Beam deflection in magnetic fields

Steps:

• Identify the beam as a charged particle entering uniform magnetic fields perpendicular to its velocity.
• Note that the Lorentz force causes circular deflection in the field, with direction by right-hand rule.
• Trace paths: straight line outside fields, curved arcs inside based on field direction (into/out of page).
• Match numbered paths to consistent deflection: path 3 enters first field curving left, path 6 continues curving right in second field.

Why D is correct:

• Paths 3 and 6 follow the Lorentz force law, F = q(v × B), producing oppositely directed curves in adjacent fields for a continuous beam trajectory.

Why the others are wrong:

• A: Paths 1 and 4 show no deflection, ignoring magnetic force.
• B: Paths 1 and 6 mix straight and curved inconsistently with field entry.
• C: Paths 2 and 5 curve in same direction, violating alternating field polarities.

Final answer: D