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GATE CS Digital Logic questions

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

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20 on this page
Official PYQ2003Digital LogicComputer ArithmeticMCQ · 1 mark
Consider an array multiplier for multiplying two nn bit numbers. If each gate in the circuit has a unit delay, the total delay of the multiplier is
Official PYQ2003Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
Assuming all numbers are in 2’s2’s complement representation, which of the following numbers is divisible by 1111101111111011?
Official PYQ2002Digital LogicBoolean AlgebraMCQ · 1 mark
Let f(A,B)=A′+Bf(A,B) = A'+B. Simplified expression for function f(f(x+y,y),z)f(f(x+y, y), z) is
Official PYQ2002Digital LogicCombinational CircuitsMCQ · 1 mark
Consider the following multiplexer where I0,I1,I2,I3I0, I1, I2, I3 are four data input lines selected by two address line combinations A1A0=00,01,10,11A1A0=00,01,10,11 respectively and ff is the output of the multiplexor. EN is the Enable input. The function f(x,y,z)f(x,y,z) implemented by the above circuit is
Official PYQ2002Digital LogicCombinational CircuitsMCQ · 1 mark
Consider the following logic circuit whose inputs are functions f1,f2,f3f_1, f_2, f_3 and output is ff Given that f1(x,y,z)=Σ(0,1,3,5)f_1(x,y,z) = \Sigma (0,1,3,5) f2(x,y,z)=Σ(6,7),f_2(x,y,z) = \Sigma (6,7), and f(x,y,z)=Σ(1,4,5).f(x,y,z) = \Sigma (1,4,5). f3f_3 is
Official PYQ2002Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
In 2′s2's complement addition, overflow
Official PYQ2002Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
Sign extension is a step in
Official PYQ2002Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
The decimal value 0.250.25
Official PYQ2002Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
The 2′s2's complement representation of the decimal value −15-15 is
Official PYQ2002Digital LogicMinimization (K-Maps etc.)MCQ · 1 mark
Minimum sum of product expression for f(w,x,y,z)f(w,x,y,z) shown in Karnaugh-map below
Official PYQ2001Digital LogicSequential CircuitsMCQ · 1 mark
Consider the circuit given below with initial state Q0=1,Q1=Q2=0Q_0=1, Q_1=Q_2=0. The state of the circuit is given by the value 4Q2+2Q1+Q04Q_2+2Q_1+Q_0 Which one of the following is correct state sequence of the circuit?
Official PYQ2001Digital LogicCombinational CircuitsMCQ · 1 mark
Consider the circuit shown below. The output of a 2:12:1 MUX is given by the function (ac′+bc)(ac' + bc). Which of the following is true?
Official PYQ2001Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
The 2′s2's complement representation of (-539)10 in hexadecimal is
Official PYQ2001Digital LogicCombinational CircuitsMCQ · 1 mark
Consider the following circuit with initial state Q0=Q1=0Q_0 = Q_1 = 0. The D Flip-flops are positive edged triggered and have set up times 20 nanosecond and hold times 0.0. Consider the following timing diagrams of X and C. The clock period of C≥40C \geq 40 nanosecond. Which one is the correct plot of Y?
Official PYQ2001Digital LogicMinimization (K-Maps etc.)MCQ · 1 mark
Given the following karnaugh map, which one of the following represents the minimal Sum-Of-Products of the map?
Official PYQ2000Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
Consider the values of A=2.0×1030,B=−2.0×1030,C=1.0,A = 2.0 \times 10^{30}, B = -2.0 \times 10^{30}, C = 1.0, and the sequence X:= A + B Y:= A + C X:= X + C Y:= Y + B executed on a computer where floating point numbers are represented with 3232 bits. The values for XX and YY will be
Official PYQ2000Digital LogicSequential CircuitsMCQ · 1 mark
The following arrangement of master-slave flip flops has the initial state of P,QP, Q as 0,10, 1 (respectively). After three clock cycles the output state P,QP, Q is (respectively),
Official PYQ2000Digital LogicMinimization (K-Maps etc.)MCQ · 1 mark
Which functions does NOT implement the Karnaugh map given below?
Official PYQ2000Digital LogicBoolean AlgebraMCQ · 1 mark
The simultaneous equations on the Boolean variables x,y,zx, y, z and ww, x+y+z=1x + y + z = 1 xy=0xy = 0 xz+w=1xz + w = 1 xy+zˉwˉ=0xy + \bar{z}\bar{w} = 0 have the following solution for x,y,zx, y, z and w,w, respectively:
Official PYQ2000Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
The number 4343 in 2′s2's complement representation is