A transistor is operated in common emitter configuration at V_C = 2 V such that a change in the base current from 100 $$\mu $$A to 300 $$\mu $$A produces a change in the collector current from 10 mA to 20 mA. The current gain is

For transistor action
(1)  Base, emitter and collector regions should have similar size and doping concentrations.
(2)  The base region must be vety thin and lightly doped.
(3)  The emitter-base junction is forward biased and base-collector junction is reverse biased.
(4)  Both the emitter-base junction as well as the base-collector junction are forward biased.

Which one of the following pairs of statements is correct?

The following figure shows a logic gate circuit with two inputs A and B and the output Y. The voltage waveforms of A, B and Y are as given.



The logic gate is

To get an output Y = 1 in given circuit which of the following input will be correct ?