The magnetic force on a charge $q$ moving with velocity $\vec{v}$ in a magnetic field $\vec{B}$ is

1. NCERT §4.2 (Magnetic Force): the Lorentz magnetic force is $\vec{F} = q\vec{v}\times\vec{B}$. 2. The cross product means $\vec{F}$ is perpendicular to BOTH $\vec{v}$ and $\vec{B}$. 3. Magnitude: $F = q v B \sin\theta$, where $\theta$ is the angle between $\vec{v}$ and $\vec{B}$. 4. Direction: by the right-hand rule (point fingers along $\vec{v}$, curl toward $\vec{B}$, thumb gives $\vec{F}$ direction for positive $q$; reverse for negative $q$). 5. Option A has wrong dimensions (mixing $qv$ and $\vec{B}$). Option B is the dot product (a scalar, not a force vector). Option D is gibberish dimensionally. _Source: NCERT Class 12 Physics Part 1, Ch 4, §4.2 (Magnetic Force, Eq. 4.4), p. 2–3._