vector \( \vec{v} \) of the electrons is directed along the positive x-direction.

### Step 2: Identify the direction of the force
The problem states that the electron beam deflects along the positive y-axis. This means that the magnetic force \( \vec{F} \) acting on the electrons is directed along the positive y-direction.

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