Question

A charged particle is moving along a magnetic field line. The magnetic force on the particle is

• A. Along its velocity
• B. Opposite to its velocity
• C. Perpendicular to its velocity
• D. Zero

Answer 1

Answer: (D)

Zero

Force on a charged particle in the magnetic field is
F =q(v × B )F→=q(v→×B→) or F=qvBsinθF=qvBsin⁡θ
Here, θ=0θ=0o i.e., vv→ is parallel to B

∴∴F=0