If the input X$$_3$$, X$$_2$$, X$$_1$$, X$$_0$$ to the ROM in figure 2.12 are 8-4-2-1 BCD numbers, then the outpus are Y$$_3$$,Y$$_2$$, Y$$_1$$, Y$$_0$$ are

4-bit 2’s complement representation of a decimal number is 1000. The number is

If the input to the digital circuit (in the figure) consisting of a cascade of 20 XOR-gates is X then the output Y is equal to

The gates G₁ and G₂ in figure have propagation delays of 10nsec and 20nsec respectively. If the input V_i makes an abrupt change from logic 0 to 1 at time t = t₀, then the output waveform V₀ is