Problem 3 (15 points): a) In the lab "Charge to Mass Ratio of the Electron\

Problem 3 (15 points): a) In the lab "Charge to Mass Ratio ofthe Electron", you used an electron gun (CRT), a set of Helmholtz coils, and a phosphorescent screen to observe the trajectory of electrons, such as the one shown below (represented by a dashed line, coming in the from the left): Given this trajectory, what is the direction of the B field produced by the Helmholtz coils? Draw the force vector experienced by an electron at the star. Below, draw a possible curve if the electron gun potential is lowered. Below, draw a possible curve if the current through the coils is lowered. q Explain the two graphs you drew above using = b) In the first part of the lab, you recorded Iavg through the Helmholtz coils and the potential of the CRT while keeping the (x,y) coordinates constant. From your data, you could create the plot shown on the right. Which of the following describes the plot: (Choose one) a. Bvs. I/R b. Bvs.V c. R vs. I