Question

A blood flow meter measures a potential difference of 9.0

Answer 1

A)

Electric field in the blood is

                  E = V / d = ( 9.0*10^ 5 V ) / (10^ -3 m )

                                 = 9*10^2 V /m

Electric force

              F = Eq = ( 9*10^2 V /m ) ( 1.6*10^ -19 C) = 1.44*10^ -16 N

b)

           Electric force balances the magnetic force

                F = B q v

                v = F / B q   = ( 1.44*10^ -16 N ) / ( 1.6*10^ -19 C) (0.035 T)   = 2.57*10^4 m/s