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GATE CS Boolean Algebra questions

Practise Boolean Algebra questions for GATE CS. Explore official PYQs and original topic-wise quizzes, check answers and view available solutions. Free, no sign-in.

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Official PYQ2026Digital LogicBoolean AlgebraMSQ · 1 mark
Consider the following Boolean expression of a function FF : F(P,Q)=(Pˉ+Q)⊕(PˉQ)F(P, Q)=(\bar{P}+Q) \oplus(\bar{P} Q) Which of the following expressions is/are equivalent to FF ?
Official PYQ2026Digital LogicBoolean AlgebraMCQ · 1 mark
Which one of the following options is not a property of Boolean Algebra? Note: +{+} is OR operation, ⋅\cdot is AND operation, and ′{\prime} is NOT operation
Official PYQ2025Digital LogicBoolean AlgebraMSQ · 1 mark
Let XX be a 33-variable Boolean function that produces output as ′1′'1' when at least two of the input variables are ′1′'1'. Which of the following statement(s) is/are CORRECT, where a,b,c,d,ea, b, c, d, e are Boolean variables?
Official PYQ2025Digital LogicBoolean AlgebraMSQ · 2 marks
Which of the following Boolean algebraic equation(s) is/are CORRECT?
Official PYQ2024Digital LogicBoolean AlgebraMSQ · 1 mark
​​​​For a Boolean variable xx, which of the following statements is/are FALSE?
Official PYQ2021Digital LogicBoolean AlgebraMSQ · 2 marks
Consider the following Boolean expression. F=(X+Y+Z)(X‾+Y)(Y‾+Z)F=(X+Y+Z)(\overline X +Y)(\overline Y +Z) Which of the following Boolean expressions is/are equivalent to F‾\overline F (complement of FF)?
Official PYQ2021Digital LogicBoolean AlgebraNAT · 2 marks
Consider a Boolean function f(w,x,y,z)f(w,x,y,z) such that f(w,0,0,z)=1f(1,x,1,z)=x+zf(w,1,y,z)=wz+y\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 ff is _________
Official PYQ2020Digital LogicBoolean AlgebraMCQ · 2 marks
Consider the Boolean function z(a,b,c)z(a,b,c). Which one of the following minterm lists represents the circuit given above?
Official PYQ2019Digital LogicBoolean AlgebraMCQ · 1 mark
Which one of the following is NOT a valid identity?
Official PYQ2019Digital LogicBoolean AlgebraMCQ · 2 marks
Consider three 44-variable functions f1,f2f_1, f_2, and f3f_3, which are expressed in sum-of-minterms as f1=Σ(0,2,5,8,14),f_1=\Sigma(0,2,5,8,14), f2=Σ(2,3,6,8,14,15),f_2=\Sigma(2,3,6,8,14,15), f3=Σ(2,7,11,14)f_3=\Sigma (2,7,11,14) For the following circuit with one AND gate and one XOR gate the output function ff can be expressed as:
Official PYQ2019Digital LogicBoolean AlgebraNAT · 2 marks
What is the minimum number of 22-input NOR gates required to implement a 44 -variable function expressed in sum-of-minterms form as f=Σ(0,2,5,7,8,10,13,15)?f=\Sigma(0,2,5,7, 8, 10, 13, 15)? Assume that all the inputs and their complements are available. Answer: _______
Official PYQ2018Digital LogicBoolean AlgebraMCQ · 1 mark
Let ⊕\oplus and ⊙\odot denote the Exclusive OR and Exclusive NOR operations, respectively. Which one of the following is NOT CORRECT?
Official PYQ2017Digital LogicBoolean AlgebraMCQ · 1 mark
If w,x,y,zw, x, y, z are Boolean variables, then which one of the following is INCORRECT?
Official PYQ2016Digital LogicBoolean AlgebraMCQ · 1 mark
Consider the Boolean operator # with the following properties : x#0=x,x#1=x‾,x#x=0x \# 0 = x, x \# 1=\overline{x}, x \# x = 0 and x#x‾=1.x \# \overline{x} = 1. Then x#yx\#y is equivalent to
Official PYQ2016Digital LogicBoolean AlgebraMCQ · 1 mark
Let, x1⊕x2⊕x3⊕x4=0x_{1} ⊕ x_{2} ⊕ x_{3} ⊕ x_{4}= 0 where x1,x2,x3,x4x_{1}, x_{2}, x_{3}, x_{4} are Boolean variables, and ⊕⊕ is the XOR operator. Which one of the following must always be TRUE?
Official PYQ2015Digital LogicBoolean AlgebraMCQ · 1 mark
Consider the operations f (X, Y, Z) = X’YZ + XY’ + Y’Z’\textit{f (X, Y, Z) = X'YZ + XY' + Y'Z'} and g (X, Y, Z) = X’YZ + X’YZ’ + XY\textit{g (X, Y, Z) = X'YZ + X'YZ' + XY} Which one of the following is correct?
Official PYQ2015Digital LogicBoolean AlgebraNAT · 1 mark
The number of min-terms after minimizing the following Boolean expression is _______. [D′+AB′+A′C+AC′D+A′C′D]′[D'+AB'+A'C+AC'D+A'C'D]'
Official PYQ2015Digital LogicBoolean AlgebraMCQ · 1 mark
Given the function F=P′+QRF = P' +QR, where FF is a function in three Boolean variables P,QP, Q and RR and P′=!PP'=!P, consider the following statements. (S1)F=∑(4,5,6)(S1) F = \sum(4, 5, 6) (S2)F=∑(0,1,2,3,7)(S2) F = \sum(0, 1, 2, 3, 7) (S3)F=Π(4,5,6)(S3) F = \Pi (4, 5, 6) (S4)F=Π(0,1,2,3,7)(S4) F = \Pi (0, 1, 2, 3, 7) Which of the following is true?
Official PYQ2015Digital LogicBoolean AlgebraNAT · 1 mark
The total number of prime implicants of the function f(w,x,y,z)=∑(0,2,4,5,6,10)f(w, x, y, z) = \sum (0, 2, 4, 5, 6, 10) is __________
Official PYQ2014Digital LogicBoolean AlgebraMCQ · 1 mark
The dual of a Boolean function F(x1,x2,…,xn,+,.,′)F(x_1,x_2,\dots,x_n,+, .,'), written as FDF^D is the same expression as that of FF with ++ and ⋅⋅ swapped. FF is said to be self-dual if F=FDF = F^D. The number of self-dual functions with nn Boolean variables is