AP® Physics C: E & M

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Overlapped Electric and Magnetic Fields

APPHEM-QUUY2N

A particle of charge $q$ and mass $m$ is moving in a circle of radius $2r$ in a uniform magnetic field of strength $B$.

Which of the following is a correct relationship for the magnitude of an Electric Field $E$ that would cause the charge to move in a straight line at a constant speed?

A

${vB}$

B

${E=\dfrac{rqB^2}{m}}$

C

${E=\dfrac{2rqB^2}{m}}$

D

${E=\dfrac{4rqB^2}{m}}$

E

${E=\dfrac{2rqB}{m}}$