$A$ diode is used as a/an

The frequency of a given $AC$ signal is $N \ Hz$. When it is connected to a half-wave rectifier,the number of output pulses given by the rectifier in $1 \ s$ is:

Explain the use of a junction diode as a full-wave rectifier by drawing a circuit diagram and show the input and output waveforms.

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

In the circuit shown in the figure, the maximum output voltage $V_0$ is.....$V$.

In a half-wave rectifier using a $PN$ junction diode, the input voltage has an amplitude of $25 \ V$ and a frequency of $50 \ Hz$. No filter is used, and the load resistance is $1000 \ \Omega$. The forward resistance of the diode is $10 \ \Omega$. The efficiency of the rectifier is approximately ...... $\%$.