Question

State whether the given statement is True or False :

The kinetic energy of a charged particle moving in a uniform magnetic field remains unchanged.

• A. True
• B. False

Answer 1

The correct option is A True

Magnetic force acting on the moving charged particle $F=q(v\times B)$

Thus magnetic force always acts in a direction perpendicular to the motion of the particle. Thus magnetic force does not do any external work on the particle i.e. $W=0$

From Work-energy theorem, work done $W=\Delta K.E$

$⟹$ $\Delta K.E=0$

Thus kinetic energy of a charged particle moving in a uniform magnetic field remains unchanged.