On Fig. 11.1, circle any diodes that conduct when terminal $X$ of the input is positive relative to terminal $Y$.
Mark the positive $(+)$ terminal and the negative $(-)$ terminal of output $AB$.
The potential difference $V$ across input $XY$ varies with time $t$ according to $V = 5.6\sin 380t$, where $V$ is in volts and $t$ is in seconds. Use the expression for the input potential difference $V$, or another method, to find the root-mean-square (r.m.s.) potential difference $V_{\text{r.m.s.}}$ of the input.
Find how many times each second the rectified potential difference at the output reaches a peak value.
A capacitor is then connected between the output terminals $AB$. The capacitor reduces the output variation (the ripple) to $1.6\,\text{V}$. On Fig. 11.2, sketch how the smoothed output voltage varies with time $t$ for $t = t_1$ to $t = t_2$.
Suggest and explain, if there is any effect, on the mean power dissipation in resistor $R$ when the capacitor is connected between terminals $AB$.
A capacitor is then connected between the output terminals AB. The capacitor reduces the output variation (the ripple) to $1.6\,\text{V}$.