For an ideal diode, in forward and reverse biased condition the resistance is respectively

When an n-p-n junction transistor is used as an amplifier in common emitter mode,

In a transistor (common emitter configuration) the ratio of power gain to voltage gain is ( $\alpha$ and $\beta$ are current ratios)

In a given logic circuit, the output Y when all the three inputs $\mathrm{A}, \mathrm{B}, \mathrm{C}$ are first low and then high will be respectively