Question

A charge q is moving in a magnetic field then the magnetic force does not depend upon
A. Charge
B. Mass
C. Velocity
D. Magnetic field

Answer 1

Hint: Lorentz’s law of force states that when a charged particle is moving in a region of the magnetic field, then due to interaction of the charge with the magnetic field there is force experienced by the moving charge.



Formula used:
\[\overrightarrow F = q\left( {\overrightarrow v \times \overrightarrow B } \right)\], here \[\overrightarrow F \]is the magnetic force acting on the charged particle of charge q moving with velocity \[\overrightarrow v \]in the magnetic field \[\overrightarrow B \]






Complete answer:
Let the mass of the particle is m and the charge is q.
If the magnetic field in the region is \[\overrightarrow B \] then the magnetic force acting on the particle which is moving with velocity\[\overrightarrow v \],
\[\vec F = q\left( {\vec v \times \vec B} \right)\]
Then the magnitude of the magnetic force acting on the charged particle moving in the magnetic field region is,
\[F = qvB\sin \theta \], here \[\theta \] is the angle made by the velocity with a magnetic field vector.
So, the magnetic force acting on the charge particle depends on;
- Charge on the particle
- Speed of the particle
- Magnetic field strength of the region
- The angle between the magnetic field and the velocity vector
Hence, the magnitude of the magnetic force acting on the particle is independent of the mass of the charged particle.
Therefore, the correct option is (B).


Note:The direction of the magnetic force on the charged particle depends on the nature of the charge but the magnitude of the magnetic force doesn’t depend on the nature of the charge on the particle.