Physics · Magnetism and Electromagnetic Induction

The hydrogen atom, which is effectively a proton in this context since it has lost its electron, is moving east in a magnetic field directed from south to north. To find the direction of the magnetic force acting on the proton, we can use the right-hand rule. For a positive charge like a proton, point your right thumb in the direction of the velocity (east), and your fingers in the direction of the magnetic field (north). The direction in which your palm pushes will indicate the direction of the magnetic force, which is upwards in this case. Therefore, the correct answer is up.

Option B (down) is incorrect because the right-hand rule does not support this direction. Option C (north) is incorrect as the force does not act along the direction of the magnetic field but rather perpendicular to it. Option D (south) is also incorrect for the same reason; the magnetic force is not directed south based on the right-hand rule.

This is correct. According to the right-hand rule, if you point your thumb in the direction of the velocity (east) and your fingers in the direction of the magnetic field (north), your palm will face up, indicating that the magnetic force acts upwards.

This is incorrect. When using the right-hand rule, the magnetic force does not point downward; instead, it points in the opposite direction to what is suggested here.

This is incorrect. The magnetic force on the charged particle does not act in the north direction. The right-hand rule indicates a different direction based on the given parameters.

This is incorrect. The magnetic force does not act southward when applying the right-hand rule in this scenario.