Which of the following logic gates is called as Universal gate?

Which graph shows correctly the temperature (T). dependence of resistivity $(\rho)$ of a semiconductor?

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