An electron moves with a speed of 5.0 × 10⁴ m/s perpendicular to a uniform magnetic field of magnitude 0.20 T. What is the magnitude of the magnetic force on the electron? (e = 1.60 × 10^-19C) A) 4.4 × 10^-14 N B) 1.6 × 10^-15 N C) 5 × 10^-20 N D) 2.6 × 10^-24 N E) zero

Question

Quizplus · Accepted Answer

The magnetic force on a moving charge is given by the equation F = qvBsinθ, where q is the charge, v is the velocity, B is the magnetic field magnitude, and θ is the angle between v and B. In this case, the electron is moving perpendicular to the magnetic field (θ = 90°), so sinθ = 1. Plugging in the given values with the charge of an electron (q = -1.6 × 10^-19 C), we get F = (-1.6 × 10^-19 C)(5.0 × 10^14 m/s)(0.20 T)(1) = -1.6 × 10^-15 N. However, since the electron is negatively charged, the direction of the force is opposite to the direction of motion, so we take the magnitude to be positive. Therefore, the magnitude of the magnetic force on the electron is 1.6 × 10^-15 N, which is closest to choice B, 1.6 × 10^-15 N.

An Electron Moves with a Speed of 5