In an n-p-n transistor amplifier, the collector current is 8 mA . If $80 \%$ of the electrons from the emitter reach the collector, then ( $\alpha$ and $\beta$ are current ratios)

In an n-p-n transistor amplifier, the collector current is 9 mA . If $90 \%$ of the electrons emitted reach the collector, then

The resultant logic gate from the combination of following gates is

In the following circuit shown in figure, three diodes are connected each with forward resistance $40 \Omega$ and infinite backward resistance. The current through $100 \Omega$ resistance is