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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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Official PYQ1999Digital LogicNumber Representations (Fixed and Floating Point)MSQ · 1 mark
Zero has two representations in
Official PYQ1999Digital LogicComputer ArithmeticMCQ · 1 mark
The number of full and half-adders required to add 1616-bit numbers is
Official PYQ1999Digital LogicBoolean AlgebraMSQ · 1 mark
Which of the following sets of component(s) is/are sufficient to implement any arbitrary Boolean function?
Official PYQ1999Digital LogicCombinational CircuitsMCQ · 1 mark
Consider the circuit shown below. In a certain steady state, the line YY is at ′1′'1'. What are the possible values of A,BA, B and CC in this state?
Official PYQ1999Digital LogicComputer ArithmeticMCQ · 1 mark
The maximum gate delay for any output to appear in an array multiplier for multiplying two nn bit numbers is
Official PYQ1999Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
Booth's coding in 88 bits for the decimal number −57-57 is:
Official PYQ1999Digital LogicMinimization (K-Maps etc.)MCQ · 1 mark
Which of the following functions implements the Karnaugh map shown below?
Official PYQ1999Digital LogicBoolean AlgebraMCQ · 1 mark
Which of the following expressions is not equivalent to xˉ\bar{x}?
Official PYQ1998Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
Suppose the domain set of an attribute consists of signed four digit numbers. What is the percentage of reduction in storage space of this attribute if it is stored as an integer rather than in character form?
Official PYQ1998Digital LogicBoolean AlgebraMCQ · 1 mark
Which of the following operations is commutative but not associative?
Official PYQ1998Digital LogicMinimization (K-Maps etc.)MCQ · 1 mark
The function represented by the Karnaugh map given below is
Official PYQ1998Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
The octal representation of an integer is (342)8(342)_8. If this were to be treated as an eight-bit integer in an 80858085 based computer, its decimal equivalent is
Official PYQ1998Digital LogicCombinational CircuitsMCQ · 1 mark
The threshold level for logic 1 in the TTL family is
Official PYQ1998Digital LogicCombinational CircuitsMCQ · 1 mark
A multiplexer with a 4−bit4-bit data select input is a
Official PYQ1998Digital LogicBoolean AlgebraMCQ · 1 mark
What happens when a bit-string is XORed with itself nn-times as shown: [B⊕(B⊕(B⊕(B…n times]\left[B \oplus (B \oplus ( B \oplus (B \dots n \text{ times}\right]
Official PYQ1997Digital LogicMinimization (K-Maps etc.)NAT · 1 mark
Let f=(wˉ+y)(xˉ+y)(w+xˉ+z)(wˉ+z)(xˉ+z)f=(\bar{w} + y)(\bar{x} +y)(w+\bar{x}+z)(\bar{w}+z)(\bar{x}+z) Express ff as the minimal sum of products. Write only the answer. If the output line is stuck at 00, for how many input combinations will the value of ff be correct?
Official PYQ1997Digital LogicCombinational CircuitsMCQ · 1 mark
Consider a logic circuit shown in figure below. The functions f1,f2 and ff_1, f_2 \text{ and } f (in canonical sum of products form in decimal notation) are : f1(w,x,y,z)=∑8,9,10f_1 (w, x, y, z) = \sum 8, 9, 10 f2(w,x,y,z)=∑7,8,12,13,14,15f_2 (w, x, y, z) = \sum 7, 8, 12, 13, 14, 15 f(w,x,y,z)=∑8,9f (w, x, y, z) = \sum 8, 9 The function f3f_3 is
Official PYQ1997Digital LogicNumber Representations (Fixed and Floating Point)MCQ · 1 mark
Given (224)r=(13)r\sqrt{(224)_r} =(13)_r. The value of the radix rr is:
Official PYQ1997Digital LogicMinimization (K-Maps etc.)MCQ · 1 mark
Let f(x,y,z)=xˉ+yˉx+xzf(x, y, z)=\bar{x} + \bar{y}x + xz be a switching function. Which one of the following is valid?
Official PYQ1997Digital LogicComputer ArithmeticMCQ · 1 mark
An N-bit carry lookahead adder, where NN is a multiple of 44, employs ICs 7418174181 (44 bit ALU) and 7418274182 ( 44 bit carry lookahead generator). The minimum addition time using the best architecture for this adder is