* Please determine magnitude of the magnetic field of the Earth in Ames, and the ratio charge/mass of an electron (in a number) using the data provided. Then, compare ratio charge/mass of an electron with the accepted value. The electron accepted values are: charge= 1.6*10^-19 C and mass=9.1*10^-31 Kg.

By adjusting the anode voltage and the current in the coils, we can have the electron beam strike a particular pin (see figure 2); for that case, the diameter of the orbit is then known. The pins are coated with phosphor, a material which emits light when struck by the electrons. You may be able to use this feature to determine when the beam is centered on a pin. Filament Anode pin # 3 2 5 4 1 0.064 m 0.077 m Emerging electrons 0.089 m 0.102 m 0.114 m Note that these distances give you the diameter of the orbit, not the radius! In the experiment we performed, we chose different pairs of values of current and anode voltage so that the beam always hits pin #4: Current (A) Vanode (V) 1 2 3 4 5 6 7 8 9 4.25 3.75 3.47 3.15 2.82 2.52 78.0 60.5 50.4 40.4 32.1 25.1 Your goal is to use the above relation to determine the ratio charge/mass of an electron. Show all your measurements, calculations and conclusions below. You should also be able to determine the magnitude of the magnetic field of the Earth in Ames