Digital Circuits
Number System and Code Convertions
Marks 1Marks 2
Sequential Circuits
Marks 1Marks 2Marks 5Marks 8
Semiconductor Memories
Marks 1Marks 2
Logic Families
Marks 1Marks 2Marks 8
Analog to Digital and Digital to Analog Converters
Marks 1Marks 2
1
GATE ECE 1992
Subjective
+8
-0
A combinational circuit has three inputs A, B and C and an output F. F is true only for the following input combinations?

A is false and B is true
A is false and C is true
A, B and C are all false
A, B and C are all true.

(a)Write the truth table for F. use the convention, true = 1 and false = 0.
(b)Write the simplified expression for F as a Sum of Products.
(c) Write the simplified expression for F as a product of Sums.
(d) Draw a logic circuit implementation of F using the minimum number of 2 input NAND gates only.

Questions Asked from Marks 8
GATE ECE Subjects
Signals and Systems
Network Theory
Control Systems
Digital Circuits
General Aptitude
Electronic Devices and VLSI
Analog Circuits
Engineering Mathematics
Microprocessors
Communications
Electromagnetics