1. 19. For the R-C low-pass filter in Fig. 22.105: 1. Sketch Av = Vo/Vi versus frequency using a log scale for the frequency axis. Determine Av = Vo/Vi at 0.1fc, 0.5fc, 2fc and 10fc. 2. Sketch the phase plot of 0 versus frequency, where 0 is the angle by which V, leads V;. Determine 0 at f = 0.1fc, 0.5fc, fc, 2fc, and 10fc. Vi R ww 2.2 ΚΩ ā C · 0.02 με