Question

1) A mass spectrometer was used in the discovery of the electron. In the velocity selector, the electric and magnetic fields are set to only allow electrons with a specific velocity to exit the fields. The electrons then enter an area with only a magnetic field, where the electron beam is deflected in a circular shape with a radius of 8.0 mm. In the velocity selector, E = 400.0 V/m and B = 4.7 x 10-4 T. The same value of B exists in the area where the electron beam is deflected. a) What is the speed of the electrons as they exit the velocity selector? b) What is the value of e/m of the electron? c) What is the accelerating voltage in the tube? d) How does the electron radius change if the accelerating voltage is doubled?

Answer 1