An electron moves with a speed of 3.0 × 10⁴ m/s perpendicular to a uniform magnetic field of 0.40 T. What is the magnitude of the magnetic force on the electron? A) 4.8 × 10^-14 N B) 1.9 × 10^-15 N C) 5 × 10^-20 N D) 2.2 × 10^-24 N E) zero

Question

Quizplus · Accepted Answer

The magnitude of the magnetic force on a charged particle moving perpendicular to a magnetic field is given by F = qvB, where q is the charge of the particle, v is its velocity, and B is the magnetic field strength. In this case, the charge of the electron is -1.6 x 10^-19 C and its velocity is 3.0 x 10^6 m/s. Therefore, the magnetic force on the electron is F = (-1.6 x 10^-19 C)(3.0 x 10^6 m/s)(0.40 T) = -1.92 x 10^-14 N, which has a magnitude of 1.9 x 10^-15 N (since force is a vector quantity and can point in different directions, we take the magnitude of the force). Therefore, the correct answer is (B).

An Electron Moves with a Speed of 3