The Magnetic Force on a Charged Particle Moving at a Constant

Multiple Choice

The magnetic force on a charged particle moving at a constant speed in a uniform magnetic field will be halved when the angle between the velocity of the particle and the direction of the magnetic field changes from 25.0° to

A) 50.0°.
B) 12.5°.
C) 57.7°.
D) 12.2°.