Which of the following figures represents a half-wave rectifier?

In a full-wave $P-N$ junction diode rectifier, a load resistance of $1500 \ \Omega$ is used. No filter is used. Assume each diode has a forward resistance $R_f = 10 \ \Omega$ and reverse resistance $R_r = \infty$. When a sinusoidal voltage with a peak amplitude of $30 \ V$ and frequency $50 \ Hz$ is applied, calculate the $D.C.$ power output and $A.C.$ power input respectively.

$A$ diode is connected to $220 \, V$ $(rms)$ $ac$ in series with a capacitor as shown in the figure. The voltage across the capacitor is..... $V$

When a sinusoidal $AC$ voltage is applied to a half-wave rectifier,the peak output voltage is $10 \ V$. The value of the $DC$ voltage in this output is .......

For the given electric voltage signal,the $dc$ value is......$V$.

$A$ full-wave rectifier supplies a load of $1 \ k\Omega$. The $a.c.$ voltage applied to the diode is $220 \ V_{rms}$. If the diode resistance is neglected,the value of the ripple voltage $(rms)$ is .... $V$.