1

GATE ECE 1993

Subjective

+10

-0

Signals A,B,C,D and $$\overline D $$ are available. Using a single 8 - to - 1 multiplexer and no other gate, implement the Boolean function.

$$f(A,B,C,D) = B.C + A.B.\bar D + \bar A.\bar C.\bar D$$

$$f(A,B,C,D) = B.C + A.B.\bar D + \bar A.\bar C.\bar D$$

2

GATE ECE 1989

Subjective

+10

-0

A chemical reactor has three sensors indicating the following conditions:-

(1) Pressure (P) is low or high'

(2) Temperature (T) is low or high' and

(3) Liquid level (L) is low or high.

(1) Pressure (P) is low or high'

(2) Temperature (T) is low or high' and

(3) Liquid level (L) is low or high.

its has two controls - Heater (H) which is either on or off and inlet value (V) which is open or close. The controls are operated as per Table.

(a) Using the convertion High =1, Low = 0, On=1, Off=0, Open=1 and Closed=0, draw the Karnaugh maps for H and V.

(b) Obtain the minimal product of sums expressions for H and V.

(c) Realize the logic for H and V using two 4-input multiplexers with T and L as control inputs. Used T as MSB.

Questions Asked from Combinational Circuits (Marks 10)

Number in Brackets after Paper Indicates No. of Questions

GATE ECE Subjects

Network Theory

Control Systems

Electronic Devices and VLSI

Analog Circuits

Digital Circuits

Microprocessors

Signals and Systems

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

Communications

Electromagnetics

General Aptitude