http://link.aip.org/link/?AJP/65/726/1
46% of students surveyed got this question wrong, that means false.
A constant magnetic field never changes the speed magnitude of velocity? of a charged particle which moves in it. (Bagno & Eylon, 1997)

the analysis are:
a. Recitation of formula: field applies force, and force causes acceleration according to Newton’s second law of motion 40% of 46% who got it wrong
b. Blind substitution into formula 37
c. No reason 23



Using this applet, you can see the velocity does not change.
A constant magnetic field never changes the speed magnitude of velocity? of a charged particle which moves in it.
the answer is (true)

Bagno, E., & Eylon, B.-S. (1997). From problem solving to a knowledge structure: An example from the domain of electromagnetism. American Journal of Physics, 65(8), 726-736. doi: 10.1119/1.18642