An electromagnetic flow meter is used to measure blood flow rates during surgery. Blood containing Na+ ions flows due south through an artery with a diameter of 0.40 cm. The artery is in a downward magnetic field of 0.25 T and develops a Hall voltage of 0.35 mV across its diameter.
(a) What is the blood speed (in m/s)?
(b) What is the flow rate (in m3 /s)?
(c) The leads of a voltmeter are attached to diametrically opposed points on the artery to measure the Hall voltage. Which of the two leads is at the higher potential?