UGC NET CSE | June 2014 | Part 3 | Question: 42

Question

The output of a sequential circuit depends on

• A. Present input only
• B. Past input only
• C. Both present and past input
• D. Past output only 

Answer 1

sequential logic is a type of logic circuit whose output depends not only on the present value of its input signalsbut on the sequence of past inputs, the input history.This is in contrast to combinational logic, whose output is a function of only the present input. That is, sequential logic has state(memory) while combinational logic does not. Or, in other words, sequential logic is combinational logic with memory.

Hence,Option(C)Both present and Past input.

Answer 2

There are 2 types of circuits 1) Combinational and 2)Sequential

Combinational circuits are those whose output depends upon current input like ADDER, SUBTRACTOR ,MUX , DEMUX , ENCODER,DECODER etc 

Seqential circuits are those whose output depends on both current and previous input

 e.g. Register,Counter etc they contain memory element Flip-Flop

Hence Ans is C

Answer 3

option is C

In digital circuit theory, sequential logic is a type of logic circuit whose output depends not only on the present value of its input signals but on the past history of its inputs.