Physics

Problem

Two identical ions, each of charge

+q

, move through vacuum with the same speed

v

. • For ion 1 you measure the magnetic field magnitude

B_A

at point A, located directly to the side of its path so that the angle between

\vec v

and

\vec r

90^{\circ}

. • For ion 2 you measure the magnetic field magnitude

B_B

at point B, located directly behind the ion along its line of motion, so the angle between

\vec v

and

\vec r

180^{\circ}

. Which statement correctly compares

B_A

and

B_B

? a)

B_A < B_B

B_A = B_B

B_A > 0 \text{ and } B_B = 0

B_A = 0 \text{ and } B_B > 0