4. Assume that an observer calculates electric field and potential by measuring the force on a test charge. This observer moves along the path described by the green arrow. Finally, assume the system is in vacuum. (a) Plot | E | on a log-log scale for a charged sphere +Q enclosed off-center within an ungrounded spherical metal shell. Calculate the slope of this plot. (b) Draw all relevant field lines on the schematic (within reason). Hint: consider where the charges would be induced on the inner and outer surfaces of the shell. charged sphere enclosed inside ungrounded metal sphere In | E| + Q To In "