A charged particle moves with a constant speed through a region where a uniform magnetic field is present. If the magnetic field points straight upward, the magnetic force acting on this particle
Will be strongest when the particle moves
A) upward at an angle of $45 ^ { \circ }$ above the horizontal.
B) straight upward.
C) in a plane parallel to Earth's surface.
D) straight downward.

Question

A charged particle moves with a constant speed through a region where a uniform magnetic field is present. If the magnetic field points straight upward, the magnetic force acting on this particle
Will be strongest when the particle moves 
A) upward at an angle of $45 ^ { \circ }$ above the horizontal.
B) straight upward.
C) in a plane parallel to Earth's surface.
D) straight downward.

Quizplus · Accepted Answer

The magnetic force on a charged particle moving in a magnetic field is given by the Lorentz force law, which includes the cross product of the velocity of the particle and the magnetic field. The force is maximized when the angle between the velocity vector and the magnetic field vector is 90 degrees, which corresponds to motion in a plane parallel to Earth's surface when the magnetic field is straight upward.

A Charged Particle Moves with a Constant Speed Through a Region