Shown in the figure below is an infinitely long cylindrical shell of charge. The inner radius of the cylindrical shell is a and the outer radius is b. The shell carries a charge density p. There are three regions indicated in the figure and you will find the electric field in each of these regions. Region I Region II Region Ill (r>b) (b>r>a) (r a) . What is the formula for the USEFUL area of the Gaussian surface? A = . What is the formula for the charge inside? Qin = . What is the formula for the electric field? E = Region II: (within the cylindrical shell, b > r > a) . What is the formula for the USEFUL area of the Gaussian surface? A = . What is the formula for the charge inside? Qin = . What is the formula for the electric field? E =Region III: (inside the cylindrical shell, r