I don't get this question? Data Set IlI:Using the same accelerating voltage as in Data Set I, connect the green power supply to the"y-y" inputs of the tube. Observe and record what happens as you vary Va. Then, connect thegreen supply simultaneously to both "x-x" and "y-y" inputs. Observe and record what happens asyou vary Va. (For fun, you might play with different combinations of which inputs are connected to+ and - terminals of the power supply.) Measure the angle of the beam spot's motion across the gridas you vary Va.

Figure 2: Circuit Diagram O 6.4 AC Green Red . Blue Anode Cathode O O .Q Filament X-X Y-Y e Beam O Focus E3-3 EXPERIMENTAL PROCEDURE: Hook up the circuit shown in Figure 2 above with the 40 Volt (green) power supply connected to the "x-x" deflection plates. Set the red power supply to about 250 Volts and use the focus control to obtain a small dot on the tube face - the smaller the dot, the better. Now vary the setting on the green power supply and observe what happens. Rotate the plastic grid on the tube face so that the beam moves parallel to the "x-axis" of the grid. In your notebook, draw an 'x-y' grid with the same number of squares as on the plastic grid, so you can record positions of the spot. Be sure to note down the size of the squares on the plastic grid. BAD KARMA AND THE WRATH OF KHAN WILL DESCEND ON ANY WHO DARES TOUCH THE PLASTIC GRID WITH A PENCIL POINT!! (What would really happen is that other students would grumble for years hence about the mess you left them.) Data Set I: Keeping the accelerating voltage (red power supply) fixed, record the spot position with zero deflection voltage Va (green power supply section). Then, record the spot position for five "positive" values of Va and for five "negative" values of Va. ("Negative" of course means that you have interchanged the connections of the tube to the + and - terminals of the (green) power supply.) What you are doing here is changing the magnitude and direction of the electric field created between the "x-axis deflector plates" by the voltage Va. The larger we make Va, the larger is the electric field acting on the electron as it passes between the plates, and thus the larger the deflection of the electron trajectory. When we reverse the polarity of Va , we reverse the electric field direction and hence the direction of the deflection. Data Set II: Pick one value of Va from data set I to act as a fixed deflection voltage for this data set. Draw another picture of the grid in your notebook to record data. For each of three more values of the accelerating voltage (red supply), record the spot positions with Va set to zero and with Va set to the value you chose from Set