1

GATE ECE 2018

Numerical

+2

-0.67

The logic gates shown in the digital circuit below use strong pull-down nMOS transistors for
LOW logic level at the outputs. When the pull-downs are off, high-value resistors set the
output logic levels to HIGH (i.e. the pull-ups are weak). Note that some nodes are
intentionally shorted to implement “wired logic”. Such shorted nodes will be HIGH only if
the outputs of all the gates whose outputs are shorted are HIGH.

The number of distinct values of X

The number of distinct values of X

_{3}X_{2}X_{1}X_{0}(out of the 16 possible values) that give 𝑌 = 1 is _______.Your input ____

2

GATE ECE 2015 Set 3

MCQ (Single Correct Answer)

+2

-0.6

A universal logic gate can implement any Boolean function by connecting sufficient number of
them appropriately. Three gates are shown.

Which one of the following statesments is TRUE?

3

GATE ECE 2015 Set 1

Numerical

+2

-0

All the logic gates shown in the figure have a propagation delay of 20 ns. Let A = C = 0 and B = 1
until time t = 0. At t = 0, all the inputs flip (i.e., A = C = 1 and B = 0) and remain in that state. For
t > 0, output Z = 1 for a duration (in ns) of ______________.

Your input ____

4

GATE ECE 2015 Set 1

MCQ (Single Correct Answer)

+2

-0.6

A 3-input majority gate is defined by the logic function M (a,b,c) = ab+bc+ca. Which one of
the following gates is represented by the function M$$\left( {\overline {M\left( {a,b,c} \right),} M\left( {a,b,\overline c } \right),c} \right)?$$

Questions Asked from Logic Gates (Marks 2)

Number in Brackets after Paper Indicates No. of Questions

GATE ECE Subjects

Signals and Systems

Representation of Continuous Time Signal Fourier Series Fourier Transform Continuous Time Signal Laplace Transform Discrete Time Signal Fourier Series Fourier Transform Discrete Fourier Transform and Fast Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Discrete Time Linear Time Invariant Systems Transmission of Signal Through Continuous Time LTI Systems Sampling Transmission of Signal Through Discrete Time Lti Systems Miscellaneous

Network Theory

Control Systems

Digital Circuits

General Aptitude

Electronic Devices and VLSI

Analog Circuits

Engineering Mathematics

Microprocessors

Communications

Electromagnetics