In the figure shown, the npn transistor acts as a switch.

For the input v_in(t)as shown in the figure, the transistor switches between the cut-off and saturation regions of operation, when T is large. Assume collector-to-emitter voltage saturation V_CE(sat) = 0.2V and base-to-emitter voltage V_BE = 0.7V. The minimum value of the common-base current gain$$\left( \alpha \right)$$ of the transistor for the switching should be _________.

The amplifier circuit shown in the figure is implemented using a compensated operational amplifier (op-amp), and has an open-loop voltage gain, A₀ 10⁵ V/V and an open-loop cut-off frequency, f_C = 8 Hz. The voltage gain of the amplifier at 15 kHz, in V/V, is __________.

For the operational amplifier circuit shown, the output saturation voltages are $$ \pm \,\,15V$$. The upper and lower threshold voltages for the circuit are, respectively.

In a digital communication system, the overall pulse shape p(t) at the receiver before the sampler has the Fourier transform P(f). If the symbols are transmitted at the rate of 2000 symbols per second, for which of the following cases is inter symbol interference zero?