The characteristic curve of an ideal $p-n$ junction diode is:

For the circuit shown in the figure,the equivalent resistance between points $A$ and $B$ for two cases $(i)$ $V_A > V_B$ and (ii) $V_B > V_A$ is $\qquad \Omega$ and $\qquad \Omega$ respectively. ($D_1$ and $D_2$ are ideal diodes)

Which of the following diodes is reverse biased?

$A$ semiconductor $X$ is made by doping a germanium crystal with arsenic $(Z=33)$. $A$ second semiconductor $Y$ is made by doping germanium with indium $(Z=49)$. The two are joined end to end and connected to a battery as shown. Which of the following statements is correct?

In a $p-n$ junction diode,the direction of diffusion current is from

Which one of the following represents a forward-biased diode?