Q. The magnetic force acting on a charged particle of charge −2 μC in a magnetic field of 2 T acting in y direction, when the particle velocity is (2î + 3ĵ) × 10⁶ m s⁻¹, is:
A) 4 N in z direction
B) 8 N in y direction
C) 8 N in z direction
D) 8 N in −z direction
Explanation
[Solution from source] F⃗ = q(v⃗ × B⃗). Only the x component of velocity matters: (2 × 10⁶ î) × (2ĵ) = 4 × 10⁶ k̂. Multiplying by q = −2 × 10⁻⁶ C gives −8k̂ N, i.e. 8 N in −z direction. Ignoring the negative charge gives +z. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.