Question

In the operating room, anesthesiologists use mass spectrometers tomonitor the respiratory gases of patients undergoing surgery. Onegas that is often monitored is the anesthetic isoflurane (molecularmass =

3.06 10^-25 kg). In a spectrometer, a singly ionizedmolecule of isoflurane (charge = +e) moves at a speed of4.40 10³ m/s on a circular path that has aradius of 0.105 m. What is the magnitudeof the magnetic field that the spectrometer uses?
1 T

Answer 1

The magnetic force is given by

           F= mv²/r

And F = Bqv

        Bqv =mv²/r

    The magnetic field that the spectrometeris

             B = mv/(qr)

   Here m=3.06 10^-25 kg

           q = 1.6*10^-19C

            v = 4.40 10³m/s

            r = 0.105 m

Substitute the values.