Choose the correct waveform that can represent the voltage across R of the following circuit, assuming the diode is ideal one :

For a transistor $$\alpha$$ and $$\beta$$ are given as $$\alpha = {{{I_C}} \over {{I_E}}}$$ and $$\beta = {{{I_C}} \over {{I_B}}}$$. Then the correct relation between $$\alpha$$ and $$\beta$$ will be :

For a transistor in CE mode to be used as an amplifier, it must be operated in :

Four NOR gates are connected as shown in figure. The truth table for the given figure is :