What will happen if a collection of positive and negative charges are

What will happen if a collection of positive and negative charges are passed at a high speed through a magnetic field which is perpendicular to the direction of motion of the charges ? (Assume that both kind of charges are NOT going to recombine)

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Both kind of charges will stop moving

Positive charges and negative charges will separate out

Positive charges will stop but negative charges will continue moving uninterrupted

Both kind of charges will keep moving uninterrupted

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Answer is Wrong!

This question was previously asked in

UPSC NDA-2 – 2023

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When a collection of positive and negative charges are passed at high speed through a magnetic field perpendicular to their motion, the positive and negative charges will separate out.

The Lorentz force ($\vec{F} = q(\vec{v} \times \vec{B})$) acts on a moving charge in a magnetic field. The force is perpendicular to both the velocity ($\vec{v}$) and the magnetic field ($\vec{B}$). For positive charges, the force direction is given by the right-hand rule applied to $\vec{v} \times \vec{B}$. For negative charges (where $q$ is negative), the force is in the opposite direction. This difference in the direction of the force causes the positive and negative charges to be deflected in opposite directions, leading to separation.

This principle is utilized in devices like mass spectrometers or velocity selectors to separate charged particles based on their mass-to-charge ratio or velocity. The charges will move in curved paths, not stop or continue uninterrupted, as long as they are within the magnetic field.

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