Explanation

The force $F$ acting on a charged particle moving in a magnetic field is given by the Lorentz force equation, which can be expressed as:

$$F = q(mathbf{v} times mathbf{B})$$

Where:

• $\mathrm{<font\; color="\#0000ff"><b>F\; is\; the\; force\; acting\; on\; the\; particle,</b></font>}$
• $q$ is the charge of the particle,
• $mathbf{v}$ is the velocity vector of the particle,
• $\mathbf{B}$ is the magnetic flux density (magnetic field strength) vector.

The cross product $\mathbf{v}\times \mathbf{B}$ indicates that the direction of the force is perpendicular to both the velocity and the magnetic field vectors. Thus, the correct expression for the force is $F=qv\times B$.