Digital Logic


Q1.

The following circuit compares two 2-bit binary numbers, X and Y represented by X_{1}X_{0} and Y_{1}Y_{0} respectively. (X_{0} and Y_{0} represent Least Significant Bits)Under what conditions Z will be 1?
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Q2.

Any set of Boolean operation that is sufficient to represent all Boolean expression is said to be complete. Which of the following is not complete ?
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Q3.

Consider the following Boolean expression. F=(X+Y+Z)(\overline X +Y)(\overline Y +Z) Which of the following Boolean expressions is/are equivalent to \overline F (complement of F)?[MSQ]
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Q4.

What is the minimum number of 2-input NOR gates required to implement 4-variable function expressed in sum-of-minterms from as f = \Sigma (0, 2, 5, 7, 8, 10, 13, 15)? Assume that all the inputs and their complements are available. Answer ________ .
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Q5.

Consider three 4-variable functions f_1,f_2 \; and \; f_3, which are expressed in sum-of-minterms f_1=\Sigma (0,2,5,8,14) f_2=\Sigma (2,3,6,8,14,15) f_3=\Sigma (2,7,11,14) For the following circuit with one AND gate and one XOR gate, the output function f can be expressed as:
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Q6.

Minimum number of NAND gates required to implement the following binary equationY=(\bar{A}+\bar{B})(C+D)
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Q7.

Which one of the following is NOT a valid identity?
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Q8.

If ABCD is a 4-bit binary number, then what is the code generated by the following circuit?
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Q9.

Consider the Boolean function z(a,b,c). Which one of the following minterm lists represents the circuit given above?
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Q10.

Consider a Boolean function f(w,x,y,z) such that \begin{array}{lll} f(w,0,0,z) & = & 1 \\ f(1,x,1,z) & =& x+z \\ f(w,1,y,z) & = & wz +y \end{array} The number of literals in the minimal sum-of-products expression of f is ________
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