If the internal resistance of cell is negligible then current flowing through the circuit is

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)