The magnetic force can act on a charge, which is

The correct answer is Option (1) → moving in the perpendicular direction to the magnetic field

The magnetic force on a charge is

    \( \displaystyle F = qvB\sin\theta \)

where \( \theta \) is the angle between the velocity and the field. It is non-zero only when the charge is moving and its velocity is not parallel or antiparallel to the field.

Option (1) moving in the perpendicular direction to the magnetic field — Correct. Here \( \theta = 90^\circ \), so \( \sin\theta = 1 \) and the force is maximum, \( qvB \).

Option (2) moving in the direction of the magnetic field — Incorrect. Here \( \theta = 0^\circ \) and \( \sin 0^\circ = 0 \), so there is no force.

Option (3) moving in the direction opposite to the magnetic field — Incorrect. Here \( \theta = 180^\circ \) and \( \sin 180^\circ = 0 \), so there is no force.

Option (4) at rest — Incorrect. A charge at rest has \( v = 0 \), so a magnetic field exerts no force on it.

NCERT (2026-27):
Magnetic Field, Lorentz Force – “… (ii) The magnetic force \( q\,[\mathbf{v} \times \mathbf{B}] \) includes a vector product of velocity and magnetic field. The vector product makes the force due to magnetic field vanish (become zero) if velocity and magnetic field are parallel or anti-parallel. The force acts in a (sideways) direction perpendicular to both the velocity and the magnetic field.”

Magnetic Field, Lorentz Force – “… (iii) The magnetic force is zero if charge is not moving (as then \( |\mathbf{v}| = 0 \)). Only a moving charge feels the magnetic force.”