Past exam of the physics 2 paper of the University of Oxford / 2018 / 9 / d / iii / Solution

When $\omega RC$ is of order one, the output consists of visibly curved exponential charging and discharging arcs, with neither long flat plateaus nor nearly straight sides. At $\omega RC=1$,The output is continuous and lags the abrupt input transitions; its precise shape is the periodic solution given in the parent part.