Correct Answer - Option 4 : A neutron moving in a magnetic field
CONCEPT:
Magnetic field (B):
- The region or space around a current-carrying wire or around a magnet in which magnetic force can be experienced by other magnets is called a magnetic field.
- When a moving charged particle enters a magnetic field then the path followed by the charged particle is circular if the magnetic field is perpendicular to the velocity of the particle.
- While moving through a magnetic field, the charged particle experiences a force.
- This force is given by the charge times the vector product of velocity and magnetic field.
\(F = q (\vec{v}\times \vec{B})\)
where q is the charge on particle, v is perpendicular velocity and B is the magnetic field.
EXPLANATION:
- According to the above discussion, it is clear that the magnetic force can act only on moving charged particles, magnets, and current element.
- So there will be a magnetic force on electrons, protons, and alpha particles. Because they have a charge and they are moving.
But for a neutron, q = 0
\(F = q (\vec{v}\times \vec{B}) = 0\)
- Thus a neutron moving in a magnetic field will not experience any magnetic force.
