A) energy and momentum both remains constant
B) energy remains constant but momentum changes
C) both energy and momentum changes
D) energy changes but momentum remains constant
Correct Answer: B
Solution :
Key Idea: Perpendicular magnetic force exerted due to magnetic field provides the required centripetal force to the particle for motion on circular path. When a particle with charge q enters a magnetic field B, the force acting on it, is \[F=qvB\] This provides the centripetal force to the particle. \[qvB=\frac{m{{v}^{2}}}{R}\] Since,\[\overrightarrow{v}\]is perpendicular to \[\overrightarrow{B}\] the particle is acted upon by a force\[\overrightarrow{F}\]which is perpendicular to velocity, it does not change the magnitude of the velocity (speed) it changes only the direction of velocity. Hence, energy is constant but momentum changes.You need to login to perform this action.
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