An Electromagnetic Flowmeter Is Useful When It Is Desirable Not $V = 2.88 \mathrm { mV }$

An electromagnetic flowmeter is useful when it is desirable not to interrupt the system in which the fluid is flowing (such as the blood in an artery during heart surgery) . Such a device is illustrated in the figure. The conducting fluid moves with speed v in a tube of diameter d. Perpendicular to this tube is a magnetic field B. A voltage V is induced between opposite sides of the tube due to the motion of the conducting fluid in the magnetic field. For a certain case, B = 0.120 T, d = 1.2 cm, and the measured voltage is $V = 2.88 \mathrm { mV }$ Determine the speed of the fluid.

A) 2.0 m/s
B) 11 m/s
C) 0.075 m/s
D) 1.1 m/s
E) 750 m/s