GATE CSE 2019 | Question: 50

Question

What is the minimum number of $2$-input NOR gates required to implement a $4$ -variable function expressed in sum-of-minterms form as $f=\Sigma(0,2,5,7, 8, 10, 13, 15)?$ Assume that all the inputs and their complements are available. Answer: _______

Comments

@mrinmoyh 4 NOR gates are required when complemented inputs are not available.

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Here important statement given in question is:

Assume that all the inputs and their complements are available.

If complements are NOT available then minimum $4$ NOR gates($2$ – input) are required to implement Ex – NOR.

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Fascinated

Answer 1

.........................

 

Answer 2

 

1			1
	1	1
	1	1
1			1

this simplifies to X-NOR equation which require 4 nor gate but compliment is given explicitely

so, 3 nor gates required

Comments

Ans is 3
Pass X,Y' from first Nor gate
Pass Y,X' from second Nor gate
then pass output of first and second gate to 3rd nor gate you will get (X+Y')(x'+Y)

Answer 3

Ans is 4

Comments

balchandar reddy san bro its till 4 .....

see my answer ...... and who downvote on above  diagram it is correct

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could you just tell me what is the o/p for the above circiut?

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found mistake

Answer 4

Answer should be 4.